NMDS311 Sports Nutrition

Transcription

1 NMDS311 Sports Nutrition Session 5 Weight Making Sports Nutritional Medicine Department

2 Weight Making Sports Sports Nutrition Session 5 Energy metabolism during exercise Benefits and risks of weight loss Challenges and barriers Weight/fat loss methods Endeavour College of Natural Health 2

3 Weight Category Sports SPORT COMPETITION WT CATEGORIES WEIGH-IN Wrestling 3 x 2min rounds Up to 5 bouts/day One day of comp Boxing 3x3min rounds, 1 bout every 2 nd day Judo 5 min bout 4-5 bouts over the day M: 7 wt. divisions between kg F: 7 wt. divisions between 48-72kgs 11 wt. divisions between kg M: 8 wt. divisions between kg F: 7 wt. divisions between kg Single weigh in night before comp Morning of first day of comp + each day an individual fights >3hr before fight Morning of competition (Burke & Deakin, 2015) Endeavour College of Natural Health 3

4 Weight Category Sports SPORT COMPETITION WT CATEGORIES WEIGH-IN Taekwondo Jockeys Olympic Weightlifting 3x3min rounds. 5-6 bouts over the day Can race several days per week, 6-8 rides/day 3 lifts per discipline 2 disciplines One day 4 wt. divisions M: kg F: kg AUS minimum wt. 43.5kg including saddle and accessories. Horses wt. handicapped M: 8 wt. divisions between kg F: 7 wt. divisions between kg Day before No later than 45min before each race. May have to weigh in AFTER as well. Various depending on organisers (usually before) (Burke & Deakin, 2015) Endeavour College of Natural Health 4

5 Weight Category Sports SPORT COMPETITION WT CATEGORIES WEIGH-IN Karate Lightweight rowing M: 3min bout F: 2min bout 6-8 bouts/day 2000m race Multi-race day Multiple Days 5 wt. divisions M: kg F: kg M: 72.5kg single, crew average <70kg F: 59kg single crew average <57kg Cox <55kg (M), <50kg (F) 1-2 hrs before start of competition 1-2 hrs before race start, each day of racing. (Burke & Deakin, 2015) Endeavour College of Natural Health 5

6 Other Considerations At Olympics, often have fewer weight divisions available to compete (especially females) may look to make greater adjustment to body mass in order to compete Some sports compete on a weekly basis during the competitive season Adolescents athletes are still growing and maturing physically which makes setting a weight category at one end of the season more difficult (Burke & Deakin, 2015) Endeavour College of Natural Health 6

7 Other Considerations Anecdotally it would seem many athletes adopt an adhoc approach to monitoring their weight e.g. weighing themselves at different times of day and on different sets of scales, thereby making accurate assessment of progress towards weight targets difficult Further, many also equate weight change which occurs during a training session due to sweat loss, as true weight loss (Australian Institute of Sport, 2010) Endeavour College of Natural Health 7

8 Other Considerations By extension, they will restrict fluid intake during training to induce a greater fluid deficit, which will only compromise training performance, as well as increase susceptibility to opportunistic infection. The most effective strategy to monitor weight is to weigh at the same time of day, on the same set of scales, preferably first thing in the morning before eating or drinking. Unless an athlete is competing in the next couple of weeks, weighing once a week is appropriate. (Australian Institute of Sport, 2010) Endeavour College of Natural Health 8

9 Minimum Weight In the late 1990 s, the governing body for college sport in the United States, the National College Athletic Association (NCAA), implemented a number of rule changes designed to curb the extent of extreme weight making practices undertaken by collegiate wrestlers, one of which was the introduction of the minimum weight Under this rule, at the start of the pre-season wrestlers have their body fat percentage assessed, which is in turn used to determine the minimum weight at which they are allowed to compete (Australian Institute of Sport, 2010) Endeavour College of Natural Health 9

