Sports nutrition: case studies 2.

Continuing education and the APD program

This quiz is an ideal activity for APD members to include in your CPD log, where it relates to personal learning goals. Record the time taken, to the nearest hour, to complete the quiz and any associated research.

INTRODUCTION

The case study in the previous issue (1) identified several aspects of sports nutrition relevant to endurance athletes, particularly females. This case study and the last should show readers how different athletes can be in their sports nutrition needs. This issue we highlight different aspects of nutritional need for a young male athlete with limited food preparation, skills and training for an intermittent sport. Supplementation is also a subject that creates confusion among athletes and receives some attention in this case. The case study presented is fictitious and draws on the experience of practising sports dietitians.

Questions 1-4 relate to the following case study:

The athlete: Trent

Trent is a 19-year-old male basketball player who has recently signed a contract with the a major national league team. Trent has spent the previous two years at the national sports institute living in residence (all meals provided). He is currently living in shared accommodation in Sydney with two other players as his parents live in Brisbane. His only experience in the kitchen was the two cooking classes he did while at the institute, which he did not get very involved in because he had planned to move back to Brisbane to live with Mum and Dad.

His current weight is 89 kg and height is 202 cm and sum of seven skinfolds 60 mm. Trent usually trains twice daily and includes strength training three times per week.

Reason for consultancy

He has made an appointment to see you privately because his coach has encouraged him to increase his body weight in order to challenge for a starting-five position. He wants to increase his lean body mass, so he has more muscle to throw around the court. He managed to gain some weight while at the institute; however, he needs to gain at least 5 kg in order to challenge for a key position within the team.

Current dietary patterns

A couple of the senior players in the team have convinced him to start taking whey protein (analysis: 22 g of protein, 2 g of carbohydrate per serve) and have encouraged him to start using creatine monohydrate (he has not started yet, but was after your advice). His current intake includes three meals each day with inconsistent snacks. Most meals at lunch and dinner are purchased and consumed on the run. He loves his X-Box in the afternoon, so usually has a snack while playing this for a couple of hours. A sample daily intake is outlined in Table 1.

Professional assessment

Given the subjective dietary history, it is difficult to accurately access total daily energy and nutrient intake. Trent realises the significance of gaining weight and is motivated to make dietary modifications. He is annoyed; he did not listen more to the Sports Dietitian at the national sporting institute and is keen to improve on his limited cooking skills.

1. Which of the following nutrition strategies would be prioritised to assist Trent in achieving his goal of increased muscle mass?

a. Increase total energy intake with particular emphasis on recovery of carbohydrate between sessions

b. Increase overall protein intake

c. Use creatine supplementation to improve muscle tissue growth

d. Improve the timing and nutritional composition of his meals to maximise recovery between training sessions

e. a and d

2. Which is the least true in relation to Trent's protein requirements?

a. Trent should be aiming to get in large amounts of protein as his requirements are much higher than a normal athlete

b. Trent should aim for about 1.4-1.7 g of protein per kilogram body weight per day

c. Trent should concentrate on nutrient dense carbohydrate

d. Trent will eat more than enough protein in a high energy eating plan that meets his carbohydrate requirements

3. Which of the below statements best describes Trent's suitability for powdered supplements?

a. Trent should be eating whole foods. Nutritional supplements are only suitable for nutritionally compromised patients

b. He should try a nutritionally balanced sports meal replacement which meets his recovery requirements

c. The protein powder Trent is currently taking is perfectly fine and should be used more regularly

d. Nutritional supplements are suitable in situations of convenience

e. b and d

4. Which of the following statements is the most accurate advice about creatine monohydrate in the above situation?

a. Trent should trial supplementing his diet with 3 g of creatine

b. Trent should take creatine as it increases weight immediately

c. Creatine is not suitable for any athlete and is banned under World Anti-Doping Authority (WADA)

d. Creatine is only suitable for body builders and can lead to muscle cramps and tears

e. Trent should work on his basic recovery nutrition first and potentially consider creatine supplementation in the future

ANSWERS

1. e.

An athlete's inability to increase lean muscle tissue is often a result of poor nutritional recovery habits between training sessions rather than insufficient intake of protein over the day. An unplanned, disorganised intake of food and fluid throughout the day makes it difficult for an athlete to recover muscle and liver glycogen stores between training sessions and also makes it difficult to create the energy surplus required for lean muscle mass gain. Keeping pace with daily fuel requirements to sustain quality exercise, while creating an energy surplus to allow for muscle mass gain is a major challenge for most athletes.

