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Race Day Fueling

Category:fuel,nutrition,performance,race day

Ah race day. The day you’ve been waiting for. The day that puts all your hard work and training to the test. You’ve done everything to prepare physically and now it’s time to see it pay off. Except… You still have one very important job left to do: prepare your race day nutrition strategy. Far too often, we (as dietitians) have seen athletes work their tails off in training, only to sabotage their race day performance by lack of nutrition preparation and execution, particularly when it comes to events of longer duration (>1hr). You see, good performance is dependent upon gas in the tank and that tank has a limited capacity, which means more fuel needs to be added along the way in order to sustain performance and prevent a breakdown. Moreover, the quality and quantity of fuel is important to maximize speed and efficiency of travel, not to mention the role of timing. As you can see, there are a lot of factors that come into play on race day, and we want to make sure you have a good grip on the wheel if you catch our drift (no pun intended). In this article, we are going to break down the what, when, and how much of pre-, during and post-race nutrition so you can be in the drivers seat when it’s your time to shine.

Pre-race:

If you missed our previous blog post regarding carbohydrate loading and race week nutrition, we highly recommend that you go back and visit that article prior to race day to ensure you’re taking the necessary steps to prepare yourself nutritionally in advance, as the days leading up to a race are of particular importance. However, now that we’re here and focused on race day, let’s start with breakfast and pre-race fueling protocol. First off, no questions asked, you must eat breakfast on race morning. When you sleep, our body’s liver glycogen (storage form of carbohydrates) stores provide our brain and other organs with energy to carry out various bodily processes. Carbohydrate consumed in the 4-hr period pre exercise may increase body glycogen stores if these are suboptimal due to overnight fast, particularly in the liver (Thomas et al., 2016). Under most circumstances, pre-race breakfast is really the last opportunity to top off these stores prior to go-time. What you eat at breakfast will also be the fuel your body utilizes first during the early stages of your race, so it’s kind of a big deal.

Now that we’re in agreement regarding the importance of pre-race breakfast, let’s get into the nitty gritty of what, when and how much. As we also discussed in great length in our “Race Week- Carbohydrate Loading” article, carbohydrates are going to be the primary focus for this meal. The reason being: carbohydrates are the body’s preferred and most efficient fuel source, especially at high intensities (which is often the stimulus for most races). The timing of your meal will determine the quantity of carbohydrate, as well as, to some extent, the type (complex vs simple carbs). Most pre-race breakfast options include a variety of simple and complex carbohydrates, as “complex” sources provide more sustained energy but take longer to digest and process, while “simple” sources provide immediate energy. The 2018 International Olympic Committee consensus statement recommends 1-4 g/kg of carbohydrate 1-4 hours prior to an event. This means that if you consume breakfast 4 hours prior to the race start, your aim should be to consume 4 g/kg of carbohydrate. If you have 2 hours until race time, your goal is 2 g/kg carbohydrate. As always, these recommendations should be tailored with individual considerations, and timing of food intake around activity should be practiced well in advance to race day.

As a note, pre-race fueling recommendations focus primarily on carbohydrates, as this is the body’s primary/preferred fuel source. Foods high in fat, protein and fiber may need to be avoided to reduce risk of GI issues during the event.

During the Race:

The starting gun has sounded and you’re off like a rocket! Finally, you can set out to accomplish what you came here to do- race! The only thing that lies between you and the finish line are a bunch of obstacles and gnarly terrain. Time to focus on the physical! Except… you still can’t forget about fueling, particularly for longer races (>1-hr). An individual’s fueling strategy during competition can largely determine his/her performance outcome, which is always unfortunate to witness because it’s something completely controllable.

There is significant evidence of performance enhancement using strategies to maintain high carbohydrate availability during prolonged sustained or intermittent high-intensity exercise, whereas the depletion of endogenous glycogen stores is associated with fatigue in the form of reduced work rate, impaired skill concentration and increased perception of effort (Thomas et al., 2016). In a nutshell, fueling with carbohydrates is essential for those looking to perform.

We will cover the many different kinds of carbohydrate options out there and what scenarios are best to use which in our next blog post, but for now, let’s talk about amount and timing. We’ve broken down the essentials in a chart below to make things simple. Most obstacle course races that fall in the 1-3 hour range will require 30-60 grams of carbohydrate per hour.

A common mistake racers often make is fueling too late. These recommendations start the very first hour, so even though food might be the last thing on your mind 30 minutes into a race, you need to stay ahead on your calorie intake to prevent from bonking, particularly the longer the race. Most sports gels/gu’s and other carbohydrate supplements targeted for mid-race fueling contain ~20-30 grams of carbohydrates per serving, which makes things easy for the racer. To space out carbohydrate doses and minimize GI upset, a good rule of thumb is to consume 20-30 grams of carbohydrate every ~30min. The average person can oxidize glucose (carbohydrate) at a rate of 1 gram/minute, so over the course of an hour, that comes out to 60 grams of oxidized glucose. This oxidation rate is limited by intestinal glucose absorption, so an intake of carbohydrate above 60 g/hr will likely cause GI upset and decrease performance.

Post-race:

You made it! The race is over, you’re exhausted and dirty, but the sense of accomplishment brings a smile to your face that you can’t wipe off no matter how hard you scrub. You have zero plans for the rest of the day but to hang with friends, cheer on other racers out on course, kick your feet up, eat lots of food, and eventually shower.

While it’s likely you’ll be quite hungry after the race and already be thinking about food, this isn’t our first rodeo (we know how things work). You have every intention of getting something in your belly, but then you visit with friends in the venue area, share race stories, cheer on fellow racers at the rig, check out the vendor village, and before you know it, an hour (or two) has flown by. All of those activities are what makes the OCR experience so much fun, and we fully support doing all of them, but we are here to be your nutrition guides, and so we must emphasize the importance of a post-race snack/meal as soon as possible upon finishing.

There are a few reasons why this post-race snack and/or meal is essential. First off, for replenishment. We expend a lot of energy/calories during exercise, especially in a race/competition setting when exertion is high. The primary focus of this article has been on carbohydrates, so it makes sense that when it comes to replenishment, we should also think carbohydrates! By restoring our muscle glycogen levels, we are not only providing our muscles with the support to engage in other (future) physical activity, we’re also helping them recover. This brings us to reason number two: recovery! During physical activity (particularly intense and/or sustained activity), our muscles face resistance, in some capacity, which leads to microscopic tears within the muscle tissue. While this is a normal phenomena of exercise and part of muscular adaptation, proper nutrition protocol following exercise has the ability to aid in the recovery process by repairing damaged tissue, which leads us to our third reason: repair! This is where dietary protein comes into play. Research shows that, in response to exercise, the maintenance, repair and synthesis of skeletal muscle proteins is optimized with the consumption of high quality protein, and should therefore be included in post-exercise nutrition protocol (Thomas et al., 2016).

