Sport-specific nutrition

The bottom layer of the pyramid (basic nutrition) is important for all athletes and is the foundation for an optimal nutrition. When basic nutrition (the basic diet) is not sufficient for an athlete and supplementation is needed, the middle layer of the pyramid should be taken into consideration: sport-specific nutrition. Sport-specific nutrition entails a dietary regime that will aid in optimizing sports performance. You can consider food products such as sports drinks, sports bars, sports gels and protein shakes, but in most cases basic nutrition products are just as good (or sometimes better). The top of the nutrition pyramid, sports supplements, can be beneficial when an athlete’s basic nutrition and sport-specific nutrition have been optimized. This document is about the middle layer of the nutrition pyramid.

1. Start with the basics Research concerning well-trained Dutch athletes showed that the basic dietary pattern of many of them was suboptimal. This results in a potential deficiency of A, B1, B2 and D. The studied athletes who did not use sport-specific nutrition (sports bars, sports gels, sports drinks, etc., to which vitamins and minerals were often added), additionally ran a small chance of a deficiency of vitamins B3 and C, and of the Selenium. Well- trained female athletes of child-bearing age also ran a risk of an iron deficiency (Wardernaar, et al., 2017). For athletes who avoid certain food groups (such as meat and dairy), for example vegetarians and vegans, it is important to monitor that they ingest enough B2, B12, D, and the minerals calcium, iron and zinc. If you wonder whether you consume sufficient nutrients, you could monitor your food intake for 3 days (an exercise day, a non-exercise weekday and a weekend day) to a whole week. See the document “Basic nutrition” for more information.

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2. Which criteria should you meet before sports-specific foods become necessary? Sport-specific nutrition entails all nutrition and nutritional regimes that can enhance sports performance. The type, intensity and duration of the exertion determine whether sports-specific foods could be beneficial in your situation. In this document athletes are classified in three groups, but sport-specific nutrition can only be optimal if it is tailored to the individual athlete. The 3 classes are: . Recreational athlete: An athlete who exercises up to 3 hours a week . Competitive athlete: An athlete who exercises between 3 and 6 hours a week . Professional athlete: An athlete with a top-level status

Recreational athlete On training and game days, the recreational athlete needs slightly more energy and fluids (Wardenaar, et al., 2014). The energy expenditure can be calculated by multiplying the Basal Metabolic Rate (BMR) with the Personal Activity Level (PAL). See the document “Basic nutrition” for a more detailed explanation. For exertions shorter than 1 hour, is sufficient to cover the fluid requirements (Wardenaar, et al., 2014). An isotonic thirst quencher1 can be appropriate when the exertion lasts longer than 1 hour.

Competitive athlete In addition to the guidelines for a recreational athlete, a competitive athlete requires more energy in the form of and proteins (Academy of Nutrition and Dietetics, Dietitians of Canada & The American College of Sports Medicine, 2016). The exact requirement depends on the duration and intensity of the bouts of exercise in the training program. For challenging trainings and competitions longer than 1 hour in duration you need an isotonic drink. Water is sufficient for training sessions less than 1 hour in duration.

Professional athlete In addition to the guidelines for a competitive athlete, a professional athlete requires considerably more energy in the form of carbohydrates and proteins as a professional athlete (Academy of Nutrition and Dietetics, Dietitians of Canada & The American College of Sports Medicine, 2016). A general advice is: 1 liter of an isotonic drink per hour, if you do not consume any other form of carbohydrates outside the isotonic drink.

1 An Isotonic (thirst quencher) contains 4-8% carbohydrate (4-8 gram of carbs per 100 ml). An isotonic drink has the same osmolality as blood. This means that an isotonic drink contains an equal number of particles as blood does. Because of this, an isotonic sports drink is easy to absorb during exercise and it diminishes the chance of gastrointestinal distress (McArdle, Katch, & Katch, 2015). Examples: , Isostar, lemonade (ratio of syrup and water 1 : 8-10, depending on the amount of carbohydrates in the syrup in question), (orange/apple) juice mixed with water until the right carbohydrate-water ratio. For homemade isotonic drinks, add some salt to supplement the loss of body salts.

