2019 PINES 10 Questions 10 Experts Session Highlights

2019 PINES 10 Questions 10 Experts Session Highlights

Sports Nutrition Myths: Busted!

Presented at the American College of Sports Medicine Annual Meeting, May 28, Orlando Florida

For professionals interested in nutrition for exercise and sport, the fast-moving PINES 10 Questions 10 Experts session is a highlight of the American College of Sports Medicine’s Annual Meeting. The theme of this year’s PINES 10 Questions 10 Experts session was Sports Nutrition Myths: Busted! Each speaker quickly addressed a specific sports nutrition myth in three minutes, followed by five minutes of discussion. Below four of the ten questions and answers have been summaries for those who were unable to attend.

MYTH: Eating just before bed makes an athlete fat.

Michael J. Ormsbee, PhD, FACSM,CSCS*D

If you eat too much of just about anything, at any time, chances are you’ll gain fat. In fact, older data indicate that a large mixed-meal (544 kcals: 15% protein, 35% fat, & 50% carbohydrate) eaten later at night does not stoke your metabolism the same what that the identical meal would earlier in the day. Theoretically, this could lead to overeating and thus, gaining body weight (and likely fat). However, for athletes, we need to think about nutrition over the entirety of the day, not just in certain windows. For some athletes, eating before sleep is not just recommended, but required! For example, in ultra-distance sports, not eating before sleep would easily lead to severe energy restriction and low nutrient availability for exercise. In addition, in physique sports like bodybuilding, there are countless anecdotal reports of not-only eating before sleep but also waking up to eat during the night. And these athletes are far from overweight or overfat.

Recently, data has mounted to show that consuming 30-40grams of a protein dominant meal prior to bed is no different in terms of overnight fat oxidation compared to a non-caloric placebo. Likewise, using the microdialysis technique in adipose tissue, pre-sleep casein protein does not change overnight lipolysis. Lastly, data over 12 weeks show that a nightly pre-sleep protein-centric beverage improves muscle mass and strength while simultaneously reducing total percent body fat.

In summary, it is plausible that eating just before bed can make an athlete fat if large amounts of mixed-meals are consumed. However, this myth is busted if the athlete choose protein dominant foods that are roughly 150-200kcals.

References

1. Romon et al. AM J Clin Nutr., 1993.
2. Madzima et al. BJN, 2014
3. Ormsbee et al, APNM, 2015
4. Snijders et al., J Nutr, 2015
5. Kinsey et al; Nutrients, 2016
6. Allman et al, in review

Author bio

Michael J. Ormsbee is an Associate Professor in the Department of Nutrition, Food and Exercise Sciences and the Associate Director of the Institute of Sports Sciences and Medicine at Florida State University. He serves as an Honorary Research Fellow at the University of KwaZulu-Natal in Durban, South Africa and is a Fellow of the American College of Sports Medicine. His research expertise involves the interaction of exercise training, nutrition and supplementation to improve metabolism and achieve optimal body composition, human performance, and health with special emphasis on pre-sleep feeding. Dr. Ormsbee was awarded the Florida State University Teacher of the Year award (2014), Graduate Faculty Mentor Award (2018), and was named the Nutrition Researcher of the Year (2017) by the National Strength and Conditioning Association.

Twitter: @mikeormsbee and @FSUISSM

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MYTH: The vegan diet is unlikely to support optimal performance in athletes due to lack of leucine to trigger muscle protein synthesis.

Nancy Clark. MS RD CSSD, Sports Nutrition Services LLC, Boston MA

Without a doubt, vegan athletes can be healthy (1). No evidence suggests a nutritionally adequate vegan diet impairs athletic performance. Google “vegan athletes,” and you’ll find an impressive list that includes Olympians and professional athletes from many sports (football, basketball, tennis, rowing, snow boarding, etc.)

The key to having an effective vegan sports diet is to consume adequate leucine, the essential amino acid that triggers muscles to grow (2). The richest sources of leucine are found in animal foods, such as eggs, dairy, fish, and meats. If a carnivore swaps animal proteins for plant proteins, the swap can reduce leucine intake by about 50%. Hence, vegan athletes need to pay attention to both the quantity and quality of the protein they choose to consume (3).

