Combat sports (such as boxing, wrestling, judo, and taekwondo) are categorized into a series of weight classes that are intended to promote fair competition by matching opponents of equal stature and body mass (commonly referred to as “weight” within the sport). Combat sports are usually steeped in their own tradition and culture, particularly in relation to weight-making practices (48). Typically, combat athletes aim to compete at the lightest weight possible in the belief that it will result in a competitive edge over opponents. Consequently, many athletes achieve their target weight via the combination of acute and chronic means that involves severe energy restriction and dehydration (23,24,38,48). The latter weight-making method is common in the days preceding the weigh-in and is known in combat sports as “drying out.”
Although data concerning weight-making practices of combat sports are beginning to accumulate, weight making in combat athletes is still a largely underresearched area. The lack of data on this topic may be because of associated difficulties with researching this population, such as lack of consistent weight-making practices, distrust of nonfamiliar researchers by both athletes and coaches, and moreover, athletes not wanting to openly disclose their habitual weight-making routines to public scrutiny.
Not only do exercise scientists require a greater understanding of the habitual practices that combat athletes typically undertake, but we also need to systematically test the efficacy of alternative scientific-based approaches in terms of both making weight and their resulting impact on performance. A much wider research base will surely lead to improved athlete and coach education, which ultimately, can only improve athlete well-being and enhance performance. In those cases where weight-making practices have been documented, weight losses of 3–4 kg are not uncommon in the week preceding competition (1,2,25,32,53). Such levels of acute weight loss can impair components of sport-specific performance, such as reduced punching force (70) and cognitive function (14), whereas the effects of dehydration and energy restriction carry obvious health risks, including hypoglycemia (14). Indeed, the reduction in energy and fluid intake during training and in the days before competition may increase the risk of infection and impair mood (14), whereas the increased cardiovascular and thermoregulatory strain may result in severe injury and in extreme cases cause death (13).
With this in mind, the aim of the present article is to offer some potential strategies to make weight using a more gradual and scientific approach, which is based on key principles of exercise metabolism and nutrition. We begin by presenting an overview of weight classifications of popular combat sports, followed by a summary of those practices that athletes in combat sports commonly adopt to make weight. After providing commentary on guidelines to make weight that are based on an understanding of how timing, composition, and quantity of energy intake affect metabolic regulation, we close by presenting data from a recently published case study (48). Not only do we hope that these guidelines will help improve practice, but we also aim to stimulate interest among readers to conduct further research in the area.
OVERVIEW OF WEIGHT CLASSIFICATIONS IN COMBAT SPORTS
The main weight classifications of the common combat sports are shown in Table 1. For the amateur combat sports, data were taken from the International Olympic Committee and relevant world governing bodies. In the case of professional boxing, we have used information from the World Boxing Council, given that it is recognized within the sport as the most prestigious governing body. It is noteworthy that in sports such as taekwondo and wrestling, there can be up to 10-kg differences between weight divisions in contrast to professional/amateur boxing where weight divisions are separated by no more than 3–4 kg. Such large differences between consecutive divisions highlight the potential for the introduction of more closely aligned weight categories so as to improve health and safety standards within the sport.
COMMON ATHLETE APPROACHES TO MAKING WEIGHT
To offer insight in this area, we performed literature searches combining key terms such as “weight loss” and “combat sports” as well as individual sport names using relevant databases (e.g., PubMed, MedLine, Web of Science). Because of space constraints, it is not possible to review all the relevant literature in this area. However, contemporary articles that we considered the most informative are summarized in Table 2. The consistency of approach used to summarize the findings differs between articles because of methodological differences between studies. Nevertheless, as expected from the culture of weight-making sports, common approaches to making weight included skipping meals, fasting, saunas, sweat suits, laxatives, diuretics, diet pills, and vomiting. These weight loss strategies are prevalent across all the combat sports examined and are not just specific to certain sports.
GUIDELINES TO MAKING WEIGHT
ASSESSMENT OF BODY COMPOSITION, RESTING METABOLIC RATE, AND DAILY TRAINING ENERGY EXPENDITURE
As with any intervention, the first stage should always be to conduct a sound athlete assessment that is based on reliable and valid assessment tools. Although dual-energy x-ray absorptiometry is now beginning to replace hydrodensitometry as the reference method for studies of body composition in athletic populations (59), a limitation of this technique is its expense and exposure to low-dose ionizing radiation. In a sporting context, therefore, more practical methods, such as skinfold assessments and subsequent use of prediction equations to estimate percent body fat and lean body mass, are more commonly employed (21,22,59,60).