To maximize recovery and support the repair/remodeling process, we recommend consuming 15-25 g of protein with ~1 g/kg body weight of carbohydrate (banana, energy bar, bagel, muffin etc.) as soon as possible within finishing your race, followed by a well-balanced meal within 1.5-2 hours (Thomas et al., 2016) (Burke, et al., 2017). See chart below for specific recommendations.

Conclusion:

We hope you now feel more confident about your race day fueling strategy and have a better understanding of the “why” behind these nutrition protocols. In the following weeks, we will continue with our “Race Day Fueling” theme and provide more details on this topic. In the meantime, we recommend putting these strategies into practice during training so come race day, you can feel confident in your game plan and its execution. As always, our Yancy Camp Nutrition team is here to help, so don’t hesitate to contact us.

References:

Burke, L. M., Loon, L. J., & Hawley, J. A. (2017). Postexercise muscle glycogen resynthesis in humans. Journal of Applied Physiology,122(5), 1055-1067. https://doi.org/10.1152/japplphysiol.00860.2016

Thomas, D. T., Erdman, K. A., & Burke, L. M. (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance. Journal of the Academy of Nutrition & Dietetics,16, 501-528. http://doi.org/10.1016/j.jand.2015.12.006.

Yeo, S. E., Jentjens, R. L., Wallis, G. A., & Jeukendrup, A. E. (2005). Caffeine increases exogenous carbohydrate oxidation during exercise. Journal of Applied Physiology,99(3), 844-850. https://doi.org/10.1152/japplphysiol.00170.2005

YCN Event-Based Carb Recommendations by Corinna Coffin, MS, RD

Race Week Nutrition: Sample Meal Plan (Carb Loading)

Category:carbohydrate loading,fuel,nutrition,performance,race week

We realize it’s rather easy to throw out a bunch of numbers when it comes to nutrition recommendations, but a heck of a lot harder to translate those into food choices throughout a given day. This task can be especially arduous when following race week carbohydrate-loading protocol, as carbohydrate recommendations are particularly high. Below, we have created a sample meal plan template (based off of a 150-lb individual) to help give some sort of visual reference for what a typical day might look like in order to achieve these carbohydrate goals in the 24-48 hours leading up to an important race/event.

The left-hand “Base Carbs” column shows one possible meal/snack layout during a 24-hour period to meet ~7 g CHO/kg body weight (the lower end of carbohydrate-loading recommendations for events lasting < 90 minutes). On the right-hand “Revised to Add Carbs” column, we have taken essentially the same meal/snack layout as the “Base Carbs” column, but made a few tweaks/additions in order to meet an increased carbohydrate target of ~10 g/kg body weight, which falls in the upper range of carbohydrate-loading recommendations for events lasting < 90 minutes and in the lower range of those lasting > 90 minutes. As always when it comes to generalized nutrition information, recommendations should be tailored to the individual based on his/her total energy needs, specific training needs, and performance feedback.

Race-week Nutrition: Carbohydrate Loading

Category:carbohydrate loading,carbohydrates,fuel,performance

Dietary manipulation is an integral aspect of an athlete’s training protocol, particularly as it relates to performance outcomes. High-carbohydrate diets are best-recognized for performance improvements in both sustained, low-to-moderate and short, high-intensity exercises, which can be attributed to maximizing muscle glycogen content (the storage form of carbohydrate) and thereby its availability for utilization during exercise. An individual’s capacity to perform prolonged, heavy exercise is largely determined by the glycogen content of the working muscles, which we know can be appreciably varied depending on the instituted dietary protocol (Michalczyk et al., 2019).

This concept of carbohydrate availability is key for optimizing performance. “High carbohydrate availability” is achieved when total daily intake and the timing of intake in relation to exercise maintain sufficient carbohydrate substrate for the muscle and central nervous system. An individual’s carbohydrate consumption and overall fueling plan in the hours or days prior an event, during exercise, and between consecutive exercise sessions are all methods for increasing carbohydrate availability (Burke et al., 2011). When adequate intake is not achieved and carbohydrate substrate is limiting for the intended exercise program, this is referred to as “low carbohydrate availability.” Some athletes and coaches purposely utilize a low carbohydrate availability approach in training, known as the “train low” theory, in order to achieve enhanced cellular signaling and metabolic adaptation; however, research has yet to show performance improvements using this methodology (Burke et al., 2011).

In the days/week leading up to an important race or event, it’s important to adjust one’s training and nutrition protocol to maximize muscle glycogen content. It is widely accepted that several days of increased carbohydrate intake, in combination with a reduction in exercise (“taper”), will result in elevated glycogen content in the muscles that are frequently active in training (Burke et al., 2011). This nutrition strategy to ensure adequate muscle glycogen stores in preparation for an event is referred to as “carbohydrate loading.”

Under optimal carbohydrate loading conditions, an athlete begins his/her session with glycogen stores that correspond with the estimated fuel costs of the event (Burke et al., 2011). The body stores glycogen in two primary areas: muscle and the liver. In total, our muscles can store up to ~400g of glycogen (carbs), while the liver can store an additional ~100 g, giving us a total of ~500 grams (or 2,000 calories) of stored carbohydrate. Workout intensity and duration are the primary factors involved in muscle glycogen depletion; although, depending on how full glycogen stores were prior to commencement, this can compromise performance or not.

There is significant evidence that shows an association between depleted muscle glycogen stores and fatigue, particularly related to reduced work output, impaired skill and concentration and increased perception of effort (Thomas et al., 2016). Compared to “normal” diets (those within recommended carbohydrate range), carbohydrate-loading regimens are associated with improved endurance times to exhaustion, especially at higher intensities (>65% VO2max) and longer durations (>90 min).

For events lasting less than 90 minutes, high glycogen concentrations can be achieved with as little as 24 hours of rest and high carbohydrate intake, between 7-12 g/kg/24 hr. Events lasting longer than 90 minutes may require 36-48 hours of high carbohydrate intake, between 10-12 g/kg/24 hr (Thomas et al., 2016). On occasions where exercise quality or intensity is less important, achieving these carbohydrate targets may be less important (Thomas et al., 2016).

It’s important to note that these are general recommendations which should be tailored to an individual in consideration of his/her total energy and training needs, as well as performance feedback. This is where working with a Sports Dietitian can be especially helpful, as proper fueling strategies for important events involve careful planning, a lot of carbs, and a smart approach. As always, your Yancy Camp dietitians are here to help!