Vegan athletes should try to consume 2.5 grams of leucine every 3 to 4 hours during the day, to optimize muscular development. That means, they need to eat abundant nuts, tofu, beans, lentils, and other plant proteins regularly at every meal and snack. While most athletes can consume adequate leucine, many don’t because they skip meals and fail to plan a balanced vegan menu. If an athlete is restricting calories to lose body fat, the reduced calorie intake can lead to reduced leucine intake. Hence, weight-conscious vegan dieters need to be extra vigilant to consume an effective sports diet.

References

1. Wirnitzer, K., P. Boldt, C. Lechleitner, et al. 2018. Health Status of Female and Male Vegetarian and Vegan Endurance Runners Compared to Omnivores—Results from the NURMI Study (Step 2). Nutrients 11(1):29  doi: 10.3390/nu11010029 (Free access)
2. Churchward-Venne, T, N. Burd and S. Phillips. 2012. Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to .enhance anabolism. Nutr Metab 9:40  doi: 10.1186/1743-7075-9-40 (Free access)
3. Rogerson, D. 2017. Vegan diets: practical advice for athletes and exercisers. J Int Soc Sports Nutr 14;36  doi: 10.1186/s12970-017-0192-9 (Free access)

Author Bio

Nancy Clark MS RD CSSD has a private sports nutrition practice in the Boston area and is author of Nancy Clark’s Sports Nutrition Guidebook, 6th Edition (July 2019). www.NancyClarkRD.com

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MYTH: Females and males respond differently to popular sports supplements.

Louise M Burke, Chair of Nutrition Strategy, Australian Institute of Sport, Canberra and Chair of Sports Nutrition, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia

Females are under-represented in sports science research, with few studies involving solely female participants and even fewer being organized to investigate differences in the response between male and female athletes (1). The theme of greatest inequality involves interventions for performance enhancement. Yet, it is important to undertake studies with female athletes if sports nutrition guidelines are to be realistically applied to this population. There are several reasons to consider that females may have special or different responses to a nutrition intervention or supplement; these include differences in body size, the effects of specific sex hormones in the particular phase of the menstrual cycle, differences in nutritional status (e.g. energy availability or iron status) or other factors yet to be identified. In some cases, previous differences in responses of males and females to sports nutrition strategies have found to be a result of low energy availability than a true sex difference (2).

Newer research on the effectiveness of sports supplements has considered the possibility of sex differences. Lane and colleagues reported that caffeine (3 mg/kg BM in the form of caffeinated gum) was equally able to enhance performance (3-4%) of a road cycling time trial simulating the 2012 Olympic event in sub-elite male and female cyclists. It was noted, however, that different trial time courses were involved (~29 km for females and ~44 km for males). More recently, caffeine ingestion (3 mg/kg pre-exercise) was shown to improve the performance of a standardized cycling time trial a similar magnitude (~4%) in males and female athletes, despite significantly greater plasma caffeine concentrations after exercise in women (4). Thus, it seems that any sex differences related to caffeine and performance are minor. On the other hand, a study of sedentary individuals reported that females exhibited higher nitrite levels in saliva and urine despite similar nitrate levels to males; furthermore, they responded to nitrate supplementation with a greater increase in plasma nitrite than males (5). These findings, which were not associated with difference in the oral microbiome, support the need for studies of supplementation in athletes to investigate whether these results translate into differential performance benefits. Clearly, more attention to potential sex differences is warranted.

References

1. Costello JT, Bieuzen F, Bleakley CM. Where are all the female participants in Sports and Exercise Medicine research? Eur J Sport Sci.2014;14(8):847-51. doi: 10.1080/17461391.2014.911354.
2. Tarnopolsky MA, Zawada C, Richmond LB, Carter S, Shearer J, Graham T, Phillips SM. Gender differences in carbohydrate loading are related to energy intake. J Appl Physiol. 2001;91(1):225-30
3. Lane SC, Hawley JA, Desbrow B, Jones AM, Blackwell JR, Ross ML, Zemski AJ, Burke LM. Single and combined effects of beetroot juice and caffeine supplementation on cycling time trial performance. Appl Physiol Nutr Metab. 2014;39(9):1050-7
4. Skinner TL, Desbrow B, Arapova J, Schaumberg MA, Osborne J, Grant GD, Anoopkumar-Dukie S, Leveritt MD. Women Experience thi Same Ergogenic Response to Caffeine as Men. Med Sci Sports Exerc. 2019 Jun;51(6):1195-1202.
5. Free Radic Biol Med.2018 Oct;126:113-121. doi: 10.1016/j.freeradbiomed.2018.07.010. Epub 2018 Jul 20.
6. Sex differences in the nitrate-nitrite-NO^• pathway: Role of oral nitrate-reducing bacteria.
7. Kapil V¹, Rathod KS¹, Khambata RS¹, Bahra M¹, Velmurugan S¹, Purba A¹, S Watson D¹, Barnes MR¹, Wade WG², Ahluwalia A³.

