CLINICAL INVESTIGATION
Associations Among Dehydration, Testosterone and Stress Hormones in Terms of Body Weight Loss Before Competition _ Yıldırım Irfan, PhD
Abstract: Background: In weight class sports, such as judo, taekwondo and wrestling, reducing body weight before competitions is common. However, it is recommended that weight loss per week should not exceed 1.5% of total body weight otherwise, athletes’ metabolism and endocrine parameters are negatively affected, which will deteriorate their physiology and psychology and thus decrease their performance. The aim of this study was to determine weight loss and hydration levels after weight loss before competitions among the elite wrestlers and to explore the association between hydration levels, and stress and testosterone. Methods: This was an observational study. The study was undertaken with 56 voluntary athletes who participated in wrestling championship. With blood samples taken from the wrestlers, glucose, blood urea nitrogen, sodium (Na), cortisol, prolactin and testosterone hormone analyses were evaluated by a specialist at a biochemical laboratory. Results: It was found out that according to plasma osmolarity levels, there were significant differences between those dehydrated and those who maintained euhydration in terms of cortisol and total testosterone levels (P , 0.001). It was detected that an association was present between plasma osmolarity, and cortisol (r 5 0.667) and total testosterone levels (r 5 20.627) among the elite wrestlers. Conclusions: It was discovered that elite wrestlers were subjected to quick and high level of weight losses before competitions in a very short time (1–5 days). It was seen that their hydration levels differed due to the weight loss, which was explored to be causing acute dehydration among the wrestlers. Key Indexing Terms: Body Weight Loss; Stress; Cortisol; Total Testosterone; Dehydration. [Am J Med Sci 2015;350(2):103–108.]
I
n combat sports, athletes are classified according to their body weights and grouped into competition weights. Weight classes in wrestling, which is one of those combat sports, are 55, 60, 66, 74, 84, 96 and 120 kg. It is obligatory that wrestlers should have a body weight appropriate for the weight classes in which they are going to compete when they are weighed in on the day (between 18.00 and 18.30) before the competition. However, many athletes want to compete in lower weight classes by reducing body mass index due to the idea of competing against opponents who are less strong than them, which is, they think, advantageous. Therefore, reducing body weight before competitions is a commonly used method in weight class sports, such as judo, taekwondo, karate and wrestling. Athletes lose body weight using such inappropriate methods as intense exercises, sauna, nutrition and fluid restriction in a very short time (1–7 days) before the competitions.1–4 In NCAA (Wrestling Weight Certification) it is reported that weight loss per week From the School of Physical Education and Sports, Afyon Kocatepe University, Afyonkarahisar, Turkey. Submitted February 14, 2015; accepted in revised form May 12, 2015. The author has no financial or other conflicts of interest to disclose. This study was presented 4th International Conference on Science Culture and Sport, 22–26 May 2015, Ohrid-Macedonia. _ Correspondence: Irfan Yıldırım, PhD, School of Physical Education and Sports, Afyon Kocatepe University, Afyonkarahisar, Turkey (E-mail: [email protected]).