10 Minimum Weight The minimum weight set is at 5% body fat for men and 12-14% for women Further, wrestlers are allowed only to lose a maximum of 2 pounds a week (~0.9 kg/wk) from the start of the preseason to the date of their competition (Australian Institute of Sport, 2010) Source: Endeavour College of Natural Health 10

11 Assessing an Appropriate Weight Class NCAA Recommendations for Lowest Allowable weight Assess athletes before start of pre-season training Must be hydrated on the day of body composition assessment - Urine Specific Gravity (USG) <1.020 Weigh on calibrated scales Body composition (skinfolds 3 sites: triceps, subscapular, abdominal; BODPOD or hydro densitometry trained measurer), and data put into a specific equation to assess malnutrition (Australian Institute of Sport, 2010) Endeavour College of Natural Health 11

12 Example of Weight Class Guideline A 78 kg male wrestler is assessed as having a % body fat of 7.8% Therefore, his fat free weight is = 78 (78 x 7.8%) = = 71.9kg Minimum weight = 71.91/0.95 = 75.7kg Therefore, this athlete is not allowed to fight in a weight category below 75.7kg (Australian Institute of Sport, 2010) Endeavour College of Natural Health 12

13 Inbuilt Guidelines Prohibit the practice of dehydration, the use of hot rooms, saunas, hot boxes, hot showers, heating devices, vapour impermeable suits (sweat suits), diuretics, emetics, laxatives and self inducing vomiting. Guidelines written by the NCAA to prevent death by severe weight cutting strategies (Australian Institute of Sport, 2010) Endeavour College of Natural Health 13

14 Making Weight Issues Weight often lost rapidly prior to competition Fluid loss or restriction (sauna, rubber suits) Food restriction, fasting Diuretics, laxatives, vomiting Intention is to ensure level playing field Larger athletes still aim to make a lower weight Sports vary in the number of categories available (Burke & Deakin, 2015) Endeavour College of Natural Health 14

15 Making Weight Issues Competitive success Defeat opponent rather than personal best Use strategies to optimise weight regain Negative impact varies depending on sport & weight loss methods used (> energy + fluid restriction) (Burke & Deakin, 2015) Endeavour College of Natural Health 15

16 Making Weight Strategies Dehydration Banned by NCAA for wrestlers Aim for no more than 2% body mass Diet Rapid weight loss Greater loss of lean mass Greater loss in performance Adequate carbohydrate to maintain performance Protein requirement with energy restriction (~1.2 g/kg) Low residue diet (Burke & Deakin, 2015) Endeavour College of Natural Health 16

17 Making Weight Strategies Acute weight loss strategies Weight loss of 2-3% of a hydrated body mass in the 2-3 days before competition weigh-in should be tolerated by most athletes, especially if employed against a background of good nutrition and hydration practices. Strategies that can be used to achieve this include moderate energy restriction, manipulation of the residue content of the diet and mild restriction of fluid and sodium, combined with appropriate level of training, to achieve mild dehydration. (Australian Institute of Sport, 2010) Endeavour College of Natural Health 17

18 Making Weight Strategies Energy restriction Most athletes taper (or reduce training load) in the two weeks leading into a major competition This reduction in energy expenditure needs to be matched by a drop in energy intake in order to sustain body mass loss leading into competition As with long term weight management, a severe energy restriction at this stage is likely to be counter-productive (Australian Institute of Sport, 2010) Endeavour College of Natural Health 18

19 Making Weight Strategies Low residue diet Switching from a normal dietary intake of moderate/high levels of fibre to a low fibre or residue meal plan can result in an acute body mass loss of 0.5g - 1 kg secondary to a reduction in the weight of the gastrointestinal contents. This strategy will only be effective if undertaken against a background of a training diet that promoted adequate fibre intake. (Australian Institute of Sport, 2010) Endeavour College of Natural Health 19

20 Making Weight Strategies Examples of food changes include changing multigrain to white bread, high fibre cereal to a low fibre cereal, and reducing fruit and vegetable intakes. (Australian Institute of Sport, 2010) Endeavour College of Natural Health 20