References:

Burke, L. M., Hawley, J. A., Wong, S. H. S., & Jeukendrup, A. E. (2011): Carbohydrates for training and competition, Journal of Sports Sciences, 29:sup1, S17-S27 http://dx.doi.org/10.1080/02640414.2011.585473

Michalczyk, M., Chycki, J., Zajac, A., Maszczyk, A., Zydek, G., & Langfort, J. (2019). Anaerobic performance after a low-carbohydrate diet (LCD) followed by 7 days of carbohydrate loading in male basketball players. Nutrients,11(4), 778. http://doi.org/10.3390/nu11040778

Thomas, D. T., Erdman, K. A., & Burke, L. M. (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance. Journal of the Academy of Nutrition & Dietetics,16, 501-528. http://doi.org/10.1016/j.jand.2015.12.006.

YC Nutrition: The Effects of Alcohol on Training, Performance...

Effects of Alcohol Consumption on Training, Performance and Body Composition

Category:alcohol,body composition,nutrition,performance

When it comes to health and athletic performance, both acute and chronic alcohol use can have deleterious effects. The large variance in the effects of alcohol within and across individuals can be attributed to several factors such as genetics, gender, amount of alcohol ingested, body mass and nutrition status (Barnes, 2014) . Acute alcohol consumption can influence motor skills, hydration status, aerobic performance and certain aspects of the recovery process. Chronic alcohol use can have more serious repercussions including nutritional deficiencies and depressed immune function, resulting in increased risk of injury and prolonged healing (Barnes, 2014) .

Upon ingestion, ethanol (the chemical name for alcohol) is readily absorbed all throughout the gastrointestinal (GI) tract, with 25% absorbing straight from the stomach into the bloodstream (Cederbaum, 2012). The rate of absorption into the bloodstream depends on a few factors, namely the amount of food in the stomach (more food present slows the absorption rate) and the alcohol content of the drink (a higher alcohol content increases the rate). The remaining 75% is metabolized primarily in the liver. Ethanol metabolism produces the toxic byproducts acetaldehyde and acetate (Cederbaum, 2012). Although generally short-lived, acetaldehyde is a highly toxic substance and known carcinogen which has the potential to cause significant damage, not only to the liver but also the pancreas, brain and along the GI tract where some alcohol metabolism also occurs. The tissue damage and inflammation caused by alcohol and its toxic byproducts can compromise nutrient digestion and metabolism, and over time lead to more serious health problems (Cederbaum, 2012).

Although alcohol is certainly not needed by the body in large (or any) amounts, it is considered its own class of macronutrient. Alcohol is metabolized differently than the other macronutrients and is energy-dense, containing 7 calories per gram (almost double that of carbs and protein, and second to fat in terms of energy density). In addition to its high calorie content, alcohol provides little in the way of nutrients and is therefore often considered “empty calories”.

Even though alcohol is not stored in the body, it affects the metabolism of other nutrients which can result in additional fat storage and body composition changes. Because it is so toxic, the body prioritizes the metabolism of alcohol over everything else until it’s completely burned off, which means the processing of carbs, fat and protein is put “on hold”. Only, “on hold” in the body signifies fat storage (Cederbaum, 2012). Since alcohol is frequently paired with the consumption of food and other drinks, these fat-storing effects are often further amplified. Drinking on an empty stomach, however, is not an effective alternative, as doing so leads to rapid gastric emptying and consequent increased state of inebriation, not to mention a whole host of unpleasant symptoms to look forward to including electrolyte imbalances, gastric irritation, hypoglycemia and sleep disturbances (Barnes, 2014).

It doesn’t help that alcohol has been shown to affect hormone production and secretion, particularly those involved in muscle growth. Researchers Haugvad et al. found an increase in cortisol production (which stimulates protein breakdown) and decrease in testosterone secretion (which stimulates protein synthesis) with high doses of alcohol. With frequent occurrence, these effects can negatively impact body composition and muscular adaptations to training stimuli.

All this being said, will a drink or two every now and then really throw off your training and performance goals? We wouldn’t say so. However, we also wouldn’t go around touting the health benefits of moderate alcohol consumption from epidemiological studies. These studies can’t draw “cause and effect” relationships, but rather associations, which means there’s a lot of potential confounding variables that can affect study outcomes. If you are going to drink, we recommend keeping consumption low and preferably post-training (rather than before). If you do choose to drink afterwards, it’s important to prioritize an alternative hydration option and some form of post-workout nutrition (carb and protein combo) first. We also highly recommend nonalcoholic beer, which is becoming increasingly popular within the athletic community, from companies like Athletic Brewing. Without the alcohol, beer contains some of the essentials for post-workout nutrition, including carbs and electrolytes.

References:

Barnes, M. J. (2014). Alcohol: Impact on sports performance and recovery in male athletes. Sports Medicine, 44(7), 909-919. https://doi.org/10.1007/s40279-014-0192-8

Cederbaum A. I. (2012). Alcohol metabolism. Clinics in liver disease, 16(4), 667-685. https://doi.org/10.1016/j.cld.2012.08.002

Haugvad, A., Haugvad, L., Hamarsland, H., & Paulsen, G. (2014). Ethanol does not delay muscle recovery but decreases testosterone/cortisol ratio. Medicine & Science in Sports & Exercise, 46(11), 2175-2183. https://doi.org/10.1249/mss.0000000000000339

Vella, L. D., & Cameron-Smith, D. (2010). Alcohol, athletic performance and recovery. Nutrients, 2(8), 781-789. https://doi.org/10.3390/nu2080781

Relative Energy Deficiency in Sport (RED-S)

Category:energy deficiency,fuel,nutrition,performance,self-care

Over the past few weeks, we have covered some of the basics of fueling in our discussion of macronutrients and micronutrients, as well as a deep dive into carbohydrates. Our hope is that the Yancy Camp Nutrition audience is well informed on the science behind the delicious food that fuels your workouts. This week’s topic is such an important topic and we hope you take the time to read it, even if you think it may not apply to you – it’s an important one!

Relative Energy Deficit in Sport (RED-S) was first introduced in 2014 by the IOC (International Olympic Committee), and an update was published in 2018 (Mountjoy et al, 2018). The IOC published a consensus statement titled “Beyond the Female Athlete Triad: Relative Energy Deficiency in Sport (RED-S).” This was an important update for healthcare professionals working with active individuals and the information continues to inform the work that we do on a daily basis – let’s break it down a little for you.

RED-S refers to the body’s impaired functioning caused by inadequate energy intake relative to the amount of fuel needed to perform normal body functioning, plus that required for physical activity. Just being alive, walking around, digesting your food, breathing, and daily body functioning requires fuel (even when you have a chill day, all day). This equates to resting metabolic rate (RMR). Additional fuel is needed for exercise. The fuel you eat needs to cover all of the energy demands of both. Your energy availability (EA) is the number you get when you subtract the energy that is needed to cover all physiological demands from that which you eat, and divide it by your lean mass. You don’t actually need to do this calculation (your Sports Dietitian will help you with that – it’s a pretty involved calculation), but it’s important to understand the concept of EA. When an athlete falls too far below a certain level of EA, the body responds by slowing down and preserving. It slows down the metabolic rate, it shuts down non-essential functioning (menstrual cycles), and more, such as bone health, immunity, protein synthesis and cardiovascular health.