Practitioners should be aware of the limitations of these equations (59), however. In fact, a potential avenue for future research is to develop reliable and valid prediction equations specifically for combat athletes similar to those developed for other sports, such as soccer (59). Given that direct measurement of resting metabolic rate (RMR) is not always practical, it is a common practice to estimate RMR on the basis of prediction equations. The equation of Cunningham (17) has been validated for athletic populations, where RMR = (lean body mass in kg × 22) + 500.
It is also important to estimate the typical daily training expenditure, and in this instance, measurements of heart rate provide the most user-friendly method (27). Having obtained relevant baseline physiological data, dietary analysis should then be conducted by a suitably qualified individual so as to identify nutritional habits that can be improved. Only then can a sound nutritional and conditioning program be developed to attempt to attain the target weight loss in the relevant period. It is difficult to provide precise recommendations in the present article because every athlete will present a different scenario. Nevertheless, we advise a daily energy intake that is at least equivalent to RMR (and as discussed in later sections, an increased protein intake) and a target weight loss of 1–1.5 kg/wk so as to avoid any loss of lean mass and decline in RMR (9,71).
OVERVIEW OF METABOLIC REGULATION IN EXERCISE AND FEEDING
The regulation of substrate utilization during exercise and feeding is a long-standing research area among biochemists. In contrast to the traditional glucose-fatty acid cycle (58), it is now generally accepted that fat oxidation during exercise is largely controlled by carbohydrate (CHO) availability given that insulin attenuates lipolysis so much so that it appears to limit fat oxidation (34). Furthermore, the suppressive effect of pre-exercise CHO ingestion on rates of lipolysis and lipid oxidation can persist for up to 4 hours after a meal (46). In this regard, ingestion of CHO, which ranks low to moderate on the glycemic index (and thus induces a low insulin response), does not attenuate lipolysis and lipid oxidation as much as those CHOs that are high glycemic (83).
In addition to pre-exercise feeding, it is also important to appreciate basic substrate utilization during exercise of varying intensities and duration. Early studies using stable isotope methodology demonstrated that lipid oxidation is reduced, whereas CHO utilization predominates at intensities above 65% o2max (62,77). Moreover, as exercise of moderate intensity becomes more prolonged, there is an increased reliance on plasma free fatty acids derived from adipose tissue lipolysis and reduced reliance on CHO sources (62). The precise cellular mechanisms regulating this shift in substrate utilization are beyond the scope of this review. In brief, evidence suggests that the increased glycolytic flux associated with high-intensity exercise limits the availability of free carnitine, which in turn reduces the activity of carnitine palmitoyl transferase (CPT1), the rate-limiting enzyme for transport of long-chain fatty acids (LCFAs) across the mitochondrial membrane (77).
Similarly, when rates of glycolytic flux are reduced, such as when muscle glycogen availability is progressively reduced during prolonged exercise, free carnitine availability is not as drastically compromised, and consequently, LCFAs are more readily transported into the mitochondria for oxidation (61). Although lipid oxidation appears to be increased in conditions of reduced CHO availability, it is important to note that amino acid oxidation also increased (43). Over time, this may lead to a loss of lean mass (35,45), which would likely be disadvantageous for the combat athlete (given the role of lean body mass in generating force), unless of course (and although not advised) the athlete is required to lose muscle mass to make the target weight class (48).
Finally, it is also important to note that fat storage in the postprandial period is increased with successive meals throughout the day (63). Such findings are likely because of the accumulation of successive insulin increases, increased esterification, and increased lipoprotein lipase activity such that adipose tissue becomes primed for storage (as opposed to hydrolysis) of fat as the day progresses. As a result, fat storage after a meal is greatest in the hours after the evening dinner meal when compared with breakfast and lunch (63). To compensate for this effect, it is advised that the training load is spread out over 2–3 sessions per day, as opposed to a single session of longer duration, so that there is continual interplay between substrate utilization and storage. In practice, this is often structured as an early morning run designated for fat burning, a late morning/early afternoon sport-specific technique/fitness session, and an early evening strength and conditioning session (48).
BASIC NUTRITION AND HYDRATION PRINCIPLES IN MAKING WEIGHT
In considering the information presented above, it appears that timing, quantity, and composition of the macronutrient intake are all critical factors to consider when devising weight-making strategies. Nutritional practices should therefore be devised according to the structure of the daily training sessions so as to maximize the capacity for lipid oxidation during both exercise and recovery while also minimizing fat storage throughout the day.