The American Journal of the Medical Sciences
should not exceed 1.5% of total body weight.3 Otherwise, a short term high level of weight loss will lead to dehydration, which will result in deteriorations in the athletes’ physiology and psychology by causing negative effects on their metabolisms and endocrine parameters and thus their performance will decrease.1–4 Dehydration causes a decrease in plasma volume of the organism, acute cardiovascular disorders (arrhythmia, hypotension, tachycardia), breakdown of thermoregulation, decreased activity of immune system, insufficient distribution of nutrition/ energy resources and slowdown of metabolic wastes in athletes and, as a result, adversely affects their health and performance.2,5–7 Because weight losses generally occur in a shorter time, thanks to some methods in combination with nutrition and fluid restrictions; these losses also have detrimental effect on the constituents of body. Furthermore, dehydration causes negative mood state and hormonal changes by increasing the production of stress hormones (cortisol, prolactin) and sex hormones (testosterone).6,8–12 The term “stress” stands for any event that increases cortisol secretion.13 Cortisol is a catabolic hormone secreted from adrenal cortex and has effect on organic metabolism, that is, mobilizing nutrients. It preserves glucose resources by reducing glucose consumption and increasing cortisol hormones. Protein and fat metabolisms are also affected by cortisol levels. While increasing protein catabolism, cortisol decreases protein synthesis. Lipolysis is increased due to energy resources shifted to lipids. Cortisol secretion velocity changes due to stress, for example, prolactin increases, whereas sex steroids decrease.13–15 Having increased with glucocorticoid due to stress, prolactin insures functioning and survival of T lymphocytes. Prolactin inhibits glucocorticoids associated with stress response and may extend the endurance of immunity against stress.16 Decreased testosterone, unlike prolactin, is affected by cortisol secretion. Testosterone is the most important sex hormone among the male sex hormones, androgens. Along with the many physiologic functions in human body, testosterone is a crucial anabolic hormone. It stimulates functional sperm production, gland growth of the reproductive system, development of male secondary sex character and growth. Testosterone also stimulates protein synthesis and muscle growth.13–15 In relation with exercise, testosterone plays an important role in repairing bone, red blood cells, skeleton and muscle. During a certain amount of intense exercise, testosterone increases—as in cortisol—in parallel to the exercise when it is at its peak. After exercises, testosterone level decreases, whereas cortisol level increases due to decreased testosterone.15,17,18 It is reported that dietary restrictions and weight loss in a short time lead to negative effects on metabolism and endocrine parameters among the athletes, which disturbs the physiology and psychology leading to reduced performances. Meanwhile, these studies, in which changes seen in stress and testosterone hormones due to exercises are also examined, indicate that there is a negative correlation between stress hormones and testosterone hormones.2,6,18–21 In wrestling—one
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of these sports with weight classes—wrestlers often change their weight classes. These athletes obliged to participate in the competitions undergo fast weight losses in a short time through inappropriate methods. Quick weight losing in a short time results in dehydration among the wrestlers, and dehydration is thought to cause physical, physiological, psychological and hormonal changes. Yet, in the literature, the number of the biochemical studies on stress and testosterone levels of elite wrestlers is very limited. In this regard, the hypothesis is that dehydration may lead to an increase in cortisol and prolactin levels while decreasing testosterone levels among the wrestlers. The aim of this study was to determine weight loss and hydration levels based on blood osmolality level of the elite wrestlers before the competitions and to identify the correlation between hydration status, and stress (cortisol and prolactin) and testosterone.
MATERIALS AND METHODS Recruitment of the Subjects The sample of the study was composed of 68 elite male wrestlers who participated in international wrestling tournaments in the last 5 years and competed in the Turkish interuniversity wrestling championship (a 5-day tournament) in 2014. Of the 68 elite wrestlers, 12 did not want to give blood samples and declined to participate in the study. The study continued with 56 elite wrestlers. The ages of the athletes ranged from 18 to 22 years; the average age was 22.30 6 2.43 years; average height was 174.50 6 6.40 cm; average weight was 78.93 6 14.41 kg. For the study, medical ethics approval of Clinical Research Ethics Committee of Antalya Training and Research Hospital was obtained with the decision dated and numbered 06.10.2014 and 49/8-2014-213 in accordance with the guidelines of the revised Declaration of Helsinki. The sample was recruited using random sampling method and informed consents of the athletes were gained with voluntary participation. The participant athletes were asked not to use any kinds of medicine and ergogenic aids within 48 hours before competition-weighing to ensure standardization of the participant athletes. Those having used medicine and ergogenic aids were not included in the study. All participants were healthy, and no diseases that affected the blood values were seen during the study period. Biochemical Measurements and Analysis At the time of competition-weighing (a day before the competition, between 18.00–18.30), blood samples of 5 mL were taken from forearm veins of the participant athletes into 8.5-mL tubes with pure gel by specialists with closed vacutainer blood collection system and were immediately submitted to the laboratory where further analysis was performed. Blood samples were obtained from venous blood and then mixed with EDTA. Plasma was prepared by centrifugation at 4,000 rpm (Nuve NF-400, Ankara,Turkey) for 5 minutes at room temperature and then stored at 220°C before analysis. Biochemical analyses were achieved using Beckman Coulter AU2700 Plus biochemical auto-analyzer with Beckman Coulter kits. Hormone analyses were determined by Roche Hitachi Cobas e601 auto-analyzer with Roche kits. Experiment Protocol A personal information form was used to know the amount of body weight lost before the competition, how long it took to lose weight and how weight loss was achieved. The
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elite wrestlers reported to have lost body weights through sauna, intense exercise and food and fluid restrictions 1 to 5 days before the competition. Hydration levels and dehydration levels of the elite wrestlers were determined according to levels of plasma osmolarity in blood. Those with a plasma osmolarity of ,290 mOsm/L were considered to have normal daily body water content (euhydration), whereas those with a plasma osmolarity of .290 mOsm/L were considered to be dehydrated.22,23 Dehydration was established using the formula below: Pathologic Plasma Osmolarity 5 ð2 3 NAÞ þ ðBUN=2:8Þ þ ðGlucose=18Þ:24 Statistical Analyses The data were assessed with the SPSS program. For the assessment of the data, descriptive statistics were mainly used. Independent 2 samples were assessed using independent Samples t test, one of the parametric tests. Correlation status among the variables was evaluated with Spearman’s correlation coefficients. The accepted level of significance for all analyses was P , 0.05 with 95% confidence interval.