In practice, I often work with female athletes that have lost their menstrual function for a portion of their lives, or were delayed in starting their periods. Often, these women may have been told – “its normal, you’re an athlete.” My response to this is – “it’s common but not normal.” Any time our body is delaying or shutting down a physiological function, it’s sending a signal that something is off. Losing menstrual function is just one sign of RED-S, and for men, it’s not a sign they can rely on. Therefore, it’s important to be aware of signs and symptoms.

Many of the athletes that I’ve worked with fall into RED-S unintentionally. The energy demands for their sport are very high, and hunger cues are blunted with high volumes and intensities of activity, making it difficult to keep up with caloric demands. Another risk factor is dieting or restricting intake to meet body composition or weight goals. It’s important to know that even a short time of restriction while energy demand remains high, can negatively impact hormones that can ultimately affect bone health.

There are various signs and symptoms that I will assess when working with athletes in order to identify the potential for RED-S. Some athletes that I work with struggle with feeling fatigued, or are unable to feel recovered no matter how much sleep they get or recovery work that they do. Some struggle with sleep disturbances, or gastrointestinal (stomach) issues such as irritable bowel syndrome, constipation or diarrhea. Others fight illness or injuries, such as bone stress injuries. Others struggle with adapting to their workouts and seeing performance improvements that they expect to see based on their written workout, and some can’t make changes to their body composition. They may have an eating disorder or disordered eating, making meeting calorie demands very stressful. As a Sports Dietitian, these are all things that need to be assessed to identify potential RED-S, and ultimately find ways to heal the metabolic rate and other affected physiological functions. If RED-S is suspected, we work closely with physicians who can assist with diagnostic testing, such as lab work.

If you think you may be at risk for RED-S, we recommend working with a Sports Dietitian or other licensed medical professional to work to heal and reach improved performance. If you’re unsure if you are at risk, but have a feeling you may be under-fueling, but aren’t sure what to change, please reach out to a qualified Sports Dietitian who can assess your intake in relation to your expenditure and then help come up with a plan that works individually for you! It’s important not to ignore the signs from your body. If left untreated for even short periods of time, the consequences of RED-S on health and performance can add up to long term issues.

References:

Mountjoy, M., Sundgot-Borgen, J. K., Burke, L. M., Ackerman, K. E., Blauwet, C., Constantini, N,…Budget, R. (2018). IOC consensus statement on relative energy deficiency in sport (RED-S): British Journal of Sports Medicine, 52(11), 687–697. http://doi.org/10.1136/bjsports-2018-099193

Keay, N. & Rankin, A. (2019). Infographic. Relative energy deficiency in sport: An infographic guide.. British Journal of Sports Medicine, 53,1307-1309. http://doi.org/10.1136/bjsports-2018-100354

Health4Performance. (2018). Relative energy deficiency in sport (RED-S). Retrieved from http:// health4performance.co.uk

Corinna Coffin, YCN Dietitian and OCR Athlete

Micronutrient Needs for Athletes

Category:fuel,Micronutrients,nutrition,performance

In our previous blog post, we discussed the increased macronutrient needs of athletes and active individuals and why these are so important – from increased performance outcomes to injury prevention and recovery among many others. The macronutrients (protein, carbs and fat) often take the spotlight when it comes to nutrition; after all, they are required by the body in the largest amount. However, of equal (if not more) importance are the micronutrients provided by the various protein, fat and carbohydrate options we have to choose from on a daily basis.

Micronutrients are the nutrients the body requires in relatively small (“micro”) amounts which include vitamins and minerals. They play an essential role in the body, particularly when it comes to regulating processes such as energy production and the manufacturing of new cells and proteins (Maughan, et al., 2018). Micronutrient deficiencies can impair sports performance (and overall health) in a variety of ways, such as increasing an individual’s risk of illness or injury, or impacting his or her ability to train effectively. The metabolic and biochemical adaptations which occur during exercise, as well as increased nutrient turnover and/or loss, increase the need for certain nutrients in active individuals and athletes. Micronutrients of frequent sub-optimal consumption and therefore of key interest to athletes and active individuals include iron, vitamin D, calcium and antioxidants (Maughan, et al., 2018).

Iron is an important component of red blood cells and is necessary to transport oxygen to our muscles. Iron deficiency can negatively impact physical and mental performance, as well as overall health (Volpe, et al., 2015) . Limited iron intake, poor bioavailability and/or inadequate energy intake are all risk factors for iron deficiency. Athletes who experience menstrual blood loss, foot-strike hemolysis (the rupture of red blood cells due to repetitive pounding on hard surfaces), excess losses in sweat, urine or feces and/or train at high altitude often have increased iron needs (Cowell et al., 2003). Female distance runners and vegetarians who may not be getting sufficient amounts of iron (particularly heme iron from animal sources) through their diet are at greatest risk for iron deficiency (Cowell et al., 2003). Oral supplementation can certainly be an effective solution for those with iron deficiency anemia; however, athletes and individuals concerned about iron status can adopt eating strategies to help ensure sufficient levels, such as consuming red meat, poultry, shellfish and organ meats. For athletes who abstain from meat consumption, vitamin C should be paired with plant-based iron sources such as beans/legumes, spinach and quinoa, as it aids in the absorption process (Thomas et al., 2016). At-risk athletes for iron deficiency should be regularly screened and aim for a daily iron intake above the Recommended Dietary Allowance (RDA) of 18mg for women, 8mg for men (Cowell et al., 2003).

Vitamin D is an essential micronutrient for athletes in particular due to its important role in maintaining bone health and regulating the minerals calcium and phosphorus. Sufficient vitamin D status has been linked to decreased risk of stress fractures, acute respiratory illness and inflammation among others (Pojednic & Ceglia, 2014). Individuals who get plenty of sunshine and train mostly outdoors are at lower risk for vitamin D insufficiency compared to those with limited sun exposure; however, other factors such as skin tone, fat mass, training time, and clothing/equipment interfering with UVB exposure can alter risk for deficiency (Cannell et al., 2009). Dietary sources of vitamin D include fatty fish, beef liver, egg yolks, cheese, some fortified dairy and cereal products, and mushrooms; however, as a fat soluble vitamin, a fat source is required for optimal absorption. Unfortunately, dietary interventions alone have shown to be unreliable in resolving insufficiencies. Therefore, responsible UVB exposure and supplementation may be necessary to maintain sufficient status. Active individuals prone to stress fractures and other bone/joint injuries or with signs of overtraining, muscle pain or weakness and low sun exposure may require professional assessment to determine if vitamin D supplementation is necessary (Moran et al., 2013).

