Nutritional Intake, Dietary Habits, and. pre-olympic Amateur Boxers Team

Transcription

1 Nutritional Intake, Dietary Habits, and Physiological profile of 2004 Greek pre-olympic Amateur Boxers Team JEREMY E. SIMATOS Dietitian - Sports Nutritionist of Greek National Amateur Boxing Team Director, Hellenic Sports Nutrition Research Institute

2 A B S T R A C T Aim of the Study : The purpose of this study was to record the nutritional intake, and to evaluate the dietary habits of 10 elite level 2004 Greek pre-olympic team male amateur boxers, three months earlier than Athens Olympic Games. Results : Seven day weighed food records showed the mean daily energy intake was 2606 ± 367 kcal/day (36 kcal/kg bw). The main findings are a relatively high fat intake, and the estimated energy, carbohydrate, and protein intakes were lower than the recommended values for athletes. The boxers did not meet the RDI s for a number of micronutrients. None of the athletes had adequate intakes of all micronutrients. Mean percentage body fat of male boxers was 10.1 ± 3.2 (range %). Of the boxers, 90 % used a variety of methods to make weight, including : saunas, hot baths, use of laxatives, skip meals, and the severe energy and fluid restriction. In spite of current athletes general practice, none of the boxers used nutritio- nal ergogenic supplements. Conclusions : The main findings of a study are a high fat intake and low intakes of several micronutrients of 2004 Greek pre-olympic team male amateur boxers. Depending on energy expenditure levels, energy and nutrition intakes may put some elite amateur boxers at risk for severe nutritional deficiencies and compro- mised performance KEY WORDS : boxing, energy balance, dietary intakes, elite athletes, weight control

3 Introduction Boxing is a dynamic sport, which requires high-level physical condition, technical skill, reaction time, tactical efficiency, strength and speed of movement. It also demands a combination of both aerobic and anaerobic energy metabolism, and especially, enormous reserve amounts of individual anaerobic and aerobic power. Success in this highly competitive sport requires exceptional self discipline, and focus as well as close attention to body weight. The competitive performance for both Olympic and amateur boxers has to last 11 min and it is structured on 4 rounds (4x2 minute) with a 1-min rest periods (5,10,16,19). Proper nutritional intake and dietary habits of elite athletes is a very significant and determinant factor to athletic optimal performance. Elite athletes have increased energy needs because of their strenuous training in order to maximize their performance. What a boxer eats and drinks directly affects his energy, strength and ability to last and perform well for the entire bout. A healthy boxer feels better, trains harder, recovers more quickly (replaces the lost energy), and is less susceptible to injury and illness. Optimum nutrition is the result of daily, regular food choices. It is not achieved only by the pregame meal or by eating special foods the last few days before a competition. A well-planned diet can enable the boxer to maintain his ideal or optimum weight on a regular basis so that dieting and extreme weight reduction measures are not become a common practice before competitions (14,17,19). There are many myths and misconceptions about nutrition and its influence and impact on boxing. It is very important, therefore, current scientific and accurate information to be understood and applied as part of the training program

4 Boxers often attempt to gain advantage over opponents by competing in a lighter weight class than their normal body weight, thus they train at a heavier weight and use extreme weight loss measures to make a lower weight for competition. Often they end up competing against someone who has done the same (6,10,17,19). Numerous techniques have been used by athletes to rapidly reduce their weight, such as increased exercise, skipping meals (most commonly breakfast), inducing vomiting, voluntary water restriction, exercising in a rubberized suit, sitting in a sauna or a steambath as well as various combinations of these techniques. Also, athletes may have taken laxatives, diuretics (water pills) and using cathartics (enemas). Rapid and excessive weight loss that leads to dehydration and/or glycogen (carbohydrate) depletion can prevent the boxer from performing his best and put him at a severe disadvantage (2,6,8,15-17,19). No one nutritional research is now available about the dietary practices of amateur boxers. The purpose of this descriptive study was to determine the dietary intake, nutritional status, and eating behaviors of the male 2004 Greek pre-olympic team amateur boxers. No national elite level athletes studies have been published on the dietary habits / practices of amateur boxers and particularly in Greece