Logical strategies to implement therefore initially center on a diet that is based around reduced (but we stress not zero) carbohydrate intake (given the role of CHO in regulating lipid metabolism), especially as the day progresses and also reduced saturated fat intake. In fact, there is now a growing body of literature from our laboratory and others demonstrating that training in conditions of reduced CHO availability actually enhances the oxidative capacity of skeletal muscle (47,85), as opposed to traditional guidelines surmising that daily training should be supported with high CHO intake.
When CHO is consumed, it is recommended that it is low glycemic, and in the case of pre-exercise, CHO ingestion, approximately 3 hours before exercise, is advised so as to minimize the suppressive effect of insulin on lipolysis. With the combination of intense training and reduced CHO intake, it is likely that many training sessions will be commenced with muscle glycogen stores that are not considered full or optimal for the energy requirements of the particular session. Given the capacity for such conditions to increase amino acid oxidation, it follows that the daily diet should increase protein intake so as to maintain (or at least minimize) any associated lean mass loss by maintaining the amino acid pool. In fact, we (48) and others (45) have shown that elevated daily protein intake can maintain lean mass even in the face of high daily training energy expenditure and when total daily CHO intake is reduced.
Where protein supplements are being used to support daily protein intake, it is also worth using a supplement that is both casein and whey based so as to minimize the suppressive effects of insulin on lipolysis (given that casein exerts a less pronounced insulin response than whey) (76) as well as increase feelings of satiety by inducing a prolonged feeding effect (33).
When considering the timing of training sessions, performing sessions solely dedicated to the purpose of fat burning are best performed in the early morning after an overnight fast and at moderate intensity and duration (34). In this way, the negative effects of pre-exercise meal ingestion (i.e., high plasma insulin concentrations) and high exercise intensities (i.e., high glycolytic flux limiting LCFA transport) are negated and the exercise stimulus is more closely aligned to maximizing lipid oxidation. In fact, recent data have suggested that fasted training (i.e., training before breakfast), as opposed to training after breakfast, enhances training-induced adaptations of skeletal muscle and may improve insulin sensitivity (78,79). Furthermore, data also demonstrate that fat oxidation was reduced by 30% during an 8-hour recovery period when CHO was ingested before exercise, as opposed to that ingested after exercise (64). For those sessions that are more dedicated to developing technique and sport-specific fitness (and hence are usually of much greater intensity), it is best to undertake them at least in the early morning, late afternoon, or evening time so that some liver and muscle glycogen is available (albeit not considered full) as a result of breakfast, lunch, and dinner ingestion, respectively. In such situations, it is again important to maximize potential lipid oxidation (despite the high exercise intensity) by attempting, if possible, to ensure that the last meal ingested before exercise is done several hours before and is always low glycemic.
It is difficult to provide exact recommendations in terms of the amount and percentage contribution of each macronutrient toward total energy intake that should be consumed. This is especially true considering the importance of individualized recommendations given that every athlete presents a different scenario in terms of RMR, target weight loss, daily training energy expenditure, time to achieve target weight, and so on. As documented earlier, a sound athlete assessment is the first stage that should be undertaken before devising and implementing any intervention. Indeed, in our experience, we have achieved success with daily CHO and fat intake varying from 2 to 5 and 0.5–1 g/kg body mass, respectively. Although current guidelines for daily protein intake are often controversial, in the case of making weight, we usually advise 2–2.5 g/kg body mass owing to the requirement to maintain lean mass in the face of daily energy deficits.
In considering the culture of combat sports where athletes tend to use weight-making methods relying on acute and chronic dehydration, emphasis needs to be placed on coach and athlete education so as to develop a training culture that promotes hydration before, during, and after training. In this regard, performing regular but simple measures of hydration status (such as monitoring training-induced acute weight loss, urine color and osmolality, and hemoglobin and hematocrit status) as well as monitoring habitual drinking patterns are useful educational tools to change athlete and coach perceptions. In instances such as professional boxing where there is typically >24 hours between the weigh-in and competition, an intentional dehydration-induced weight loss in the hours preceding the weigh-in may not be that problematic in terms of health or performance decrements. However, such instances should be carefully supervised by suitably qualified personnel so as to ensure that athlete safety and appropriate refueling and hydration strategies are administered. In combat sports where competition proceeds weigh-in by several hours, acute dehydration may not be appropriate as the short timescale may not allow for optimal refueling and hydration, which could therefore result in impaired performance (14,70). Further research to establish safe levels of acute dehydration in terms of athlete safety and impacting performance is required before definitive guidelines can be provided.