Careful planning is required to ensure adequate carbohydrate replenishment between sessions, especially if they are less than eight hours apart, (2) and creating positive energy balance which is essential for increasing muscle mass. (3,4) The amount of dietary protein is not usually a limiting factor that restricts individual's ability to increase lean muscle tissue. In fact, most athletes habitually consume more than their protein requirements. (5) Creatine supplementation may be considered in Trent's case, but would not be a prioritised strategy (see question 4). Ensuring Trent has access to snacks containing protein (6-12 g of essential amino acids or 10-20 g of high-biological-value protein (HBV)) and carbohydrate (1 g per kilogram body mass) one hour before resistance training sessions may improve muscle tissue development. (5-8) This snack should be repeated within 30 minutes after training to begin glycogen replenishment and optimise opportunity for protein synthesis. (8) Because of the duration and frequency of Trent's training, he needs to eat carbohydrate-rich meals, containing adequate protein between training sessions in order to sufficiently recover glycogen stores for the next bout of activity. This may be consumed in any combination of meals (e.g. one large and three small or three large or six small) that is practical and suitable for Trent with particular consideration to requirements being met. (2) Nutrition strategies to optimise Trent's ability to increase lean muscle tissue would be prioritised first by meeting his energy/carbohydrate requirements through a balance of nutrient-dense carbohydrate-protein foods throughout the day, and second by planning pre-training and recovery meals/snacks to ensure adequate timing and availability of carbohydrate and protein especially before resistance training sessions.

2. a.

It is common perception among athletes that to increase lean muscle tissue they need to increase protein intake dramatically Nitrogen balance studies performed on novice and experienced strength trained athletes indicate that Trent's protein requirement would be in the realm of 1.5-1.7 g/kg/day to meet daily requirements and facilitate muscle accretion. (9,10) As discussed in the answer to question 1, absolute protein intake is usually not the limiting factor in lean muscle tissue development so focusing on other areas of nutrition may be more beneficial. Tipton and colleagues have shown that other factors such as nutrient composition and timing of protein foods may affect protein utilisation by muscle tissue and hence the ability to develop lean muscle tissue. (6,11,12) The type of protein, (6,13) amino acid composition (14) as well as carbohydrate content (7) also affect muscle protein uptake and utilisation. All these factors need to be taken into account when recommending food and fluid intake around training sessions and throughout the day.

Examples of recovery snacks that provide 50 g of carbohydrate and at least 10 g of protein are provided in Table 2.

3. e.

The availability of sufficient recovery foods seems to be a major problem for Trent and making nutritional recovery as easy as possible is a common theme when dealing with athletes. Athletes often have difficulty consuming the volume of whole foods required to put on lean muscle tissue especially when they also have high training demands. Because of the large energy requirements, nutritional supplementation is often an effective way of making it easier for athletes to consume the energy and nutrients required. Specifically designed sports nutrition supplements play an important role in nutritional recovery especially in athletes who have very high energy requirements, are in heavy training or competition and striving to gain weight. (15,16) As discussed in answering question 1, Trent's recovery needs should be met by a nutrient dense carbohydrate food source that contains ~6-12 g of essential amino acids (10-20 g of HBV protein) and 1 g of carbohydrate per kilogram body weight. (2,8) The current protein powder that Trent is taking may contain sufficient protein but does not contain sufficient carbohydrate to improve utilisation by the muscle tissue. (7) A sports meal replacement beverage would be a suitable supplement as well as being portable and convenient. Athletes and dietitians should be aware of the hidden pitfalls of supplements. While most sports foods and supplements are safe, some athletes in the international sporting community have tested positive to performance enhancing substances via their intake of sports foods or supplements because of contamination or inclusion of unlisted ingredients in the product, or plain ignorance of banned ingredients. (15,16) Elite athletes and their dietitians should consult the Australian Sports Anti-Drug Authority and the relevant sports institute rulings on supplement usage. Many sports foods and nutritional supplements are considered safe for use and can provide some benefit to the athlete in specific circumstances. Nutritional supplementation should be used in conjunction with whole foods to make it easier for an athlete to meet their requirements throughout the day.

4. e.