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Hydration during and around exercise The general guidelines to consume 150-350 ml of water every 15-20 minutes during exercise and to replenish 150% of fluid loss after exercise are applicable to recreational athletes, competitive athletes and top athletes (Burke & Deakin, Clinical sports nutrition, 2015). Dehydration/hypohydration (but also overhydration/hyper- hydration) can have a negative effect on your health and sports performance. The amount you need to drink during exercise to avoid a decrease in sports performance is highly dependent on the individual athlete (Ayotte & Corcoran, 2018) (Goulet & Hoffman, 2019) (Hoffman, Cotter, Coulet, & Laursen, 2016). The amount of lost body fluid during exercise can be determined by weighing yourself before and after exercise. In any case: start well hydrated (Goulet, Performance Effects of Dehydration, 2013); make sure that your urine is light yellow in colour and doesn’t have a strong odor prior to training or competition.

3. The type, intensity and duration of the exertion determines the nutrient requirements In this document a distinction is made between strength training and endurance training. Of course, you can subdivide this into specific sports (e.g. game/team sports such as soccer, rugby, rowing and boxing), but this document will not go into that much detail. As a player of game sports (combination of strength and endurance sports) you can fall (to varying degrees) in both categories. Keep this in mind when you adjust your nutrition plan. In strength sports there is an emphasis on the intake of sufficient protein, to stimulate muscle protein synthesis (Phillips & Van Loon, 2011). In endurance sports there is an emphasis on the intake of carbohydrates, to restore depleted glycogen reserves.

Strength sports It is often said that the duration of an optimal strength training session does not last longer than 1 hour (Lewis- McCormick, 2012). It should be mentioned that this is not set in stone. The optimal duration has to do with, among other things, the type of training/sports (e.g., bodybuilding, power lifting, weightlifting, crossfit, strongman training, etc.), the degree of training experience and the training intensity (for example, how much rest you take between sets). In this document, the advice given is based on a training session of approximately one hour.

 Prior to exercise, the basic nutrition is sufficient to provide the energy you need during the bout of exercise. As a strength athlete you have a (slight) increased energy requirement (BMR x PAL), partially made up of an increased protein requirement (see Table 1).

Table 1: Protein requirements for strength athletes Source Strength sports (proteins in g/kg/day) Phillips & Van Loon (2011) 1.3-1.8* International Society of Sport-specific nutrition (2017) 1.2-2.0* Morton, et al. (2018) ~ 1.6* * = +20% for vegetarians who scarcely eat animal products, +30% for vegans (Health Council of the Netherlands, 2001)

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◦ Based on a requirement of 1.6 g of protein per kg of body weight, a good distribution of protein intake could be: 0.4 g of protein per kg body weight per meal, based on 4 (main) meals a day (Schoenfeld & Aragon, 2018). In practice, depending on your body weight of course, it often comes down to a portion of 20-30 g of protein per meal. The most optimal distribution, however, depends on a multitude of factors, such as time, practical options, personal preference for a certain meal frequency and social expectations/ circumstances. Find what is optimal within the recommendations, but is still sustainable for your personal situation.

 During exercise, fluids in the form of water will generally suffice. The glycogen stores are not depleted during a 1-hour strength training session (except maybe during intensive circuit training and crossfit workouts).

 After exercise, supplementing protein and fluids, with or without some carbohydrates, is recommended to promote recovery (Academy of Nutrition and Dietetics, Dietitians of Canada & The American College of Sports Medicine, 2016). A few examples: - Protein shake: whey protein2 (20 - 30 g protein) mixed with water or milk - Pea protein3 (20-30 g protein) mixed with water or a plant-based beverage (e.g. almond, oat or soy drink) - Low- cottage cheese or skyr with fruit and/or honey/ and fluids (water) - Cottage cheese with fruit and fluids (water) - Sandwiches with lean meat and a glass of milk - Sandwiches with egg and fluids (water) - Large portion of soy yogurt/soy quark This meal/snack is part of your total energy intake for that day.

