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SPORTS COACH An online magazine for coaches ISSN 1836-604X VOLUME 29 NUMBER 2 2006 Event-specific nutrition and relationship to weight control Author: Michelle Cort, Sports Dietitian, Department of Sports Nutrition, Australian Institute Of Sport Issue: Volume 29 Number 2 Various aspects of exercise performance are favoured by certain physical characteristics. Elite athletes therefore tend towards a physique that supports the demands of a specific event. Refining an athletes basic physique (level of body fat and/or muscle mass) through diet and training is necessary in order to achieve optimal performance. Both coaches and athletes are inundated with an enormous amount of misinformation regarding methods of achieving weight control. This article aims to dispel some of this misinformation and to provide advice on eventspecific weight-control strategies and challenges. Weight control Dietary approaches to facilitate weight control range from modest reduction in dietary fat and energy intake to severe restrictions in total energy intake and carbohydrate. For a number of athletes, interventions that focus on the reduction of fat intake are sufficient to produce the desired weight control. The advantage of this strategy for many athletes is that glycogen depletion is unlikely. Other athletes will also have to restrict total energy, fat and carbohydrate intake. In these cases maintaining satiety through adequate protein intake and the use of low-glycaemic index (GI) carbohydrates can be useful. Event-specific issues as well as considerations as to whether the athlete is in a heavy training phase, competition phase or a lower energy expenditure phase (due to injury, illness or the off-season) need to be evaluated when developing a weight control plan. Event-specific issues and weight control Strength sports The weight goal of most athletes in strength based sports is optimising their power to weight ratio. This often involves aiming to reduce body fat (see Table 1) whilst maintaining (or increasing) lean muscle mass. © Australian Sports Commission Page 1 of 4 Although in some lifting and throwing events a high body fat level is not a big disadvantage, there are events where an athlete could benefit by reducing body fat levels. For example low and middle weight weightlifting and power lifting divisions (See 'Making Weight'). Speed/sprint sports Low body fat levels tend to occur naturally for many athletes competing in these events (eg: jumps, sprints, hurdles). However some athletes may need to manipulate food intake to achieve their desired body fat levels. Competition will not deplete glycogen stores for these athletes and carbohydrate loading offers no benefit. The gain in body weight due to additional glycogen and water is just extra weight to carry and therefore could be a disadvantage to performance. Endurance sports Low body fat levels are an advantage to endurance athletes (eg: runners, road cyclists and triathletes) as they transport their body over many kilometres. Usually genetics and training load will ensure low body fat levels. If not, the strategies in Table 1 are a good starting point. Aesthetic sports Athletes involved in these ‘appearance sports’ (eg: gymnastics, figure skating, diving and ballet) often want to achieve lower body fat than is natural for their bodies. The athletes training diet may be energy restricted therefore careful meal planning is necessary to ensure that it is nutrient dense and contains adequate carbohydrate for training and health. There is a risk of weight gain during competition if the athletes energy intake is not kept relative to the reduced energy expenditure of a very reduced training load. Skill-based sports Athletes involved in sports such as archery and golf don’t burn many kilojoules during training or competition. Weight control may be desired to improve health and fitness which may consequently effect performance. See Table 1. Exercise phase and weight control Heavy training phase Undertaking an increased exercise load may lead to the athlete compensating for an increased energy expenditure by consuming more food. If this food results in excess consumption of kilojoules, an unwanted increase in body weight could result. Care should be taken to ensure that while energy requirements for training are met the athlete is consuming foods throughout their meal plan to maximise satiety (eg: protein choices at each meal and low GI foods) so that the risk of over-consumption is minimised. Reduced exercise/energy expenditure Page 2 of 4 Athletes may be susceptible to body fat increases during periods of reduced exercise (eg: off-season, injury or illness). Appropriate guidance with the athletes nutrition plan during these times is necessary. Immediate post-exercise energy intake An athletes nutrition recovery requirements will vary depending on intensity and length of exercise sessions as well as body composition goals. Professional advice should be sought regarding specific amounts