5 Methods The subjects were ten (10) elite level 2004 Greek pre Olympic team male amateur boxers, all members of the Hellenic National Team, mean age 23.6 ± 2.4 (range yr). All subjects completed an extensive activity and medical history questionnaire. Anthropometric measurements were taken in the morning, before training, and prior breakfast. Weight and height were measured using a scale and a well-mounted stadiometer to the nearest 0,02 kg and 0,1 cm respectively. Percent body fat was calculated using the sum of seven skinfolds measures (9) with Lange caliper. Body fat-free weight was computed by subtracting the value for fat mass from body weight. Nutritional status was assessed using dietary history and a 7-day weighed food records. All subjects kept weighed dietary records for seven consecutive days which represented a typical training week. Participants were given basic detailed instructions on how to complete food records in the course of a group educational session. Also, regarding their specific needs, practical dietetic written recommendations (how to weigh food intake using standard household measures) were given from the author. Food record data was analyzed using the USDA database (www. nal.usda. gov / fnic) and the Trichopoulou database of Greek food and recipes (18). None of the athletes had a history of diabetes mellitus or other chronic health problems. Also, none of them reported a history of using anabolic steroids, growth hormone, or medication

6 Descriptive characteristics of the subjects are expressed as mean values ( ± Standard Deviations). Results Physical, and physiological characteristics of the boxers are shown in Table 1. They started boxing at the age of 14.5 years (± 2.4), with an average of 8.5 (±3.2) years experience of competitive boxing. Boxers reported practicing 6 days of trai- ning per week (4 h / day). Mean percentage body fat of male boxers was 10.1 ± 3.2 (range %) which was considered to be desirable for adult athletes. Nutrient analysis of 7-day weighed food records is shown in Table 2. The overall reported daily energy intake was 2606 ± 267 kcal. 100 % of boxers had daily fat intake > 35 % of total energy and carbohydrate < 5.5 g/kg bw/day respectively. Carbohydrates consumption, expressed in terms of grams per kg of body weight, was only 4 g/kg which is far less than the suggested amount. The qualitative dietary composition of the athletes was characterized by higher energy intake from lipids. The major sources of fats were hamburgers, fried chips, beef (chopped meat), fried chicken, biscuits, and high-fat, high-sugar, high-salt packed snacks. The boxers did not meet the required RDI s for a number of micronutrients so the present study confirms a low micronutrient intakes of folate, calcium, zinc, magnesium, and vitamin E. None of the athletes had adequate intakes of all micronutrients. More than half of the subjects consumed less than 67 % of the RDI s for folate, calcium and vitamin E

7 Only two boxers (20 %) took breakfast everyday. Eighty percent (80 %) of boxers consumed coffee with a mean intake of 1,5 ± 0,3 cups per day. In spite of current athletes general practice none of the boxers used nutritional ergogenic aids. Three of them (30%) occasionally took a multimineral supplements daily and these supplements were excluded from the nutrient analysis. The most common method used by boxers to rapidly lose weight in preparation for bout was severe energy and fluid restriction for several days (70 %). All boxers stated the use of dieting as a strategy for weight reduction particularly in the week leading to championship competition (at least one day before the official weigh-in). None of the boxers reported seeking professional advice from either dietitians or general practitioners

8 Discussion Sound nutritional practices are critically important for achieving top athletic performance and optimal growth and development (14). The results of the study indicate that international level Greek male amateur boxers have energy and nutrient intakes that place them at risk for nutritional deficiencies and compromised performance. The overall reported daily energy intake was 2606 ± 267 kcal, but it was below the recommended intakes in comparison to high levels of energy expenditure (1) according to 6 days of training per week (4 h/day). Probably, most boxers were on negative energy balance, given the training regimen of these athletes. One of the main errors associated with food records is under-reporting of energy intake during the study period. Indeed, under-reporting is an important and actual problem affecting dietary assessment investigations. The prevalence of underreporting in the present study is difficult to be determined since underreporting appears to be subconscious in nature. Nevertheless, prolonged suboptimal energy and nutrient intakes place the boxer at risk for serious health and performance hazards. Loss of lean muscle mass and altered metabolism are among the consequences of self-imposed food restriction. Severe calorie restriction results in inadequate protein intake. Since the body will always meet energy needs first, the protein will be used for energy sources before it is used for muscle development and repair. All of these changes can lead to fatigue, reduced endurance and exhaustion (2,3,12,14 16)