Finally, when devising nutritional and training interventions for combat athletes that simultaneously make weight, improve fitness and develop technique, limiting factors are often the structure of the athlete's day in terms of when coaches schedule training sessions and also whether the athlete is full-time or alternatively, have other daily commitments related to employment and family responsibilities, etc. Considering such limitations, effective communication and a multidisciplinary approach among support staff (e.g., the technical coach, strength and conditioning coach, sports nutritionist) are required so as to develop the best-case scenario in relation to the particular athlete.
POTENTIAL DIETARY SUPPLEMENTS DURING WEIGHT LOSS
In addition to the nutritional strategies described above, there are also a number of supplemental strategies that may help to aid weight loss and perhaps more importantly maintain immune function during times of intense training when energy availability is reduced. The latter is particularly important for those athletes whose dietary preferences may prevent them from obtaining key macro- and micronutrients from food choices per se. Unfortunately, empirical evidence supporting these supplements, especially in athletic populations, is limited, and practitioners are often left to base their decisions on anecdotal reports. A review of potential supplements is shown in Table 3.
CASE STUDY FROM PRACTICE
On the basis of the principles described herein, we have recently published a case study account (48) outlining a nutritional and conditional strategy designed to help a male professional featherweight boxer (57 kg) make weight for a new weight division of super featherweight (59 kg). Over a 12-week period, the client athlete adhered to a daily diet approximately equivalent to his RMR (6–7 MJ; 40% CHO, 38% protein, and 22% fat). Average body mass loss was 0.9 ± 0.4 kg/wk, equating to a total loss of 9.4 kg. This weight loss resulted in a decrease in percent body fat from 12.1 to 7.0% (Figure). In the 30 hours between weigh-in and competition, the client consumed a high-CHO diet (12 g/kg body mass) supported by appropriate hydration strategies and subsequently entered the ring at a fighting weight of 63.2 kg.
This nutritional strategy represented a major change to the athlete's habitual weight-making practices and did not rely on any form of intended dehydration during the training period or preceding weighing-in. However, in this instance, it was evident after baseline assessment that the athlete would have to lose muscle mass to make the target weight. Nevertheless, we suspect that this is commonplace for many combat athletes (who do not have scientific input from support staff), but they have never had the knowledge that lean mass will be compromised.
In fact, following continual coach and athlete education, this athlete has now moved up another weight division to lightweight (61.3 kg), 9 lb heavier than when he won his first domestic national title and also held a version of the world featherweight title. With improved food choices when out of training, this particular athlete now reports to the beginning of training camps no more than 5–6 kg over his competitive weight. As such, the target weight is now achieved with greater ease and in a shorter duration. In some instances, we have also used acute intentional dehydration of 1–1.5 kg in the hours preceding weigh-in with no performance decrements or symptoms of ill health.
The present article has attempted to outline how adhering to basic principles of metabolic regulation that emphasize timing, composition, and quantity of energy intake can help inform nutritional and conditioning programs to strategically make weight. Based on these principles, we provide an overview of guidelines in Table 4 where we pay particular attention to timing and composition of meals in relation to the structure of a combat athlete's training day. For illustrative purposes, we base our plan on a professional boxer who may train 3 times per day thought it is important to note that every athlete presents an individual scenario.
In addition to the published case study outlined in the previous section, we have used similar approaches with professional boxers ranging in weight division from flyweight to heavyweight (in the latter case, to change body composition and not necessarily mass) and observed positive results. Essentially, it is through continual education of both coach and athlete and also the willingness of both parties to adopt novel practices, which is crucial to the success of these interventions. Given the lack of research in this area, we consider it vital that similar case study–type accounts from other combat sports are published in the scientific literature. It is only through sharing such information that the safety and performance of combat sport athletes can be enhanced.
1. Alderman BL, Landers DM, Carlson J, and Scott JR. Factors related to rapid weight loss practices among international-style wrestlers. Med Sci Sports Exerc
36: 249–252, 2004.
2. Artioli GG, Scagliusi FB, Polacow VO, Gualano B, Takesian M, Fuchs M, and Lancha Jr AH. Prevalence, magnitude and methods of rapid weight loss among judo
competitors. Med Sci Sports Exerc
42: 436–442, 2010.
3. Badet C and Quero F. The in vitro effect of manuka honeys on growth and adherence of oral bacteria. Anaerobe
17: 19–22, 2011.
4. Barnett C, Costill DL, Vukovich MD, Cole KJ, Goodpaster BH, Trappe SW, and Fink WJ. Effect of L-carnitine supplementation on muscle and blood carnitine content and lactate accumulation during high-intensity sprint cycling. Int J Sport Nutr
4: 280–288, 1994.