Calcium plays an integral role in the growth, maintenance and repair of bone tissue, as well as muscle contraction, nerve conduction, and blood clotting. Individuals more susceptible to suboptimal calcium status tend to be those who restrict energy intake, display patterns of disordered eating, and/or avoid dairy products, putting them at greater risk for deficiency (Thomas et al., 2016). Foods high in calcium include dairy products such as milk, yogurt and cheese, as well as non-dairy options such as beans and lentils, almonds, dark leafy greens and figs. It’s important to note that even with sufficient calcium intake, vitamin D is essential for its absorption within the body, emphasizing the need for both nutrients.

Even though physical activity is considered a key component of stress management and stress relief, exercise still creates internal stress within our bodies. When we engage in aerobic (requiring oxygen) exercise, our oxygen consumption increases significantly compared to rest. As a byproduct of this aerobic metabolism, reactive oxygen species (ROS) are produced. In relatively low amounts, such as with acute exercise and low-grade stress, ROS are beneficial to our health and play an essential role in the development and optimal functioning of every cell in our body (Thomas et al., 2016). Chronic stress (including chronic exercise-induced stress), however, can cause elevated intracellular levels of ROS and lead to oxidative stress. Oxidative stress occurs when there is a shift in the balance between oxidants and antioxidants in the favor of oxidants (Peternelj, et al., 2011). Antioxidants have the ability to attenuate the damaging effects of ROS. Our bodies generate their own antioxidant defenses; however, antioxidants are also found in food, especially fruits, vegetables and other plant-based whole foods. The safest and most effective strategy to increase antioxidant levels in the body is to consume a varied diet high in antioxidant-rich plant foods, such as berries, dark chocolate, green tea, kale, spinach, beans and nuts (Peternelj, et al., 2011). Individuals at greatest risk for low antioxidant intakes are those who restrict energy intake, follow a chronically low-fat diet, or limit intake of carbohydrates such as fruits, vegetables and whole grains (Thomas et al., 2016). Current research does not support the use of antioxidant supplementation as a means of combating exercise-induced oxidative stress, as high antioxidant doses have been shown to interfere with the positive effects of exercise and training-induced adaptations (Peternelj, et al., 2011).

It’s important to note that while these micronutrient considerations provide a fundamental framework for athletes, nutrition needs vary based on the individual. Additionally, individuals with dietary limitations and/or avoidances may have increased micronutrient concerns. We recommend consulting with a registered dietitian to ensure adequate nutrient needs are being met in support of the demands of training and competition.

References:

Cannell, J.J., Hollis, B.W., Sorenson, M.B., Taft, T.N., & Anderson, J.J. (2009). Athletic performance and vitamin D. Medicine & Science in Sports & Exercise,41(5), 1102-1110.

Cowell, B.S., Rosenbloom, C.A., Skinner, R., Summers, S.H. (2003). Policies on screening female athletes for iron deficiency in NCAA division I-A institutions. International Journal of Sport Nutrition and Exercise Metabolism,13(3), 277-285.

Maughan, R. J., Burke, L. M., Dvorak, J., Larson-Meyer, D. E., Peeling, P., Phillips, S. M., Engebretsen, L. (2018). IOC Consensus statement: Dietary supplements and the high-performance athlete. International Journal of Sport Nutrition and Exercise Metabolism, 28(2), 104-125. http://doi.org/10.1123/ijsnem.2018-0020

Moran, D. S., McClung, J. P., Kohen, T., Lieberman, H. R. (2013). Vitamin D and physical performance. Sports Medicine, 43(7), 601-611.

Peternelj, T. T., Coombes, J.S. (2011). Antioxidant supplementation during exercise training: Beneficial or detrimental? Sports Medicine, 41(12), 1043-1069.

Pojednic, R. M., Ceglia, L. (2014). The emerging biomolecular role of vitamin D in skeletal muscle. Exercise & Sport Sciences Reviews. 42(2), 76-81.

Thomas, D. T., Erdman, K. A., & Burke, L. M. (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance. Journal of the Academy of Nutrition & Dietetics,16, 501-528. http://doi.org/0.1016/j.jand.2015.12.006

Volpe, S. L., Bland, E. (2012). Vitamins, minerals, and exercise. In Rosenbloom, C. A. & Coleman, E. J. (Eds.). Sports nutrition: A practice manual for professionals (5th ed.), (pp. 75-105). Chicago, Illinois: Academy of Nutrition and Dietetics.

Corinna Coffin, YCN Dietitian & OCR Athlete

Macronutrient Needs For Athletes

Category:fuel,macronutrients,nutrition,performance

Nutrition recommendations for athletes and active individuals differ from their sedentary counterparts. The use of nutrition has become widespread in various disciplines as a means of improving performance, fitness, and overall health (Steinmuller et al., 2014). There is a growing body of evidence suggesting that specific dietary practices may increase peak performance potential of an individual; thus, appropriate sports nutrition practices may greatly benefit athletes and allow them to further excel in their sport (Hull et al., 2016; Thomas et al., 2016). Appropriate nutrient intake from food and fluid is crucial to fuel metabolic mechanisms and other bodily processes. Nutrient requirements will vary depending upon the training regimen and other external factors that may decrease or increase an individual’s nutrient needs.

MACRONUTRIENT NEEDS:

Let’s start by addressing the macronutrients. Macronutrients are the nutrients the body requires in relatively large (“macro”) quantities which include protein, fat and carbohydrates. Adequate consumption of carbohydrates is required for active individuals in particular because of the role they play in metabolism before, during, and after an exercise session. Carbohydrates are the predominant fuel source for the brain and central nervous system, as well as a substrate for muscular work (Thomas et al., 2016). Therefore, due to limited body carbohydrate stores and rapid depletion, athletes and active individuals require sustained intake of exogenous (that which we take in) carbohydrates through their diet. Another important component of consuming adequate carbohydrates is their protein-sparing effects. If energy intake (particularly from carbohydrate) is inadequate to meet the demands of the body, amino acids (the building blocks of protein) are oxidized for fuel rather than protein synthesis (Thomas et al., 2016).

Active individuals have increased protein needs to maximize metabolic adaptation to training through the repair and anabolism (or growth) of skeletal muscle. Daily protein requirements generally range from 1.2 to 2.0 g/kg bodyweight spread out in moderate amounts over the course of the day and following strenuous training sessions (Moore et al., 2015). In the past, these general daily ranges were categorized for individuals depending on sport – strength athletes’ needs would be toward the higher end while endurance athletes’ needs were lower – however, this is no longer the case. Newer guidelines recommend protein intake be based around adaptation to training sessions within a periodized program, while also considering the individual’s athletic goals, nutrient and energy needs, and available food choices (Moore et al., 2015). Due to the protein-sparing effects of carbohydrates, adequate energy intake (specifically from carbohydrates) is an important consideration for determining protein needs. In cases of energy restriction, increased protein intake of 2.0 g/kg/day or higher may be advantageous to prevent the loss of lean body mass (Rodriguez et al., 2007).