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MYTH: Exogenous ketone supplements provide the health and performance effects of fasting and ketogenic diets.

Brendan Egan PhD CSCS, Dublin City University

Ketone bodies, namely β-hydroxybutyrate (βHB), acetoacetate and acetone, are produced by ketogenesis in the liver, with their production accelerated during states of low carbohydrate availability. βHB is the predominant ketone body in the circulation in physiological states. A βHB concentration above 0.5 mM is termed nutritional ketosis when achieved by approaches such as fasting and ketogenic diets.

Exogenous ketone supplements comprise of novel dietary supplements that aim to acutely elevate βHB concentrations to produce acute nutritional ketosis. These supplements are typically available in the form of ketone esters, ketone salts and ketogenic agents such as medium change triglycerides, each of which produce a range of elevations in blood βHB concentrations. The most potent of these supplements to elevate βHB concentrations is a ketone ester known as the βHB ketone monoester, which was initially developed with the aim of improving the physical and cognitive performance of warfighters.

Recent explorations have been around the value of the array of exogenous ketone supplements in athletic performance, recovery from exercise, glycemic regulation, antiseizure effects, neuroprotection and cognitive function, and anticatabolic actions. In the performance and recovery paradigm, results have been equivocal, but there appears to several promising reports to date in a range of therapeutic applications.

Nutritional ketosis defined by the elevation in βHB concentrations is therefore common to fasting, ketogenic diets and the ingestion of exogenous ketone supplements. However, the methods to achieve ketosis are fundamentally different. Fasting and ketogenic diets require >12 hours up to several days produce ketosis and can be considered to be by endogenous means, whereas ketone supplements produce ketosis acutely several minutes after ingestion (and therefore, exogenous means) with effects lasting for ~1 to 3 hours. While similarities exist between endogenous versus exogenous ketosis e.g. suppression of appetite, decreased reliance on carbohydrate during exercise, there are marked differences too. Most notably, any performance benefits of exogenous ketone supplements are likely to occur with carbohydrate co-ingestion as opposed to be restriction of carbohydrate in dietary approaches to ketosis. Moreover, in contrast to the marked elevation of free fatty acids that is essential to produce a ketogenic state, exogenous ketone supplements are anti-lipolytic, and acutely lower circulating free fatty acids.

In summary, whether one considers exogenous ketone supplements to be analogous to the fasting and ketogenic diets will be largely dependent on the physiological/metabolic parameters and contexts under discussion. In any case, the health and performance effects of any ketosis-inducing approach are in need of much further investigation.

References

1. Koutnik AP, D’Agostino DP, Egan B. Anticatabolic Effects of Ketone Bodies in Skeletal Muscle. Trends Endocrinol Metab. 2019 30(4):227-229. doi:10.1016/j.tem.2019.01.006.
2. Evans M, Egan B. Intermittent Running and Cognitive Performance after Ketone Ester Ingestion. Med Sci Sports Exerc. 2018 50(11):2330-2338. doi:10.1249/MSS.0000000000001700.
3. Egan B. The glucose-lowering effects of exogenous ketones: is there therapeutic potential? J Physiol. 2018 596(8):1317-1318. doi: 10.1113/JP275938.
4. Evans M, Cogan KE, Egan B. Metabolism of ketone bodies during exercise and training: physiological basis for exogenous supplementation. J Physiol. 2017 595(9):2857-2871. doi:10.1113/JP273185.
5. Veech RL, Chance B, Kashiwaya Y, Lardy HA, Cahill GF Jr. Ketone bodies, potential therapeutic uses. IUBMB Life. 2001 51(4):241-7.

Author bio

Brendan Egan, PhD is an Associate Professor of Sport and Exercise Physiology at Dublin City University, Ireland. His research investigates the molecular regulation of skeletal muscle function and adaptation across the life course, with special interest in the synergy between nutrition and exercise interventions to optimise performance in athletes and elderly. He works as a performance nutritionist with the Dublin Hurling and Irish Paratriathlete teams.

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This year’s PINES session was supported by Unit Nutrition.