RESULTS It was found that 60.7% of the elite wrestlers underwent a short term high level of weight loss (1–5 days) before the competitions (3.77 6 1.85 kg). It was noted that athletes having undergone weight losses had a plasma osmolarity level above the reference range (296.63 6 4.30) and suffered from dehydration (Table 1). It was seen that there were significant differences between the athletes dehydrated and those nondehydrated in terms of Na+ values. Wrestlers dehydrated had considerably high level of Na+ as compared with those nondehydrated and came close to upper limit of the reference range (Table 1). It was discovered that there was a significant difference between the dehydrated and not dehydrated athletes in terms of cortisol and total testosterone levels (P , 0.001). When the differences were analyzed, dehydrated wrestlers had a higher level of cortisol than those who maintained euhydration but their total testosterone levels were lower (Table 1). It was detected that an association was present between plasma osmolarity (hydration levels), and cortisol (r 5 0.667) and total testosterone levels (r 5 20.627) among the elite wrestlers (P , 0.001). In other words, it was found that as plasma osmolarity increased so did cortisol, but not total testosterone. However, it was also seen that there was a correlation between cortisol and total testosterone (r 5 20.537). When the correlation status was studied, it was detected that as cortisol increased, total testosterone decreased (Figures 1–3).
DISCUSSION Several factors in sports affect performance of individuals. Methods used for athletic talent selection, basic biomotor abilities, technical-tactical-training methods, sportive nutrition and sportive health are just a few of these. No doubt that the most important factor is the sportive health. Frequently changed rules in such combat sports, such as judo, taekwondo, karate and wrestling, and weight classes make adaptation of the athletes problematic and unbearable in some instances. Athletes lose weight in a short time and as quickly as possible before a competition so that they can adapt themselves to frequently changing weight classes and compete against rivals who are less strong than them to gain advantage. Losing weight quickly and Volume 350, Number 2, August 2015
Associations Among Dehydration, Testosterone and Stress
TABLE 1. Comparison of the variables in terms of hydration levels Variables N POsm (mOsm/L) Body weight loss (kg) Percentage of body weight loss (%) POsm (mOsm/L) Na+ (mmol/L) BUN (mg/dL) Glucose (mg/dL) Cortisol (mg/dL) Prolactin (ng/mL) Total testosterone (ng/dL)
34 22 34 22 34 22 34 22 34 22 34 22 34 22 34 22 34 22
.290 #290 .290 #290 .290 #290 .290 #290 .290 #290 .290 #290 .290 #290 .290 #290 .290 #290
6 SD X
3.77 0.77 3.07 0.58 296.63 286.07 142.70 137.72 16.13 15.03 98.23 94.50 15.33 9.16 11.78 10.96 400.06 622.59
6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6
1.85 0.76 1.73 0.61 430 4.98 1.83 2.62 3.58 3.91 14.77 13.31 6.00 3.12 5.37 4.027 172.82 113.38
Reference range
t
P
—
7.209
0.001a
—
6.469
0.001a
—
8.420
0.001a
136–146
8.366
0.001a
8–20
1.077
0.286
74–106
0.960
0.341
2.3–11.9
4.435
0.001a
4.04–15.2
0.606
0.547
218–906
25.333
0.001a
a P , 0.001. BUN, blood urea nitrogen.