and types of recovery foods and fluids necessary. A useful strategy for those athletes aiming to decrease body weight can be to plan for meals to follow training sessions so that recovery is achieved using nutritious food options within the athletes daily kilojoule budget. Post-competition excess The post competition phase is often seen as a time for athletes to let their hair down and relax strict eating plans. Bingeing on food and alcohol can lead to problems with weight goals if undertaken regularly. Travel Athletes constantly on the circuit (eg: tennis, cricket) will need to be aware of how to maintain their nutrition plan while travelling. Research prior to leaving home regarding the availability of foods at the destination and packing of appropriate food supplies may be necessary to avoid weight gain. As can be recognised from the information presented above methods of successful weight control will differ from individual to individual, however several general strategies can be applied to most athletes: Making weight If making weight is required close to competition, 24 hrs of moderate dehydration (less than 3 per cent body weight), mild food restriction and a low residue diet on the day immediately before competition may be less harmful to athletes than more extreme measures. Appropriate re-fuelling and re-hydration strategies between weigh in and competition should then be employed. Increasing weight (muscle mass) Many theories exist as to the best way to achieve muscle mass gain. The major requirements for weight gain however include: genetic potential, a well designed weight training program, high energy diet, and appropriate timing and type of protein ingestion. The following list highlights the major dietary considerations. • An increase in total energy intake is essential. • Consuming adequate energy can be difficult when undertaking frequent and prolonged training sessions (eg time constraints, lack of appetite). Inclusion of energy dense foods and fluids (eg: trail mix, Protein Plus drink, smoothies) can help meet energy intake goals. • Consuming a protein-carbohydrate containing snack prior to and after resistance training sessions can help to maximise training adaptations and muscle mass growth (eg: tub yoghurt, 300ml milk, 250ml Protein Plus Drink). • Essential amino acids are necessary for stimulation of muscle mass growth. Therefore spreading good quality protein throughout the day is advised. Athletes should aim to follow these strategies throughout the week and not just on training days. Page 3 of 4 Further information and advice More detailed information can be obtained from both the Australian Institute of Sport, Department of Sports Nutrition website www.ausport.gov.au/ais/nutrition < http://www.ausport.gov.au/ais/nutrition > Individualised, professional advice can be sought from a member of Sports Dietitians Australia. To find a Sports Dietitian in your local area go to www.sportsdietitians.com.au. < http://www.sportsdietitians.com.au > Weight-control strategies Methods of successful weight control will differ from individual to individual, however several general strategies can be applied to most athletes: • Begin with a low fat diet with moderate energy restriction, (aim: 0.5-1kg per week). • For events where more rigorous dietary restriction, (due to extreme leanness being required, or when the athlete is aiming to make weight), professional advice from a sports dietitian is warranted. • Protein choices at each meal along with low GI carbohydrate choices may help with satiety. • Regular consumption of nutrient-rich, lower-energy dense meals and snacks is recommended to prevent excessive hunger. • Organisation and planning to avoid 'impulse eating' should be encouraged. • Planning meals to follow training sessions will promote recovery using nutritious food options within the athletes daily kilojoule budget. • Energy dense sports food products/fluids should be minimised and only be consumed during main training sessions (especially longer, strenuous sessions) or during competition. • Calcium in dairy products seems to play a role in weight control. Inclusion of low fat dairy sources in the meal plan is encouraged. • Shopping and cooking skills may need to be improved in order to achieve weight control goals. • Psychological aspects and behaviour modification may have to be investigated and professional advice from a sports dietitian and psychologist may help. Further reading Burke, L. 1995, ‘Food For Sports Performance’. Allen and Unwin Cox, G. 2006, ‘Making weight in sports- practice tips’, in Clinical Sports Nutrition, (Burke, L and Deakin, V), pp: 196. McGraw-Hill Australia Pty Ltd. O’Connor, H and Caterson, I. 2006, ‘Weight control and the athlete’, in Clinical Sports Nutrition, (Burke, L and Deakin, V), pp: 135-165. McGraw-Hill Australia Pty Ltd. Tarnapolsky, M. 2006, ‘Protein and amino acids for training needs and bulking up’, in Clinical Sports Nutrition, (Burke, L and Deakin, V), pp: 73-103. McGraw-Hill Australia Pty Ltd. Page 4 of 4