5. Bergendiova K, Tibenska E, and Majtan J. Pleuran (beta-glucan from Pleurotus ostreatus) supplementation, cellular immune response and respiratory tract infections in athletes. Eur J Appl Physiol
9: 2033–2040, 2011.
6. Bishop NC, Blannin AK, Walsh NP, Robson PJ, and Gleeson M. Nutritional aspects of immunosuppression in athletes. Sports Med
28: 151–176, 1999.
7. Blankson H, Stakkestad JA, Fagertun H, Thom E, Wadstein J, and Gudmundsen O. Conjugated linoleic acid reduces body fat mass in overweight and obese humans. J Nutr
130: 2943–2948, 2000.
8. Bloomer RJ, Larson DE, Fisher-Wellman KH, Galpin AJ, and Schilling BK. Effect of eicosapentaenoic and docosahexaenoic acid on resting and exercise-induced inflammatory and oxidative stress biomarkers: A randomized, placebo controlled, cross-over study. Lipids Health Dis
8: 36, 2009.
9. Bray GA and Gray DS. Obesity: Part II—Treatment. West J Med
149: 555–571, 1988.
10. Buckley JD, Abbott MJ, Brinkworth GD, and Whyte PB. Bovine colostrum supplementation during endurance running training improves recovery, but not performance. J Sci Med Sport
5: 65–79, 2002.
11. Buckley JD and Howe PR. Anti-obesity effects of long-chain omega-3 polyunsaturated fatty acids. Obes Rev
10: 648–659, 2009.
12. Castell LM and Newsholme EA. The effects of oral glutamine supplementation on athletes after prolonged exhaustive exercise. Nutrition
13: 738–742, 1997.
13. Centers for Disease Control and Prevention. Hyperthermia and dehydration
related deaths associated with intentional rapid weight loss in three collegiate wrestlers. JAMA
279: 824–825, 1998.
14. Choma C, Sforzo G, and Keller H. Impact of rapid weight loss on cognitive function in collegiate wrestlers. Med Sci Sports Exerc
30: 746–749, 1998.
15. Crooks C, Cross ML, Wall C, and Ali A. Effect of bovine colostrum supplementation on respiratory tract mucosal defenses in swimmers. Int J Sport Nutr Exerc Metab
20: 224–235, 2010.
16. Crooks CV, Wall CR, Cross ML, and Rutherfurd-Markwick KJ. The effect of bovine colostrum supplementation on salivary IgA in distance runners. Int J Sport Nutr Exerc Metab
16: 47–64, 2006.
17. Cunningham JJ. A re-analysis of the factors influencing basal metabolic rate in normal adults. Am J Clin Nutr
33: 2372–2374, 1980.
18. Davis JM, Murphy EA, Brown AS, Carmichael MD, Ghaffar A, and Mayer EP. Effects of oat beta-glucan on innate immunity and infection after exercise stress. Med Sci Sports Exerc
36: 1321–1327, 2004.
19. Davis JM, Murphy EA, McClellan JL, Carmichael MD, and Gangemi JD. Quercetin reduces susceptibility to influenza infection following stressful exercise. Am J Physiol Regul Integr Comp Physiol
295: 505–509, 2008.
20. Davison G and Diment BC. Bovine colostrum supplementation attenuates the decrease of salivary lysozyme and enhances the recovery of neutrophil function after prolonged exercise. Br J Nutr
103: 1425–1432, 2010.
21. Durnin JVGA and Womersley J. Body fat assessed from total body density and its estimation from skinfold thicknesses; measurements on 481 men and women aged 16 to 72 years. Br J Sport Nutr
32: 77–97, 1974.
22. Eston RG, Rowlands AV, Charlesworth S, Davies A, and Hoppitt T. Prediction of DXA-determined whole body fat from skinfolds: Importance of including skinfolds from the thigh and calf in young, healthy men and women. Eur J Clin Nutr
59: 695–702, 2005.
23. Filaire E, Maso F, Degoutte F, Jouanel P, and Lac G. Food restriction, performance, psychological state and lipid values in judo
athletes. Int J Sports Med
22: 454–459, 2001.
24. Fleming S and Costarelli V. Nutrient intake and body composition in relation to making weight in young male Taekwondo
players. Nutr Food Sci
37: 358–366, 2007.
25. Fleming S and Costarelli V. Eating behaviours and general practices used by Taekwondo
players in order to make weight before competition. Nutr Food Sci
39: 16–23, 2009.