in a short time through inappropriate methods causes dehydration by affecting their hydration levels. Fluid loss in the body occurring due to dehydration leads to such problems as decreased total plasma volume, increased inner temperature of body (rectal temperature) and heartbeat, decreased heart minute volume, decreased total body fluid volume and muscle mass, weakness of muscle strength and decreased endurance.23,25,26 Even minimal changes in fluid volume of body (1%–2%) may damage endurance performance. In
addition to the lost fluid volume, plasma is lost too which decreases blood pressure and reduces blood flow into muscles and skin. These physiological cycles may lead to decreased performance. Besides, performance decreases will be more evident together with the extreme environmental conditions such as excessive outside temperature. It is emphasized that dehydration that occurs in low outside temperature and cooler environmental conditions can be tolerated more easily than dehydration that occurs in hotter environmental conditions
FIGURE 1. Correlation between total testosterone and plasma osmolarity (hydration). An association between plasma osmolarity (hydration levels) and total testosterone levels (r 5 20.627) among the elite wrestlers (P , 0.001) was observed.
Copyright © 2015 by the Southern Society for Clinical Investigation.
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FIGURE 2. Correlation between cortisol and plasma osmolarity (hydration). An association between plasma osmolarity (hydration levels) and cortisol levels (r 5 0.667) among the elite wrestlers (P , 0.001) was observed.
and thus may lead to fewer negative effects on performance.25,27,28 Furthermore, it is argued that low carbohydrate intake in addition to fluid and food restriction, utilization of energy combinations by the metabolism from fat and proteins, high level of plasma-free fatty acids and glucose inhibition occurring afterward may be other possible explanations of decreased performance.6,29,30 All of these results obtained from the studies suggest that weight losses caused by energy combination restrictions before the competitions in a short time may affect metabolism and endocrine parameters and may lead to
poor athletic performance and physical, physiological and psychological health disturbances. Scientific reports suggest that hydration can be predicted through urine-specific weight and through the plasma osmolarity level in blood and plasma osmolarity value should vary between 280 and 290 mOsm/L reference ranges. When the plasma osmolarity value is #290, hydration is considered normal (euhydration) but if it is .290, hydration is higher than the normal level (dehydration).22,23 In this study, hydration status of the elite wrestlers was assessed through the plasma osmolarity
FIGURE 3. Correlation between cortisol and total testosterone. An association between cortisol levels and total testosterone levels (r 5 20.537) among the elite wrestlers (P , 0.001) was observed.
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Associations Among Dehydration, Testosterone and Stress
value and it was seen that 60.7% of the wrestlers were subjected to dehydration due to weight loss before the competition. These results were in agreement with the hydration results of elite wrestlers obtained through urine-specific weight in the literature.1,2,7,31 Athletes reported that they lost body weight using nutrition and fluid restriction together with intense exercise (1– 5 days) before they were weighed in before the competition. These results indicated that athletes performed high level of weight loss in a short period before the competition, which resulted in acute dehydration. Acute dehydration affected their Na+ rates. Indeed; as far as the results of this study were concerned, it was noted that there were significant differences between the athletes dehydrated and those nondehydrated in terms of Na+ rates. It was identified that Na+ rates of the athletes dehydrated were considerably higher than those nondehydrated and came close to the upper limit of the reference range (Table 1). That athletes have Na+ rates above the reference range (.135 to ,145) in plasma causes hypernatremia. If Na+ concentration in blood samples of the people is #135, it is defined as hyponatremia, whereas if Na+ concentration in blood samples of the people is .145, it is defined as hypernatremia.32 Because of the dehydration associated with exercises, increased Na+ excreted through sweating causes hyponatremia. It was detected that cortisol and total testosterone levels of the elite wrestlers differed significantly in terms of hydration levels (P , 0.001). When the differences were examined, dehydrated wrestlers had higher level of cortisol but lower level of testosterone than those who maintained euhydration. It was found out that a correlation existed between plasma osmolarity (hydration level), and cortisol (r 5 0.667) and total testosterone (r 5 20.627) levels of the elite wrestlers (P , 0.001). It followed that as plasma osmolarity increased so did cortisol, but total testosterone decreased. However, it was noted that there was also a correlation between cortisol and total testosterone (r 5 20.537). When the correlation status was studied, it was seen that total testosterone decreased as cortisol increased. Similar data were previously reported by Strauss et