Creatine is a chemical that is used to regenerate ATP stores and is primarily stored in skeletal muscle tissue of which 60-65% is phosphorylated. (15) This creatine phosphate (CrP) is used to rapidly replenish ATP stores during maximal efforts and is essential in efforts lasting 5-10 seconds. (15) The daily turnover of creatine is ~1-2 g and can be replaced through dietary consumption of animal muscle products such as meat and eggs, and is also produced endogenously from arginine, glycine and methionine. (15) A study by Harris et al. demonstrated that muscle creatine stores could be increased by oral loading. (17) The protocol for loading creatine in this study was four to six doses of 5 g of creatine monohydrate per day for five days to saturate muscle creatine stores and increase concentrations by 20%. Saturation occurred in about two to three days and the best results were seen in athletes with the lowest pre-supplementation concentrations and when coupled with intensive daily exercise. (17) Creatine supplementation of 3 g/day over a period of 28 days has also been shown to achieve similar results through slow loading and can be sustained by a dose of 2-3 g/day. (18) About 30% of individuals fail to see significant increases in muscle creatine stores and would be classified as 'non-responders'. (19,20) The increase in creatine stores improves the ability of an individual to regenerate ATP stores during the recovery period of repeated short high-intensity exercise bouts. Most of the ergogenic effects of creatine are seen in sports where athletes are involved in repeat high-intensity efforts (i.e. basketball). A body mass gain of ~1 kg has been reported during creatine loading because of gains in body water. Anecdotal reports of nausea, gastrointestinal upsets and muscle cramps/strains are often experienced. (15) The final two symptoms may be attributed to the increased water storage in skeletal muscle seen in acute loading. But studies by Greenwood et al. and Kreider et al. have shown no increased prevalence of risk in creatine users. (21-23)

Creatine is not banned under the WADA antidoping code, but reliable sources should be used because of the high prevalence of sports supplements containing banned substances. (24) Recommendations are that creatine should be used by well-developed adult athletes and substantial performance gains would be expected through training and correct nutritional recovery before creatine supplementation would be considered.

Readers are referred to Greenhaff, (20) Burke et al. (15) and reviews by Spriet19 and Hespel et al. (25)

REFERENCES

1 Cox G, Shaw G, Barnard J. Continuing education. Sports nutrition: case studies. Nutr Diet 2007; 64: 62-6.

2 Burke L, Kiens B, Ivy J. Carbohydrates and fat for training and recovery. J Sports Sci 2004; 22: 15-30.

3 Todd KS, Butterfield GE, Calloway DH. Nitrogen balance in men with adequate and deficient energy intake at three levels of work. J Nutr 1984; 114: 2107-18.

4 Tipton K, Wolfe R. Protein and amino acids for athletes. In: Coyle E, ed. Food, Nutrition and Sports Performance 2. The IOC Consensus on Sports Nutrition. London: Routledge, 2004; 104-29.

5 Tarnopolsky M. Protein and amino acid needs for training and bulking up. In: Burke L, Deakin V, eds. Clinical Sports Nutrition, 3rd edn. Sydney: McGraw-Hill Company Australia Pty Limited, 2006; 73-111.

6 Tipton KD, Rasmussen BB, Miller SL et al. Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise. Am J Physiol Endocrinol Metab 2001; 281: E197-206.

7 Rasmussen B, Tipton KD, Miller SL et al. An oral essential amino acid-carbohydrate supplement enhances muscle protein anabolism after resistance exercise. J Appl Physiol 2000; 88: 386-92.

8 Burke L, Tipton K. Nutrition for Optimal Recovery. State-of-the-Art Report Prepared for the Department of Sports Nutrition, Australian Institute of Sport. Canberra: Australian Sports Commission, 2003.

9 Lemon PW, Tarnopolsky MA, MacDougall JD et al. Protein requirements and muscle mass/strength changes during intensive training in novice bodybuilders. J Appl Physiol 1992; 73: 767-75.

10 Tarnopolsky MA, Atkinson SA, MacDougall JD et al. Evaluation of protein requirements for trained strength athletes. J Appl Physiol 1992; 73: 1986-95.

11 Tipton KD, Borsheim E, Wolf SE et al. Acute response of net muscle protein balance reflects 24-h balance after exercise and amino acid ingestion. Am J Physiol Endocrinol Metab 2003; 284: E76-89.

12 Borsheim E, Tipton KD, Wolf SE et al. Essential amino acids and muscle protein recovery from resistance exercise. Am J Physiol Endocrinol Metab 2002; 283: E648-57.