Dietary fat is an important, yet often misunderstood and overlooked, component of the diet for both active and sedentary individuals. Not only does fat provide us with sustained energy as a fuel substrate, it is essential for the absorption of fat-soluble vitamins and contains essential components for cellular membranes (Thomas et al., 2016). Although dietary fat (lipid) needs are not directly increased in athletes to support sport performance, fat is calorically dense; therefore, it is likely that an athlete’s lipid needs would proportionally increase to meet increased caloric needs. Fat intake below 20% of total daily energy intake is discouraged, as this limits intake of fat-soluble vitamins and essential fatty acids integral to our health (Thomas et al., 2016). Instead, only acute scenarios of fat restriction should be implemented leading up to an event, training session and/or during pre-event carbohydrate loading.

It’s important to note that while these macronutrient considerations provide a fundamental framework for athletes, nutrition needs vary based on the individual. For example, vegetarian athletes and those with dietary limitations may have additional macronutrient concerns and may benefit from a more comprehensive dietary analysis and nutrition education (Craig & Mangels, 2009). We recommend consulting with a registered dietitian to ensure adequate nutrient needs are being met in support of the demands of training and competition.

Stay tuned for next week’s informative blog on Micronutrient Needs for Athletes.

References

Craig, W. J., & Mangels, A. R. (2009). American Dietetic Association. Position of the American Dietetic Association: Vegetarian diets. Journal of the American Dietetic Association, 109(7),1266-1282.

Hull, M. V., Jagim, A. R., Oliver, J. M., Greenwood, M., Busteed, D. R., & Jones, M.T. (2016). Gender differences and access to a sports dietitian influence dietary habits of collegiate athletes. Journal of International Society of Sports Nutrition,13, 38. https://doi.org/10.1186/s12970-016-0149-4

Moore, D. R., Phillips, S. M., & Slater, G. (2015). Protein. In V. Deakin & L. Burke (Eds.) Clinical sports nutrition (5th ed.), (pp. 94-113). Sydney, Australia: McGraw-Hill Education.

Rodriguez, N. R., Vislocky, L. M., & Gaine, P. C. (2007). Dietary protein, endurance exercise, and human skeletal-muscle protein turnover. Current Opinion in Clinical Nutrition & Metabolic Care, 10(1), 40-45.

Steinmuller, P. L., Kruskall, L. J., Karpinski, C. A., Manore, M. M., Macedonio, M.A., & Meyer, N. L. (2014). Academy of Nutrition and Dietetics: Revised 2014 standards of practice and standards of professional performance for registered dietitian nutritionists (competent, proficient, and expert) in sports nutrition and dietetics. Journal of the Academy of Nutrition & Dietetics, 114, 631-641.

Thomas, D. T., Erdman, K. A., & Burke, L. M. (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance. Journal of the Academy of Nutrition & Dietetics,16, 501-528. http://doi.org/10.1016/j.jand.2015.12.006.

Simple vs. Complex Carbs: What’s the Difference, When to Consume Each & Pre-workout Fueling Strategies

Category:carbohydrates,fuel,nutrition,performance

Carbohydrates are an essential component of the diet, particularly for athletes, as they provide our muscles with the energy needed to function correctly (contract) and perform optimally for strength and endurance. Today, confusion over carbs exists because of conflicting information: current fad diets give carbohydrates a bad rap, and food manufacturers reign with producing and successfully marketing more and more calorie-dense, nutrient-deficient processed and refined food products. Fortunately, we are here to break it down for you, and help you understand what you need to know to make the best decisions for your health and performance.

Carbohydrates are often divided into two main groups: simple and complex. These terms are used to refer to the speed of digestion and absorption of nutrients by the body. “Simple” carbs are digested and absorbed relatively quickly compared to “complex” carbs, which take more time to be processed. You’re probably wondering what components increase or decrease the time it takes for a carbohydrate-rich food to be digested and absorbed. Good question! This depends on the fiber, starch and sugar content of the carbohydrate.

Simple carbs

Let’s start with sugar. Table sugar, scientifically known as sucrose, is a disaccharide (“di” = two, “saccharide” = sugar), meaning it is composed of 2 sugar molecules: glucose and fructose. Glucose and fructose (and galactose) are considered monosaccharides (single sugar units), which are in their simplest form, and can’t be broken down any further by the body. Since table sugar (sucrose) only needs to be split once to be used for energy, it makes sense that foods with higher amounts of sugar take less time to process and therefore fall into the “simple” category. Simple carbs elicit an insulin response, which stimulates the uptake of sugar into our cells in order to be used for energy. These types of carbohydrates are beneficial in situations where you’re about to start some form of physical activity and need quick fuel, or in the middle of a long and/or intense activity and need something to sustain energy levels even further. Simple carbs are also great for post-activity/training in order to replenish carbohydrate stores that were lost and to promote muscle recovery. With less activity or when mostly sedentary, the body is not in need of instant energy from simple carbohydrates, so this is a good time to focus on complex carbohydrates.

“These types of (simple) carbohydrates are beneficial in situations where you’re about to start some form of physical activity and need quick fuel”

Complex carbs

Switching over to complex carbohydrates, this is where fiber and starch come into play. Fiber is the structural component of plants (think cell walls), and is a non-digestible polysaccharide (many sugar units). This means the breakdown process requires more effort (and is more “complex”) since there are numerous sugar units that need to be broken down into simple sugars. High fiber foods are more filling, because food stays in your stomach longer due to the complexity of the digestive process. When our food digests quickly as we eat (such is the case with simple carbs), we inevitably are able to eat more, which is why it’s so easy to over-consume candy, cookies, soda, juice and other treats. Starch is a polysaccharide that can be digested by the body, and is found in some of the same foods as fiber. Potatoes are a good example of starchy carbohydrates, although they do contain fiber in the skin. Due to the longer chains of sugars, starches are also considered complex. Aside from pre, during and post workout fuel/snacks, most of our carbohydrate intake should be from complex sources in order to provide us with slower-releasing, sustained energy throughout the day.

Examples of simple carbs

Now that you know the difference between simple and complex carbohydrates and the types of scenarios in which it’s best to consume each, let’s talk about which foods belong in each category! When it comes to simple carbohydrate options, it’s important to understand that there are many whole foods that contain natural sugars, so foods with lots of added sugars (like candy and cookies) aren’t necessary to provide us with the benefits of rapid energy. For example, foods like yogurt, milk and fruit juice contain natural sugars. Other simple carb foods include breads and pastas (made with refined white flour), most breakfast cereals, honey, jams, soda, crackers, cookies, cakes, candies and other ‘treats’.