al, Roemmich et al, Anderson et al, Wilson and Morley, Degoutte et al and Benton.6,8–11,30 The study of Is¸ık et al12 pointed out that an association existed between elite wrestlers’ weight loss before the competition and their depression levels, and as the amount of weight losses increased so did depression levels. The study of Anderson et al33 reported that low carbohydrate intake was correlated with cortisol, and carbohydrate load decreased cortisol levels. Besides, it was suggested that weight loss caused by food and fluid restrictions resulted in increases in cortisol levels, anger, tension and bad performance.6,30,34 It was identified that dehydration caused hormonal changes, and dehydration and cortisol and total testosterone hormones were correlated with each other. In this correlation status unlike increased cortisol levels due to dehydration, it was observed that total testosterone decreased, which may be interpreted that dehydration increased cortisol but not testosterone or that testosterone decreased due to cortisol. When previous studies were examined, it was seen that there were reports that supported both possibilities above mentioned.6,8,9,18,19,21,35–37 In this regard, some of the studies in the literature reported that dietary and fluid restrictions resulted in decreases in total testosterone levels and there was an important correlation between testosterone values and weight losses, body fat percentage and body fat losses.6,8,9 It may be argued that another reason for the decrease in total testosterone levels is the increase in cortisol levels, which could be explained with the fact that cortisol showed a negative correlation with total testosterone as demonstrated by the previous studies and this Copyright © 2015 by the Southern Society for Clinical Investigation.
study.18,19,35,36 Also, some studies emphasized that cortisol reduced and suppressed total testosterone in circulation.19,38 In general, intense exercise programs in combination with fluid and food restriction increased the cortisol levels of the wrestlers while decreasing testosterone levels. Thanks to increasing exercise, levels of cortisol and testosterone will end up increased cortisol levels but in the ongoing process, level of testosterone will start to decrease. It is possible that decreased testosterone may arise from dehydration caused by food and fluid restrictions or cortisol may suppress total testosterone and result in decreased testosterone. It was pointed out that there was a positive correlation between total testosterone and performance, and athletes with explosive strength and sprint performances had higher levels of testosterone.39–41 Moreover, anger, fatigue, tension and bad mood caused by fast weight loss were negatively correlated with performance34 and food and fluid restrictions that led to weight loss affected athletes’ psychology and physiology negatively before the competitions.6 The fact that weight loss of the elite athletes is achieved in a short time period through food and fluid restrictive methods not only reduces body components but also body fat percentage, bone density and fat-free mass. This negative outcome will reduce muscle strength, too. Thus, together with the increased cortisol and decreased testosterone due to short-term weight loss, changes seen in body components and losses due to food and fluid restriction will affect athletic performances negatively.
CONCLUSIONS As a result, it was discovered that wrestlers achieved quick and high level of weight loss before competitions in a very short time (1–5 days). It was seen that their hydration levels differed due to the weight loss, which was identified to be causing acute dehydration among the wrestlers. It was found that a correlation existed between hydration levels, and cortisol and testosterone levels of the wrestlers. The results of the study, which was an observational study, were important in that it demonstrated the current situation of the elite wrestlers. However, it would be important to discuss weight losses, changing hydration levels and the relation between stress and total testosterone of the wrestlers before and after the competitions through experimental approaches (pretest/posttest). ACKNOWLEDGMENTS The author thanks the Biochemical Specialist of Provoncial Hospital of Afyon, Dr. Ramazan Akbay, for his assessments and contributions in the biochemical analyses. The author also thanks Sefa Demir and Emel Kaya who are working as nurses in the Afyon Kocatepe University hospital for their technical assistance in taking the blood samples. REFERENCES 1. Artioli GG, Franchini E, Nicastro H, et al. The need of a weight management control program in judo: a proposal based on the successful case of wrestling. J Int Soc Sports Nutr 2010;7:15. 2. Coufalova K, Prokesova E, Maly T, et al. Body weight reduction in combat sports. Arcives of Budo 2013;4:267–72. 3. Utter AC. The new National Collegiate Athletic Association wrestling weight certification program and sport-seasonal changes in body composition of college wrestlers. J Strength Cond Res 2001;3:296–301. 4. Gibs AE, Pickerman J, Sekiya JK. Weight management in amateur wrestling. Sports Health 2009;1:227–30.
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5. Choma CW, Sforzo GA, Keller BA. Impact of rapid weight loss on cognitive function in collegiate wrestlers. Med Sci Sports Exerc 1998; 30:746–9.