26. Gardner CD, Kim S, Bersamin A, Dopler-Nelson M, Otten J, Oelrich B, and Cherin R. Micronutrient quality of weight-loss diets that focus on macronutrients: Results from the A TO Z study. Am J Clin Nutr
92: 304–312, 2010.
27. Gilman MB. The use of heart rate to monitor the intensity of endurance training. Sports Med
21: 73–79, 1996.
28. Gleeson M. Dosing and efficacy of glutamine supplementation in human exercise and sport training. J Nutr
138: 2045S–2049S, 2008.
29. Graham TE. Caffeine and exercise: Metabolism, endurance and performance. Sports Med
31: 785–807, 2001.
30. Graham TE, Battram DS, Dela F, El-Sohemy A, and Thong FS. Does caffeine alter muscle carbohydrate and fat metabolism during exercise? Appl Physiol Nutr Metab
33: 1311–1318, 2008.
31. Hall H, Fahlman MM, and Engels HJ. Echinacea purpurea and mucosal immunity. Int J Sports Med
28: 792–797, 2007.
32. Hall CJ and Lane AM. Effects of rapid weight loss on mood and performance among amateur boxers. Br J Sports Med
35: 390–395, 2001.
33. Hochstenbach-Waelen A, Veldhorst MA, Nieuwenhiuzen AG, Westerterp-Plantenga MS, and Westerterp KR. Comparison of 2 diets with either 25 or 10% of energy as casein on energy expenditure, substrate balance and appetite profile. Am J Clin Nutr
89: 831–838, 2009.
34. Horowitz JF, Mora-Rodriguez R, Byerley LO, and Coyle EF. Lipolytic suppression following carbohydrate ingestion limits fat oxidation during exercise. Am J Physiol
273: 768–775, 1997.
35. Howarth KR, Phillips SM, MacDonald MJ, Richards D, Moreau NA, and Gibala MJ. Effect of glycogen availability on human skeletal muscle protein turnover during exercise and recovery. J Appl Physiol
109: 431–438, 2010.
36. Hursel R and Wetserterp-Plantenga MS. Thermogenic ingredients and body weight regulation. Int J Obes (Lond)
34: 659–669, 2010.
37. Ivy JL, Costill DL, Fink WJ, and Lower RW. Influence of caffeine and carbohydrate feedings on endurance performance. Med Sci Sports
11: 6–11, 1979.
38. Kiningham RB and Gorenflo DW. Weight loss methods of high school wrestlers. Med Sci Sports Exerc
33: 810–813, 2001.
39. Koh EH, Lee WJ, Lee SA, Kim EH, Cho EH, Jeong E, Kim DW, Kim MS, Park JY, Park KG, Lee HJ, Lee IK, Lim S, Jang HC, Lee KH, and Lee KU. Effects of alpha-lipoic acid on body weight in obese subjects. Am J Med
124: 85.e1–85.e8, 2011.
40. Kreider RB, Ferreira MP, Greenwood M, Wilson M, and Almada AL. Effects of conjugated linoleic acid supplementation during resistance training on body composition, bone density, strength, and selected hematological markers. J Strength Cond Res
16: 325–334, 2002.
41. Krzywkiwski K, Petersen EW, Ostrowski K, Kristensen JH, Boza J, and Pedersen BK. Effect of glutamine supplementation in exercise induced changes in lymphocyte function. Am J Physiol Cell Physiol
281: C1259–C1265, 2001.
42. Kwakman PH, Te Velde AA, de Boer L, Vandenbroucke-Grauls CM, and Zaat SA. Two major medicinal honeys have different mechanisms of bactericidal activity. PLoS One
6: e17709, 2011.
43. Lemon PWR and Mullin JP. Effect of initial muscle glycogen levels on protein catabolism during exercise. J Appl Physiol
48: 624–629, 1980.
44. Maki KC, Reeves MS, Farmer M, Yasunaga K, Matsuo N, Katsuragi Y, Komikado M, Tokimitsu I, Wilder D, Jones F, Blumberg JB, and Cartwright Y. Green tea catechin consumption enhances exercise-induced abdominal fat loss in overweight and obese adults. J Nutr
139: 264–270, 2009.
45. Mettler S, Mitchell N, and Tipton KD. Increased protein intake reduces lean body mass loss during weight loss in athletes. Med Sci Sports Exerc
42: 326–337, 2009.
46. Montain SJ, Hopper MK, Coggan AR, and Coyle EF. Exercise metabolism at different time intervals after a meal. J Appl Physiol
70: 882–888, 1991.