Examples of complex carbs

While highly processed, nutrient-poor complex carbohydrates do exist, this is much less common compared to simple carbs. The majority of complex carbs come to us in the form of whole grains such as barley, oats, rice, quinoa and corn, as well as whole grain products like pastas, breads, crackers etc. Other complex carbohydrates include vegetables, beans/legumes, nuts and seeds.

What about fruit?

Fruits are somewhat tricky to classify between simple and complex carbohydrate groups because they contain sugar AND fiber. However, depending on the fruit, the sugar to fiber ratio can be very high, in which case, it would act more like a simple carb. This includes fruits such as bananas, mangoes and pineapple. On the other hand, fruits that are naturally lower in sugar but high in fiber, such as berries and pears, can be considered more “complex” than “simple”. Think of this classification as a spectrum rather than linear with absolutes as many foods share components of each.

Fiber additives + supplements

In today’s world of refined and fortified foods/food products, there are now “functional fibers”, which may be extracted from natural sources or made in a lab, that are used to fortify foods that don’t normally contain fiber (for example: “fibered up”Splenda). This allows companies to claim that their products are “healthy” when really they contain very little nutrition. Extracted natural fibers include lignin, cellulose, pectin, gum, and psyllium. On that note, let’s talk about fiber supplementation for a minute, such as popular brands like Metamucil, Benefiber and Citrucel. While we aren’t necessarily anti-fiber supplementation, the amount of naturally-occurring fiber in our diet tells us a lot about the quality of carbohydrate we are consuming, and if this is low, it would best serve you to try to increase that number by opting for more unprocessed, unrefined whole foods like fruits, vegetables, beans, nuts, seeds and whole grains. Additionally, fiber additives and supplements can cause GI distress, and should not be relied upon for normal GI functioning. We recommend talking with a dietitian or doctor if this is the case for you.

Pre-workout fueling

It only makes sense to discuss pre-workout fueling strategies now that we’ve discussed the different types of carbohydrates, since carbs are the primary focus leading up to a training session or event. Depending on the timing, this can mean a larger focus on complex carbs or simple carbs. For most big meals leading up to an event or training session, there should be an emphasis on complex carbs so long as the event is not for another 3-4 hours giving your body time to properly digest. This can include options such as oatmeal, bagels, and whole wheat bread with fruit. Lighter meals/snacks consumed within 2 hours of an event or training session should contain mostly simple carbs, and anything within an hour of go-time should contain simple carbs ideally in the form of liquids or gels to serve as readily available fuel and decrease GI distress during physical activity. Pre-workout simple carb options can include cereal with milk, jam on toast, pretzels, raisins (or dried fruit) and granola bars. Sports drinks, fruit pouches, carbohydrate mixes, energy gels and chews are best in close proximity to your event/training.

Final thoughts

Hopefully you have a much better understanding of simple vs complex carbohydrates and understand the roles of each for your health and performance. Understand that these labels aren’t mutually exclusive; food is complex (for lack of a better word), so it can help to think of “simple” and “complex” carbs more like a spectrum rather than two distinct groups. There are simple carbs that provide us with lots of great nutrition, and others that are essentially void of nutrients. There are also some forms of simple carbs that are healthier than some complex carbs, so it’s important to consider the overall nutrient profile of a food particularly when making decisions to support a healthy diet. Lastly, keep in mind there’s a time and a place for everything – even foods you may consider empty calories – such as ‘fun foods’ like cookies or birthday cake. Those foods should be included for overall enjoyment of your diet. Not all foods need to have a physical function – some are okay to fuel the soul. The goal is to be mindful of frequency.

Nutrition & Athletic Performance: How Food Impacts Our Physical Output

Category:fuel,nutrition,performance

Hi everyone! Welcome to our first post on the Yancy Camp Nutrition blog! We are so excited to be able to offer a nutrition component of Yancy Camp, as nutrition is such a critical part of the health and performance equation. What better way to kick off our blog series than to start by discussing this important role. After all, we know you all devote a great deal of time and energy to your training; it only makes sense to ensure you’re reaping ALL the benefits of your hard work.

If you’re working through Yancy Camp for your OCR training (as most of you reading this likely are), you have made a conscious effort to seek out and implement an effective training regimen each day to help you achieve your goals. And because you have your training all laid out for you, you are very likely to succeed. But what about nutrition? Do you put the same kind of effort and attention into the food and meals you eat each day as you do your workouts? This might seem like a strange concept to you, but if you think about it, our encounters with food are far more frequent throughout the day than the time we spend running or lifting heavy objects. If we didn’t have a game plan for our workouts each day and had to come up with them on the spot, we likely wouldn’t accomplish as much as we otherwise could were it all planned out. Similarly with nutrition, our food choices are likely to be poorer when we wait until the last minute to decide what to eat rather than plan ahead. If we compound this cycle of deciding what to eat until the last minute, day after day, week after week, month after month, it is likely to presume our health will take a serious toll.

So planning out your day (to some extent) nutritionally is important- got it! But what should you focus on specifically and how do you implement it? As an Elite Obstacle Course Racer with more than 6 years of competitive racing under my belt and 9+ years of studying nutrition & dietetics, the combination and implementation of nutrition for health and performance has been a huge focus of mine. But I had to come to terms with a difficult notion, which took some time to learn and accept: eating for health and performance versus solely for health can look very different. This does not mean the two are completely different entities and share no overlap, as this is not the case. However, we are often so quick to implement the latest nutritional research claiming improved health and longevity without considering the repercussions on our physical performance. That being said, if you are seeking a competitive edge in any physical endeavor, there are a few critical nutrition components that may change your outlook on performance nutrition and help take you to the next level:

Calories = Fuel, Fuel = Output. Calorie restriction? Fasting? Low-carb diets? There may be a time and place for these things, but race season (or any time when peak performance is desired) is not one of them. We will discuss nutrient timing later (which is different), but simply put, we cannot ask our bodies for exceptional output if our input is below our needs. If you are a competitive athlete, ideally, over the course of a year, you will have periods of time when you want to peak for certain races or events and other times when you’re further out from competitions when performance is less important. Any weight loss efforts should occur during these non-peak periods of time so as not to interfere with performance outcomes.

Consider your fuel substrate. The intensity at which we are exercising dictates whether we are utilizing mostly fat or carbs as our primary substrate. Due to the oxygen content, we utilize mostly carbohydrates at higher intensities, especially when we are anaerobic (or “without oxygen”), as the oxygen in the molecular structure of carbs makes up for the lack of oxygen we are getting into our body and to our muscles at higher intensities. Conversely, at lower intensities, we are getting plenty of oxygen to be able to utilize fat as the primary fuel source. With this understanding, it makes sense why a higher intake of carbohydrates is necessary to achieve high intensities.