Endurance sports With endurance training, there is a huge range in intensity as well the duration of the training (compare a short training that is high in intensity with a long training that is low in intensity).

 Prior to exercise, basic nutrition is sufficient to provide the energy you need during the bout of exercise. As an endurance athlete you have an increased carbohydrate requirement (see table 2) to replenish glycogen stores in the muscles and an increased protein requirement (see Table 3).

2 Whey protein is generally superior to other protein powders due to its favorable amino acid profile; whey protein contains a lot of leucine, which has an anabolic (muscle gain stimulating) effect in the body (Berrazaga, Micard, Gueugneau, & Walrand, 2019). 3 There are vegan variations of protein powders on the market with a modified amino acid profile, making them more equivalent to the animal variants. Check the label.

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Table 2: Carbohydrate requirements for endurance athletes (Thomas, Erdman, & Burke, 2016)

Table 3: Protein requirements for endurance athletes Source Endurance sports (protein as g/kg/day) Academy of Nutrition and Dietetics, Dietitians of Canada, and 1.2-2.0* the American College of Sports Medicine (2016) International Society of Sport-specific nutrition (2017) 1.4-2.0* * = +20% for vegetarians who scarcely eat animal products, +30% for vegans (Health Council of the Netherlands, 2001)

 Carbohydrates serve as the main form of fuel for endurance athletes (fast and efficient form of energy).4 Carbohydrate stores are depleted after an intensive ~45- to 60-minute workout (specifically in the used/exhausted muscles) (Burke, Wong, Hawley, & Jeukendrup, 2011). Table 4 shows what an optimal supplement of carbohydrates during exercise would look like.

 Fluids, carbohydrates and protein are recommended to promote recovery post-exercise. An easy mnemonic is: ◦ Rehydrate: water (fluids) (±150% per lost kg bodyweight during exercise) ◦ Replenish: carbohydrates ◦ Repair: protein

The combination of carbohydrates and proteins provide a better recovery than if only carbohydrates or proteins would be consumed (Cintineao, Arent, Antonio, & Arent, 2018) (Academy of Nutrition and Dietetics, Dietitians of Canada & The American College of Sports Medicine, 2016) (Wardenaar, et al., 2014). This can be achieved with for instance a meal or snack that contains (at least) 0.8 g/kg of carbohydrates together with 0.25-0.4 g/kg of protein. The exact amounts of carbohydrates and proteins will depend on the total carbohydrate and protein requirements of an athlete, on the intensity of a workout and on how the meals are distributed during the day. The effect of a carbohydrate-rich diet on the glycogen stores in the muscles and liver is shown in Figure 1.

A carbohydrate-rich diet optimally consists of products/foods that are recommended as basic nutrition, in particular complex carbohydrates. In some cases, supplementation with fast carbohydrates may be needed.

4 Low carbohydrate diets (50 to a maximum of 150 g carbohydrates per day) and ketogenic diets (20 to a maximum of 50 g carbohydrates per day) seem popular among endurance athletes. However, there is no scientific evidence to date that this has a greater performance- enhancing effect compared to carbohydrate-rich foods (Burke, et al., 2017).

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Depending on the intensity of the bout of exercise, this may be recommended for competitive or top-level athletes. If you decide to use sports drinks, sports bars and/or sports gels, carefully read the packaging of these products to determine which products (and quantities) are suitable for you in which situation.