47. Morton JP, Croft L, Bartlett JD, Maclaren DP, Reilly T, Evans L, McArdle A, and Drust B. Reduced carbohydrate availability does not modulate training-induced heat shock protein adaptations but does up regulate oxidative enzyme activity in human skeletal muscle. J Appl Physiol
106: 1513–1521, 2009.
48. Morton JP, Robertson C, Sutton L, and MacLaren DP. Making the weight: A case study from professional boxing
. Int J Sport Nutr Exerc Metab
20: 80–85, 2010.
49. Murphy EA, Davis JM, Brown AS, Carmichael MD, Ghaffar A, and Mayer EP. Oat beta-glucan effects on neutrophil respiratory burst activity following exercise. Med Sci Sports Exerc
39: 639–644, 2007.
50. Davis JM, Murphy EA, McClellan JL, Carmichael MD, and Gangemi JD. Quercetin reduces illness but not immune perturbations after intensive exercise. Med Sci Sports Exerc
39: 1561–1569, 2007.
51. Nieman DC, Henson DA, McAnulty SR, Jin F, and Maxwell KR. n-3 polyunsaturated fatty acids do not alter immune and inflammation measures in endurance athletes. Int J Sport Nutr Exerc Metab
19: 536–546, 2009.
52. Nieman DC, Henson DA, McMahon M, Wrieden JL, Davis JM, Murphy EA, Gross SJ, McAnulty LS, and Dumke CL. Beta-glucan, immune function, and upper respiratory tract infections in athletes. Med Sci Sports Exerc
40: 1463–1471, 2008.
53. Oppliger RA, Steen SA, and Scott JR. Weight loss practices of college wrestlers. Int J Sport Nutr Exerc Metab
13: 29–46, 2003.
54. Parry-Billings M, Budgett R, Koutedakis Y, Blomstrand E, Brooks S, Williams C, Calder PC, Pilling S, Baigrie R, and Newsholme EA. Plasma amino acid concentrations in the overtraining syndrome: Possible effects on the immune system. Med Sci Sports Exerc
24: 1353–1358, 1992.
55. Pershadsingh HA. Alpha-lipoic acid: Physiologic mechanisms and indications for the treatment of metabolic syndrome. Expert Opin Investig Drugs
16: 291–302, 2007.
56. Rains TM, Agarwal S, and Maki KC. Antiobesity effects of green tea catechins: A mechanistic review. J Nutr Biochem
22: 1–7, 2011.
57. Ramel A, Martinez JA, Kiely M, Bandarra NM, and Thorsdottir I. Moderate consumption of fatty fish reduces diastolic blood pressure in overweight and obese European young adults during energy restriction
26: 168–174, 2010.
58. Randle PJ, Garland PB, Hales CN, and Newsholme EA. The glucose fatty acid cycle: Its role in insulin sensitivity and the metabolic disturbances of diabetes mellitus. Lancet
1: 785–789, 1963.
59. Reilly T, George K, Marfell-Jones M, Scott M, Sutton L, and Wallace J. How well do skinfold equations predict percent body fat in elite soccer players? Int J Sports Med
30: 607–613, 2009.
60. Reilly T, Maughan RJ, and Hardy L. Body fat consensus statement of the steering groups of the British Olympic Association. Sports Exerc Inj
2: 46–49, 1996.
61. Roepstorff C, Halberg N, Hillig T, Saha AK, Ruderman NB, Wojtaszewski JF, Richter EA, and Kiens B. Malonyl-CoA and carnitine in regulation of fat oxidation in human skeletal muscle during exercise. Am J Physiol Endocrinol Metab
288: E133–E142, 2005.
62. Romijn JA, Coyle EF, Sidossis LS, Gastaldelli A, Horowitz JF, Endert E, and Wolfe RR. Regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity and duration. Am J Physiol
265: E380–E391, 1993.
63. Ruge T, Hodson L, Cheeseman J, Dennis AL, Fielding BA, Humphreys SM, Frayn KN, and Karpe F. Fasted to fed trafficking of fatty acids in human adipose tissue reveals a novel regulatory step for enhanced fat storage. J Clin Endocrinol Metab
94: 1781– 1788, 2009.
64. Schneiter P, Di Vetta V, Jequier E, and Tappy L. Effect of physical exercise on glycogen turnover and net substrate utilisation according to the nutritional state. Am J Physiol
269: 1031–1036, 1995.
65. Schoeller DA, Watras AC, and Whigham LD. A meta-analysis of the effects of conjugated linoleic acid on fat-free mass in humans. Appl Physiol Nutr Metab
34: 975–978, 2009.