21 Making Weight Strategies Manipulation of body water content The creation of a fluid deficit, by deliberately inducing sweat and/or fluid loss from the body, whilst also restricting fluid intake, is one of the most commonly used acute weight making strategies used by athletes. Ideally athletes will aim to induce sweat loss through exercise typically included in their normal training program. (Australian Institute of Sport, 2010) Endeavour College of Natural Health 21

22 Making Weight Strategies This is instead of other methods (e.g. sauna, laxatives, diuretics, blood letting, extra exercise sessions) which can also result in fatigue and potentially have a more adverse effect on health and performance. During this time, athletes should focus on drinking fluids low in salt, such as water, cordial and juice. Drinking these fluids separate to food can help counter the increased fluid retention associated with the natural, or added, salt content of foods. (Australian Institute of Sport, 2010) Endeavour College of Natural Health 22

23 Managing Body Mass Chronic Weight Management Set a plan for Body Weight (BW) management over the off season/pre-season Optimise training capabilities / adaptations, and health (e.g. Don t compromise recovery, periodise CHO to pre/during exercise) Regular assessment of weight and body composition May need to decrease lean muscle mass and well as fat mass to reach desired Wt. (Australian Institute of Sport, 2010) Endeavour College of Natural Health 23

24 Practical Issues Need to optimise training capabilities at the same time as encouraging progressive body fat loss. Should they eat before training? Considerations as to WHEN it is appropriate to consume carbohydrate DURING exercise (Australian Institute of Sport, 2010) Endeavour College of Natural Health 24

25 Practical Issues Not compromising post training recovery by cutting out all CHO, especially when there may be a harder session in the afternoon or if the athlete is feeling particularly tired that day. Development of Strength versus Muscle Mass to increase strength, it doesn t mean muscle mass needs to increase. (Australian Institute of Sport, 2010) Endeavour College of Natural Health 25

26 Class Activity Watch how athletes at Ohio University cut weight on a weekly basis (2:30mins) Endeavour College of Natural Health 26

27 Example of a Low Residue Plan Before training: 1 piece of fruit or White toast with spread During training: (if >90mins) 500ml of Sports Drink or water After Training: 200g of greek yoghurt with 1 TSP of honey or small amount of berries Lunch: Corn thins/2 slices of low fibre bread with 60-70g of protein + salad During training: (if >90mins) 500ml of Sports Drink or water After Training: 200g of greek yoghurt with 1 TSP of honey or small amount of berries Dinner: ½ Cup of rice or 1 small potato with g of protein + small amount of vegetables Endeavour College of Natural Health 27

28 Potential Impact of Making Weight on Performance Increased Rate of Perceived Exertion (RPE) Mood Changes Increased levels of tension, anger and fatigue Impaired cognitive skills and concentration Increased confusion during long/hard training sessions Standard effects of dehydration on performance (reduced thermoregulatory ability, reduced muscular endurance, increased risk of heat stress) (Burke & Deakin, 2015) Endeavour College of Natural Health 28

29 Reducing Fat Mass for Athletes If athletes need to lose body mass to achieve their weight target, they should do so through long term moderate energy restriction and appropriate exercise. A moderate energy deficit ( kj/day) may help athletes achieve a weight loss of up to 0.5 kg/per week. A more marked energy deficit, achieved through severe energy restriction and/or through excessive exercise, will result in a greater loss of lean muscle tissue. (Australian Institute of Sport, 2010) Endeavour College of Natural Health 29

30 Reducing Fat Mass for Athletes This will have a negative effect on power to weight ratio and likely result in a greater rebound in weight once normal eating patterns have resumed. Even when targeting loss of body mass, it is important that athletes still support the demands of training through appropriate nutrient intake. (Australian Institute of Sport, 2010) Endeavour College of Natural Health 30