Table 4: Carbohydrates during exercise (Academy of Nutrition and Dietetics, Dietitians of Canada & The American College of Sports Medicine, 2016) Activity Recommended Type of carbohydrate Glucose + fructose duration amount

< 45 min N/A N/A N/A N/A Suitable/ 45 – 75 min Mouth rinse Most types of carbohydrates Suitable recommended Suitable/ 1 – 2.5 hours 30-60 g per hour Most types of carbohydrates Suitable recommended Combinations of glucose:fructose or maltodextrin:fructose Suitable in (approximate ratio 2:1) are combination with Suitable/ > 2.5 – 3 hours Up to 90 g per hour sometimes better tolerated another form of recommended than a single type of carbohydrates carbohydrates

Figure 1: Restoration of carbohydrates (Senders, 2019) Prolonged effort Replenishment of glycogen stores

Carbohydrate rich diet

No food Fat + protein rich diet (Low carbohydrate diet) Glycogen content in muscle content muscle Glycogen in muscle (g/kg mass) Recovery time 5 Days Rest (hours)

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4. Protein for vegetarians and vegans Depending on which type of vegetarian you are, achieving your protein requirement doesn’t have to be a problem. It becomes more challenging if you only occasionally eat products of animal origin and have an imbalanced diet. The Dutch Health Council recommends lacto-ovo vegetarians to increase their protein intakes by 20%, in comparison to people with an omnivorous diet (Health Council of the Netherlands, 2001). The advice for vegans is to increase their protein intake by 30%, compared to omnivores. But everything stands or falls with the composition of your daily diet (Berrazaga, Micard, Gueugneau, & Walrand, 2019). Both vegans and vegetarians who barely consume animal products are advised to eat as varied as possible (Health Council of the Netherlands, 2001) (Van Vliet, Burd, & Van Loon, 2015). See the document “Basic nutrition” for more information on plant- based protein. Consult a (sports) dietician if you are unsure whether you are getting enough nutrient, or if you want to know whether your diet can support the sports performance(s) you strive for.

5. Timing and distribution of nutrients The timing of nutrients (in other words: the moments surrounding the training when you should consume carbohydrates and proteins) is not essential for everyone. As for protein, the distribution of the daily protein needs over several servings per day is the most important (International Society of Sports Nutrition, 2017), so that your body has a continuous supply of proteins5. The timing (mainly of carbohydrates for the resynthesis of muscle glycogen in endurance sports) only starts to play a role if: - the effort is intense and lasts longer than an hour (see Table 3), - you have to exert yourself again within 24 hours after the previous exercise bout (Burke, Van Loon, & Hawley, 2017), - you are not recovering sufficiently between training sessions (while other circumstances such as sleep, rest and stress reduction are optimal). The more advanced you are as an athlete, and/or the more intense and longer in duration your training sessions are, the more important the timing of nutrients becomes for an optimal recovery (Academy of Nutrition and Dietetics, Dietitians of Canada & The American College of Sports Medicine, 2016). Timing may also be of importance for athletes who have to make weight.

5 It is often thought that casein is the best protein source before sleep, but research reveals that this is not (always) the case. Animal based protein enhances protein synthesis more when compared to plant-based-proteins, but the type of animal protein does not seem to matter (Thomas, Erdman, & Burke, 2016).

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References Academy of Nutrition and Dietetics, Dietitians of Canada & The American College of Sports Medicine. (2016). Nutrition and Athletic Performance. Journal of the Academy of Nutrition and Dietetics, 48(3), 501-528. doi:10.1249/MSS.0000000000000852

Ayotte, D., & Corcoran, M. P. (2018). Individualized hydration plans improve performance outcomes for collegiate athletes engaging in in-season training. Journal of the International Society of Sport-specific nutrition. doi:10.1186/s12970-018-0230-2

Berrazaga, I., Micard, V., Gueugneau, M., & Walrand, S. (2019). The Role of the Anabolic Properties of Plant- versus Animal-Based Protein Sources in Supporting Muscle Mass Maintenance: A Critical Review. Nutrients, 11(8). doi:doi.org/10.3390/nu11081825

Burke, L. M., & Deakin, V. (2015). Clinical sport-specific nutrition (5 ed.). Mcgraw-Hill Education.