13 Phillips SM, Hartman JW, Wilkinson SB. Dietary protein to support anabolism with resistance exercise in young men. J Am Coll Nutr 2005; 24: 134S-9S.

14 Tipton KD, Ferrando AA, Phillips SM et al. Postexercise net protein synthesis in human muscle from orally administered amino acids. Am J Physiol 1999; 276: E628-34.

15 Burke L, Cort M, Cox G et al. Supplements and sports foods. In: Burkc L, Deakin V, eds. Clinical Sports Nutrition, 3rd edn. Sydney: McGraw-Hill Company Australia Pty Limited, 2006; 485-579.

16 Maughan R, King D, Lea T. Dietary supplements. In: Maughan R, Burke L, Coyle E, eds. Food, Nutrition and Sports Performance 2. The IOC Consensus on Sports Nutrition. London: Routledge, 2004; 153-85.

17 Harris RC, Soderlund K, Hultman E. Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation. Clin Sci (Lond) 1992; 83: 367-74.

18 Hultman E, Soderlund K, Timmons JA et al. Muscle creatine loading in men. J Appl Physiol 1996; 81: 232-7.

19 Spriet L. Ergogenic aids: recent advances and retreats. In: Murray D, ed. Optimizing Sports Performance. Carmel: Cooper Publishing, 1997; 185-238.

20 Greenhaff P. Creatine. In: Maughan R, ed. Nutrition in Sport. Oxford: Blackwell, 2000; 379-92.

21 Greenwood M, Kreider RB, Melton C et al. Creatine supplementation during college football training does not increase the incidence of cramping or injury. Mol Cell Biochem 2003; 244: 83-8.

22 Greenwood M, Kreider RB, Greenwood L et al. Cramping and injury incidence in collegiate football players are reduced by creatine supplementation. J Athl Train 2003; 38: 216-19.

23 Kreider RB, Melton C, Rasmussen CJ et al. Long-term creatine supplementation does not significantly affect clinical markers of health in athletes. Mol Cell Biochem 2003; 244: 95-104.

24 Geyer H, Parr MK, Mareck U et al. Analysis of non-hormonal nutritional supplements for anabolic-androgenic steroids-results of an international study. Int J Sports Med 2004; 25: 124-9.

25 Hespel P, Eijnde BO, Derave W et al. Creatine supplementation: exploring the role of the creatine kinase/phosphocreatine system in human muscle. Can J Appl Physiol 2001; 26 (Suppl.): S79-102.

This quiz has been prepared by Greg Shaw, Greg Cox and Janelle Barnard on behalf of Sports Dietitians Australia. Correct answers follow the questions to allow readers to carry out self-assessment. Correspondence should be directed to Janelle Barnard, email: [e-mail]

Table 1 Sample daily intake for Trent

Breakfast                Lunch

8 breakfast biscuits     Usually takeout between
400 mL of full cream       training/physio/study
  milk + 1 tbsp sugar    For instance:
500 mL of orange juice   Hamburger x 2, large
400 mL of milk + 2 tbsp    fries/cola and
  formulated chocolate/    chocolate sundae
  malt beverage

Dinner                  Snacks

Counter meal at the     4-6 slices of toast mid afternoon
  local club:             with his whey protein drink
Spaghetti bolognaise      which is made with 400 mL
Roast chicken and oven    of full cream milk
  fries with tomato
  sauce

Table 2 Recovery snacks providing 50 g of carbohydrate and at least 10 g
of protein (a)

250 mL of sport-specific liquid meal supplement made on skim milk
4 breakfast biscuits with 1 cup of skim milk and tinned fruit
300 mL of low-fat flavoured milk and 1 large peanut butter sandwich
1 round of chicken and salad sandwich with 600 mL of sports drink
2 poached eggs on wholemeal toast with 250 mL of juice
2 slices of fruit toast and jam with a 200-g tub of plain yoghurt
1.5 cups of cooked pasta with 150 g of minced meat bolognaise sauce

(a) From Foodworks (V5.00) nutrient analysis software package (Xyris
software, Brisbane, Australia), containing the Australian nutrient
databases, NUTTAB95, AusFoods, AusNut, Abbott products, Novartis,
Nutricia 2003 (Revisions 24, 11, 18, 2, 1 and 6, respectively).