Nutrient timing: pre-workout. Understanding your primary fuel substrate during exercise leads us to proper nutrient timing. If we wish to perform a high intensity in our training or competition, it is important to supply our body with sufficient carbohydrates beforehand. Our muscles can store a finite amount of carbohydrates (~400 g), after which we can tap into our liver glycogen (the storage form of carbs; ~100 g) before being completely depleted. Since these stores are rarely “topped off”, it’s important to fuel with carbohydrates beforehand.

Nutrient timing: post-workout. Once we finish a workout, we have depleted our muscle (and potentially our liver) glycogen stores to some capacity, depending on the intensity and duration of our workout. In order to minimize muscle soreness and maximize recovery, replenishing these carbohydrate stores is essential. If you work out earlier in the day, chances are you will consume a sufficient amount of carbs over the course of the day to replenish what was lost. However, consuming some carbohydrates shortly after a workout, particularly a simple, fast-digesting source (eg. a banana, ), enables these key nutrients to get to our muscles much quicker, as our cells are more sensitive (ie. receptive) to carbohydrates during this time.

Of course, these are only a handful of key nutrition principles to consider when it comes to improving physical performance; however, we will expand upon these further in a later post. In the meantime, we encourage you to take a deeper dive into your own nutrition to see it may be affecting your performance, for better or worse. Our Yancy Camp Nutrition team is committed to helping you achieve the health and fitness goals you’ve set out to accomplish, and would love to hear from you with any questions or comments. As always, we invite you to contact us directly or schedule a consult with one of our dietitians today!

Category Archives: performance

References:

Burke, L. M., Loon, L. J., & Hawley, J. A. (2017). Postexercise muscle glycogen resynthesis in humans. Journal of Applied Physiology,122(5), 1055-1067. https://doi.org/10.1152/japplphysiol.00860.2016

Yeo, S. E., Jentjens, R. L., Wallis, G. A., & Jeukendrup, A. E. (2005). Caffeine increases exogenous carbohydrate oxidation during exercise. Journal of Applied Physiology,99(3), 844-850. https://doi.org/10.1152/japplphysiol.00170.2005

References:

Burke, L. M., Hawley, J. A., Wong, S. H. S., & Jeukendrup, A. E. (2011): Carbohydrates for training and competition, Journal of Sports Sciences, 29:sup1, S17-S27 http://dx.doi.org/10.1080/02640414.2011.585473

Michalczyk, M., Chycki, J., Zajac, A., Maszczyk, A., Zydek, G., & Langfort, J. (2019). Anaerobic performance after a low-carbohydrate diet (LCD) followed by 7 days of carbohydrate loading in male basketball players. Nutrients,11(4), 778. http://doi.org/10.3390/nu11040778

References:

Barnes, M. J. (2014). Alcohol: Impact on sports performance and recovery in male athletes. Sports Medicine, 44(7), 909-919. https://doi.org/10.1007/s40279-014-0192-8

Cederbaum A. I. (2012). Alcohol metabolism. Clinics in liver disease, 16(4), 667-685. https://doi.org/10.1016/j.cld.2012.08.002

Haugvad, A., Haugvad, L., Hamarsland, H., & Paulsen, G. (2014). Ethanol does not delay muscle recovery but decreases testosterone/cortisol ratio. Medicine & Science in Sports & Exercise, 46(11), 2175-2183. https://doi.org/10.1249/mss.0000000000000339

Vella, L. D., & Cameron-Smith, D. (2010). Alcohol, athletic performance and recovery. Nutrients, 2(8), 781-789. https://doi.org/10.3390/nu2080781

References:

Mountjoy, M., Sundgot-Borgen, J. K., Burke, L. M., Ackerman, K. E., Blauwet, C., Constantini, N,…Budget, R. (2018). IOC consensus statement on relative energy deficiency in sport (RED-S): British Journal of Sports Medicine, 52(11), 687–697. http://doi.org/10.1136/bjsports-2018-099193

Keay, N. & Rankin, A. (2019). Infographic. Relative energy deficiency in sport: An infographic guide.. British Journal of Sports Medicine, 53,1307-1309. http://doi.org/10.1136/bjsports-2018-100354

Health4Performance. (2018). Relative energy deficiency in sport (RED-S). Retrieved from http:// health4performance.co.uk

References:

Cannell, J.J., Hollis, B.W., Sorenson, M.B., Taft, T.N., & Anderson, J.J. (2009). Athletic performance and vitamin D. Medicine & Science in Sports & Exercise,41(5), 1102-1110.

Cowell, B.S., Rosenbloom, C.A., Skinner, R., Summers, S.H. (2003). Policies on screening female athletes for iron deficiency in NCAA division I-A institutions. International Journal of Sport Nutrition and Exercise Metabolism,13(3), 277-285.

Moran, D. S., McClung, J. P., Kohen, T., Lieberman, H. R. (2013). Vitamin D and physical performance. Sports Medicine, 43(7), 601-611.

Peternelj, T. T., Coombes, J.S. (2011). Antioxidant supplementation during exercise training: Beneficial or detrimental? Sports Medicine, 41(12), 1043-1069.

Pojednic, R. M., Ceglia, L. (2014). The emerging biomolecular role of vitamin D in skeletal muscle. Exercise & Sport Sciences Reviews. 42(2), 76-81.

Volpe, S. L., Bland, E. (2012). Vitamins, minerals, and exercise. In Rosenbloom, C. A. & Coleman, E. J. (Eds.). Sports nutrition: A practice manual for professionals (5th ed.), (pp. 75-105). Chicago, Illinois: Academy of Nutrition and Dietetics.

References

Craig, W. J., & Mangels, A. R. (2009). American Dietetic Association. Position of the American Dietetic Association: Vegetarian diets. Journal of the American Dietetic Association, 109(7),1266-1282.

Hull, M. V., Jagim, A. R., Oliver, J. M., Greenwood, M., Busteed, D. R., & Jones, M.T. (2016). Gender differences and access to a sports dietitian influence dietary habits of collegiate athletes. Journal of International Society of Sports Nutrition,13, 38. https://doi.org/10.1186/s12970-016-0149-4

Moore, D. R., Phillips, S. M., & Slater, G. (2015). Protein. In V. Deakin & L. Burke (Eds.) Clinical sports nutrition (5th ed.), (pp. 94-113). Sydney, Australia: McGraw-Hill Education.

Rodriguez, N. R., Vislocky, L. M., & Gaine, P. C. (2007). Dietary protein, endurance exercise, and human skeletal-muscle protein turnover. Current Opinion in Clinical Nutrition & Metabolic Care, 10(1), 40-45.

“These types of (simple) carbohydrates are beneficial in situations where you’re about to start some form of physical activity and need quick fuel”

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