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

Burke, L. M., Wong, S. H., Hawley, J. A., & Jeukendrup, A. (2011). Carbohydrates for training and competition. Journal of Sports Sciences, S17-21. doi:10.1080/02640414.2011.585473

Cintineao, H. P., Arent, M. A., Antonio, J., & Arent, S. A. (2018). Effects of Protein Supplementation on Performance and Recovery in Resistance and Endurance Training. Frontiers in Nutrition. doi:https://doi.org/10.3389/fnut.2018.00083

Gorissen, S. H., Crombag, J. J., Senden, J. M., Waterval, H. W., Bierau, J., Verdijk, L. B., & Van Loon, L. J. (2018). Protein content and amino acid composition of commercially available plant-based protein isolates. Amino Acids, 1685–1695. doi:10.1007/s00726-018-2640-5

Goulet, E. D. (2013). Performance Effects of Dehydration. In R. J. Maughan, The Encyclopaedia of Sports Medicine: An IOC Medical Commission Publication (pp. 185-198). International Olympic Committee. doi:10.1002/9781118692318

Goulet, E. D., & Hoffman, M. D. (2019). Impact of Ad Libitum Versus Programmed Drinking on Endurance Performance: A Systematic Review with Meta-Analysis. Sports Medicine, 49(2), 221-232. doi:10.1007/s40279-018-01051-z

Health Council of the Netherlands. (2015). Background document: Guidelines for fibre consumption. The Hague: Health Council of the Netherlands.

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Hoffman, M. D., Cotter, J. D., Coulet, É. D., & Laursen, P. B. (2016). VIEW: Is Drinking to Thirst Adequate to Appropriately Maintain Hydration Status During Prolonged Endurance Exercise? Yes. Wilderness and Environmental Medicine, 27(2), 192-5. doi:10.1016/j.wem.2016.03.003

International Society of Sport-specific nutrition. (2017). International Society of Sport-specific nutrition Position Stand: protein and exercise. Journal of the International Society of Sport-specific nutrition. doi:10.1186/s12970-017-0177-8

Lewis-McCormick, I. (2012). A Woman's Guide to Muscle and Strength. Human Kinetics Publishers.

McArdle, W. D., Katch, F. I., & Katch, V. L. (2015). Exercise Physiology: Nutrition, energy, and human performance. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins.

Morton, R. W., Murphy, K. T., McKellar, S. R., Schoenfeld, B. J., Henselmans, M., Helms, E., . . . Phillips, S. M. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine, 52(6), 376-384. doi:10.1136/bjsports-2017-097608

Phillips, S. M., & Van Loon, L. J. (2011). Dietary protein for athletes: from requirements to optimum adaptation. Journal of Sports Sciences, 29, S29-38. doi:10.1080/02640414.2011.619204

Schoenfeld, B. J., & Aragon, A. A. (2018). How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution. Journal of the International Society of Sport-specific nutrition volume, 10. doi:doi.org/10.1186/s12970-018-0215-1

Senders, F. (2019). Sport en voeding. Retrieved from https://www.slideshare.net/: https://www.slideshare.net/FrankSenders/sport-en-voeding

Thomas, T. D., Erdman, K. A., & Burke, L. M. (2016). Nutrition and Athletic Performance. Medicine and science in sports and exercise, 48(3), 543-568. doi:10.1249/MSS.0000000000000852

Van Vliet, S., Burd, N. A., & Van Loon, L. J. (2015). The Skeletal Muscle Anabolic Response to Plant- versus Animal- Based Protein Consumption. The Journal of Nutrition, 145(9), 1981-91. doi:10.3945/jn.114.204305

Wardenaar, F., Maas, T., Pannekoek, S., Danen, S., Van Leijen, E., & Van Dijk, J.-W. (2014). Dieetbehandelingsrichtlijn 36: Wedstrijdsport. Rotterdam: Uitgevers 2010.

Wardernaar, F., Brinkmans, N., Ceelen, I., Van Rooij, B., Mensink, M., Witkamp, R., & De Vries, J. (2017). Micronutrient Intakes in 553 Dutch Elite and Sub-Elite Athletes: Prevalence of Low and High Intakes in Users and Non-Users of Nutritional Supplements. Nutrients.

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