31 Reducing Fat Mass for Athletes Diets should provide sufficient CHO to fuel the demands of daily training (5-7 g/kg/body mass), with a focus on nutrient-dense options that also contribute to the athlete s targets for other key micronutrients e.g. calcium and iron. Protein needs ( g/kg/body mass) are usually easily met by consuming a mixed diet. The inclusion of a protein source at most meals and snacks will improve satiety, reduce the extent of loss of lean muscle tissue associated with restricted energy diets, and support training adaptations and regeneration of damaged tissues after training. (Australian Institute of Sport, 2010) Endeavour College of Natural Health 31

32 Reducing Fat Mass for Athletes It is common for some athletes looking to reduce the overall energy intake to cut out the sports foods e.g. sports drink, liquid meal supplements, used to support key training sessions. Such a practice may only serve to compromise training quality and increase susceptibility to opportunistic infection. These athletes would be better served by reducing intake of energy-dense, low nutrient foods and fluids e.g. discretionary foods, alcohol, cordial and soft drink. (Australian Institute of Sport, 2010) Endeavour College of Natural Health 32

33 Repeated extreme weight loss long term side effects Micronutrient deficiencies Lowered Resting Metabolic Rate (RMR) Depressed sex hormone concentrations (decreased testosterone, altered menstrual cycle) Reduction in markers of bone synthesis (such as lowered corrected calcium) (Burke & Deakin, 2015) Endeavour College of Natural Health 33

34 Repeated extreme weight loss long term side effects Loss of muscle mass and growth impairment in adolescent athletes (due to continuous negative caloric deficit) Increased risk of disordered body image and disordered eating behaviours (Burke & Deakin, 2015) Endeavour College of Natural Health 34

35 Dangerous Weight Cutting This demonstrates the dangers so athletes go through to cut large amounts of weigh in a short period of time before they weigh in. (27:31mins) o Endeavour College of Natural Health 35

36 Making Weight Low fibre/residue/salt can reduce weight by 0.5-1kg (normally commenced 2-3 days fight day) Fluid restriction: Limit to last 24hrs where possible Where necessary, restrict overall food quantity Mostly main meals/supper night before Most individuals lose weight overnight, which needs to be factored in PRACTICE BEFORE they get to competition! (Burke & Deakin, 2015) Endeavour College of Natural Health 36

37 After Weigh In REHYDRATE! As soon as you can after weigh in Sports Drink / electrolytes help retain fluid better Keep drinking water over rest of day until competition REFUEL! Eat as soon as you can after weigh in Light snack 1-2hrs before each bout in only weigh in once but have sufficient time delays between bouts (Burke & Deakin, 2015) Endeavour College of Natural Health 37

38 Example Guidelines AIS Post weigh in Rowing Fluid: 28.5ml/kg BW Sodium: 33mg/kg BW CHO: 2.3g/kg BW Watch fibre if have been following a low fibre diet Avoid soft drinks and juices as higher sugar concentration may induce diarrhoea (Burke & Deakin, 2015) Endeavour College of Natural Health 38

39 Managing weight for consecutive Weigh-ins Influenced by period between weigh-ins (jockeys can have to weigh in on the day, 3-4times/week, rowing 1-2 days before regatta, combat could be up to 1 week before) Important to recover well after competition (Rehydrate, Refuel, Sleep) (Burke & Deakin, 2015) Endeavour College of Natural Health 39

40 Managing weight for consecutive Weigh-ins The less weight they lose for weigh in, the easier it is to manage long term. IMPORTANT - to try to ensure athletes maintain their weight at 2-3% above fighting weight to ensure weight loss before each fight is easier and does not compromise performance and training. (Burke & Deakin, 2015) Endeavour College of Natural Health 40

41 References Australian Institute of Sport (2010). Making Weight in Weight Category Sports. Retrieved from weight_making_sports Burke L & Deakin V (2015). Clinical sports nutrition, 5 th Ed, McGraw Hill, Sydney. Endeavour College of Natural Health 41

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