66. Senchina DS, Hallam JE, Dias AS, and Perera MA. Human blood mononuclear cell in vitro cytokine response before and after two different strenuous exercise bouts in the presence of bloodroot and Echinacea extracts. Blood Cells Mol Dis
43: 298–303, 2009.
67. Shing CM, Hunter DC, and Stevenson LM. Bovine colostrum supplementation and exercise performance: Potential mechanisms. Sports Med
39: 1033–1054, 2009.
68. Simopoulos AP. Omega-3 fatty acids and athletics. Curr Sports Med Rep
6: 230–236, 2007.
69. Smedman A and Vessby B. Conjugated linoleic acid supplementation in humans—Metabolic effects. Lipids
36: 773–781, 2001.
70. Smith M, Dyson R, Hale T, Hamilton M, Kelly J, and Wellington P. The effects of restricted energy and fluid intake on simulated amateur boxing
performance. Int J Sport Nutr Exerc Metab
11: 238–247, 2001.
71. Steigler P and Cunliffe A. The role of diet and exercise for the maintenance of fat-free mass and resting metabolic rate during exercise. Sports Med
36: 239–262, 2006.
72. Stephens FB, Constantin-Teodosiu D, Laithwaite D, Simpson EJ, and Greenhaff PL. An acute increase in skeletal muscle carnitine content alters fuel metabolism in resting human skeletal muscle. J Clin Endocrinol Metab
91: 5013–5018, 2006a.
73. Stephens FB, Constantin-Teodosiu D, Laithwaite D, Simpson EJ, and Greenhaff PL. Insulin stimulates L-carnitine accumulation in human skeletal muscle. FASEB J
20: 377–379, 2006b.
74. Stephens FB, Evans CE, Constantin-Teodosiu D, and Greenhaff PL. Carbohydrate ingestion augments L-carnitine retention in humans. J Appl Physiol
102: 1065–1070, 2007.
75. Szolomicki J, Samochowiec L, Wojcicki J, and Drozdzik M. The influence of active components of Eleutherococcus senticosus on cellular defence and physical fitness in man. Phytother Res
14: 30–35, 2000.
76. Tang JE, Moore DR, Kujbida GW, Tarnopolsky MA, and Phillips SM. Ingestion of whey hydrolysate, casein, or soy protein isolate: Effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. J Appl Physiol
107: 987–992, 2009.
77. Van Loon LJ, Greenhaff PL, Constantin-Teodosiu D, Saris WH, and Wagenmakers AJ. The effects of increasing exercise intensity on muscle fuel utilisation in humans. J Physiol
536: 295–304, 2001.
78. Van Proeyen K, Szlufcik K, Nielens H, Pelgrim K, Deldicque L, Hesselink M, Van Veldhoven PP, and Hespel P. Training in the fasted state improve glucose tolerance during fat rich diet. J Physiol
588: 4289–4302, 2010.
79. Van Proeyen K, Szlufcik K, Nielens H, Ramaekers M, and Hespel P. Beneficial metabolic adaptations due to endurance exercise training in the fasted state. J Appl Physiol
110: 236–245, 2011.
80. Venables MC, Hulston CJ, Cox HR, and Jeukendrup AE. Green tea extract ingestion, fat oxidation, and glucose tolerance in healthy humans. Am J Clin Nutr
87: 778–784, 2008.
81. Villani RG, Gannon J, Self M, and Rich PA. L-Carnitine supplementation combined with aerobic training does not promote weight loss in moderately obese women. Int J Sport Nutr Exerc Metab
10: 199–207, 2000.
82. Wallace A, Eady S, Miles M, Martin H, McLachlan A, Rodier M, Willis J, Scott R, and Sutherland J. Demonstrating the safety of manuka honey UMF 20+ in a human clinical trial with healthy individuals. Br J Nutr
103: 1023–1028, 2010.
83. Wee L-S, Williams C, Tsintzas K, and Boobis L. Ingestion of a high glycemic index meal increases muscle glycogen storage at rest but augments its utilization during subsequent exercise. J Appl Physiol
99: 707–714, 2005.
84. Westerterp-Plantenga MS. Green tea catechins, caffeine and body-weight regulation. Physiol Behav
100: 42–46, 2010.
85. Yeo WK, Paton CD, Garnham AP, Burke LM, Carey AL, and Hawley JA. Skeletal muscle adaptation and performance responses to once a day versus twice every second day endurance training regimens. J Appl Physiol
105: 1462–1470, 2008.