9 It is generally recommended that athletes should consume a diet rich in carbohydrates (at least 50 to 55 % of total energy) and low in fat ( 30 % of energy intake) (14). None of the boxers that participated in this study met these recommenddations. Dietary assessment of boxers demonstrates low carbodydrate intakes that are insufficient for adequate glycogen resynthesis maintaining optimal muscle glycogen stores during repetitive days of training. Also, all of the above athletes had higher fat contribution in energy intake than recommended. Chronic higher quantities of fat consumption has been associated with lower performance and lower plasma glucose utilization (12,14). The lower than recommended intakes of milk, vegetables, fruits, and grain products by the male boxers could have influenced their mineral intake, especially calcium, magnesium and zinc. These athletes need to increase their consumption of vegetables, fruits, milk and milk products to maintain an adequate long-term essential micronutrient status (4,11,14). Our findings are consistent with other (6,16) which reported that amateur boxers reduce their weight by 2 3 kg in the week leading to championship competition (from their training weight in order to make their championship weight). Only one (1) boxer avoided the constant war against weight, and boxers have been known to use a number of practices in order to make weight, including rapid weight loss through unhealthy methods. A number of studies have shown the detrimental effects of such practices amongst athletes, particularly those competing in weight category sports, such as wrestling, weightlifting and boxing. Possible adverse consequences include impairment of performance, compromised physic

10 cal and mental health (increased anger, fatigue, tension, negative mood, and reduce vigour) and impediment of normal growth and development (2,3,6,8,14-17,19). All boxers interviewed reported that they have more power, endurance, and speed for competition if they reduce their best competitive weight (when fully hydrated) early in the season (performed better having reduced weight) and remain at that weight throughout the season. After considerating these points, (a) adequate fluid balance has the greatest impact on a boxer s training and performance, (b) maintaining a boxer s weight close to his competitive weight may help overcome some of the negative effects of rapid weight loss. With as little as 2 to 3 percent of the body s weight lost as sweat (for a 70 kg boxer that would be 1,5 2 kg), performance can be dropped and concentration, coordination, strength and stamina can be decreased. More importantly, if lost water is not replaced, the body begins to conserve water by slowing down the sweating ; thus the cooling process slows down as well. The body cannot adapt to dehydration. Sweat losses of certain macrominerals, such as magnesium (Mg), iron (Fe), and zinc (Zn), cannot be ignored (2,8,15-17). Although an unrestricted, well-balanced diet will likely prevent the development of mineral deficiencies in most athletes, the use of daily multivitamin / mineral supplement containing no more than the RDI s is not discouraged because high sweat losses may increase the requirement of selected minerals

11 Concluding Remarks (1) Elite level amateur boxers that participated in this study, probably were not in energy balance. The outcomes of this study indicate that there is a need for providing nutritional information to the boxers in Greece. It is important, therefore, current scientific and accurate information to be understood and applied as part of the training program. However, we cannot forget the fact that this sport is categorized in weight classes and that the representative values (for each weight class) vary. (2) More attention should be given by coaches, sports nutritionists, health professionals and physicians to enhance sport nutrition education and to minimize dehydration and dangerous weight control practices among boxers. There is a need to develop dietary intervention and educational programs targeted at promoting optimal nutrient and fluid intakes by these athletes to maintain performance and improve long-term health status (Table 3). (3) An investigation of the effects of different nutritional treatments on the boxer s recovery (between the time of the official weigh-in and competition) may be warranted and useful for helping these athletes prepare for competition. (4) Having a nutritionist accessible on a regular basis for monitoring the weight and modificating the meal plans for each athlete (individualized, specific approach) during all phases of the season is most beneficial. Encouraging athletes to base their diets on nutrient dense high carbohydrate foods, while getting adequate, but not excessive, protein and fat will best accomplish the balanced nutrition that these athletes require during training and competition

12 Acknowledgements This study was supported by the Hellenic Boxing Federation. The author gratefully acknowledge the participation of the athletes for their cooperation in this study

13 References 1. Ainsworth B., Haskell W., Leon A. Compendium of physical activities : Classification of the energy costs of human physical activities. Med. Sci. Sports Exerc.1993; 25: American College of Sports Medicine. Position stand on exercise and fluid replacement. Med. Sci. Sports Exerc. 1996;28:i vii 3. Brownell K., Rodin J.. Eating, Body Weight and Performance in Athletes. Philadelphia, PA : Lea & Febiger, Clarkson P.M., Haymes E.M.. Exercise and mineral status of athletes : calcium, magnesium, phosphorous, and iron. Med. Sci. Sports Exerc. 1995;27: Guidetti L., Musulin A., Baldari C.. Physiological factors in middleweight boxing performance. J. Sports Med. Phys. Fitness 2002;42 : Hall C.J., Lane A.M.. Effects of rapid weight loss on mood and performance among amateur Boxers. Br. J. Sports Med. 2001;35 : Heyward V.H. (Ed.). Advances Fitness Assessment and Exercise Prescription. Champaign, IL : Human Kinetics, Horswill C.A. Weight loss and weight cycling in amateur Wrestlers : Implications for performance and RMR. Int. J. Sport Nutr. 1993;3 : Jackson A., Pollock M.L.. Practical assessment of body composition. Physician Sportsmed. 1985;13: Jako P. (Ed.). Association Internationale De Boxe Amateur Medical Commission Handbook. 5 th ed. Berlin : AIBA, Maughan R.J. Role of micronutrients in sport and physical activity. Br. Med. Bull. 1999;55 : McMurray R.G., Proctor C.R., Wilson W.L.. Effect of caloric deficit and dietary manipulation on aerobic and anaerobic exercise. Int. J. Sports Med. 1991;12 : Monteiro L., Medeiros H. Physiological profile of elite Judokas. Proceedings of the VIIth IOC Olympic World Congress on Sport Sciences. Athens, Greece 7-11 Oct Rosenbloom C.A. (Ed.). Sports Nutrition : A Guide for the Professional Working with Active People. 3 rd ed. Chicago, IL: ADA Publ., Sawka M.N., Pandolf K.B.. Effects of body water loss on physiological function and exercise performance. In: Perspectives in Exercise Science and Sports Medicine (Volume 3). Fluid Homeostasis during Exercise, C.V. Gisolfi and D.R. Lamb (Eds). Carmel, IN : Benchmark Press, 1990, pp. 1-31

14 16. Smith M. Fluid balance in weight categorized sports. Coaching 1996;8 : Smith M., Dyson T., Hale M., Hamilton J., Wellington P. The effects of restricted energy and fluid intake on simulated amateur Boxing performance. Int. J. Sport Nutr. Exerc. Metabol. 2001;11 : Trichopoulou, A. Tables of Food Composition and Composition of Greek Cooked Food and Dishes. Athens, Greece : Trichopoulou, United States Amateur Boxing. Coaching Olympic Style Boxing. Traverse City, MI : Cooper Publishing Group, 1995.

15 TABLE 2. Nutrient analysis of 7-day weighed food records. Values expressed as mean daily intake ( ± SD) Recommended Daily Intake Energy Intake (kcal / day) 2606 (± 267) --- % E, CHO 44,7 (± 5,2) % % E, FAT 42,5 (± 6,4) % % E, PRO 12,8 (± 4,6) % Carbohydrate intake (g/kg bw) 4,01 (± 1,1) > 6 g/kg Fat intake (g/kg bw) 1,71 (± 0,3) 1 g/kg Protein intake (g/kg bw) 1,14 (± 0,2) 1,2 g/kg Dietary fiber (g) 12,8 (± 4,1) 20 g or 10 g/1000 kcal RDI s ( % ) Calcium (mg) 607 ± ,7 Iron (mg) 9,4 ± 3, Zinc (mg) 7,3 ± 1, ,4 Magnesium (mg) 268 ± Folate (μg) 194 ± ,5 Thiamin (mg) 1,2 ± 0,3 1,2 100 Riboflavin (mg) 1,4 ± 0,2 1,3 108 Niacin (mg NE) 16,3 ± 3, Vitamin B6 (mg) 1,4 ± 0,4 1,3 108 Vitamin B12 (μg) 2,2 ± 0,6 2,4 91,6 Vitamin C (mg) 115 ± Vitamin E (mg) 8,7 ± 3,

16 TABLE 3. Fluid and carbohydrate needs of Boxers RATIONALE CARBOHYDRATE (gr) FLUID (cups) For Boxers who train hard daily cups / day High and need to > 7 gr / kg body weight daily (2,5 3 liters) Intensity maximize daily plus fluids before, Training muscle glycogen during, and after recovery exercise To enhance 1 g / kg body weight 1 hour before 2 cups (1/2 liter) Before fuel availability or non-caffeinated, Exercise and 2 g / kg body weight 2 hours before non-alcoholic prehydrate for or 2 hours before a practice 3 g / kg body weight 3 hours before exercise To provide an During additional source At least Exercise of carbohydrate gr / hour ml > 1 h fuel during moderate every 15 minutes and high-intensity to replace sweat boxing practice losses To speed early 1 1,5 gr / kg body weight recovery and high-glycemic CHO beverages ~ 6 cups Recovery rehydration after and foods immediately following per kg of body hard training exercise and every 2 hours after. weight lost especially during Total CHO intake over the next during exercise the season 24 hours at 7 gr / kg (> 450 gr/day)