25. Demirkan E, Koz M, Kutlu M. The effects of dehydration on athletic performance and monitoring hydration levels. J Spormetre 2010;3: 81–92.
6. Degoutte F, Jouanel P, Begue RJ, et al. Food restriction, performance, biochemical, psychological, and endocrine changes in judo athletes. Int J Sports Med 2006;27:9–18.
26. Proteau S, Pelle A, Collomp K. Bone density in elite judoists and effects of weight cycling on bone metabolic balance. Med Sci Sports Exerc 2006;38:694–700.
7. Demirkan E, Kutlu M, Koz M, et al. The investigation of body composition and hydration changes in elite wrestlers. Selçuk Univ J Phys Edu Sports Sci 2012;14:179–83.
27. Wilmore JH, Costill DL. Physiology of Sport and Exercise, 3rd ed. Champaign (IL): Human Kinetics; 2004.
8. Strauss RH, Lanese RR, Malarkey WB. Weight loss in amateur wrestlers and its effect on serum testosterone levels. JAMA 1985;20:3337–8. 9. Roemmich JN, Sinning WE. Weight loss and wrestling training: effects on growth-related hormones. J Appl Physiol (1985) 1997;82: 1760–4. 10. Wilson MM, Morley JE. Impaired cognitive function and mental performance in mild dehydration. Eur J Clin Nutr 2003;57:24–9.
28. Shirreffs SM. The importance of good hydration for work and exercise performance. Nutr Rev 2005;63:14–21. 29. Bisschop PH, Pereira Arias AM, Ackermans MT, et al. The effects of carbohydrate variation in isocaloric diets on glycogenolysis and gluconeogenesis in healthy men. J Clin Endocrinol Metab 2000;85: 1963–7.
11. Benton D. Dehydration influences mood and cognition: a plausible hypothesis? Nutrients 2011;3:557–73.
30. Anderson DA, Shapiro JR, Lundgren JD, et al. Self-reported dietary restraint is associated with elevated levels of salivary cortisol. Appetite 2002;38:13–17.
12. Is¸ik Ö, Gökdemir K, Bastik C, et al. Study on elite wrestlers: weight loss and depression. Nigde Univ J Phys Edu Sport Sci 2013;7:216–23.
31. Lambert C, Jones B. Alternatives to rapid weight loss in us wrestling. Int J Sports Med 2010;31:523–528.
13. Widmaier EP, Raff H, Strang KT. Vander’s human physiology: the mechanisms of body function. McGraw-Hill Higher Education, 2011.
32. Eijsvogels TM, Scholten RR, Duijnhoven NTL, et al. Sex difference in fluid balance responses during prolonged exercise. Scand J Med Sci Sports 2013;2:198–206.
14. Aktümsek A. Anatomy and physiology. Human biology, 2nd ed. Ankara, Turkey: Nobel Publication; 2004. p. 186–90. _ Sports physiology and performance 15. Günay M, Tamer K, Cicioglu I. measurement, 1st ed. Ankara, Turkey: Gazi Bookstore; 2006. p. 246–63. 16. Türsen Ü. Stress, hormones and skin. Dermatoz 2011;2:308–19. 17. Zitzmann M, Nieschlag E. Testosterone levels in healthy men in relation to behavioral and physical characteristics: facts and constructs. Eur J Endocrinol 2001;144:183–97. 18. Brownlee KK, Moore AW, Hackney AC. Relationship between circulating cortisol and testosterone: influence of physical exercise. J Sports Sci Med 2005;4:76–83. 19. Daly W, Seegers CA, Rubin D, et al. Relationship between stress hormones and testosterone with prolonged endurance exercise. Eur J Appl Physiol 2005;93:375–80. 20. Zümrütdal A. Basic principles in liquid electrolyte treatment [in Turkish]. Anatol J Cardiol 2013;13:171–7. 21. Judelson DA, Maresh CM, Yamamoto LM, et al. Effect of hydration state on resistance exercise-induced endocrine markers of anabolism, catabolism, and metabolism. J Appl Physiol (1985) 2008;105:816–24. 22. Popowski LA, Oppliger RA, Patrick LG, et al. Blood and urinary measures of hydration status during progressive acute dehydration. Med Sci Sports Exerc 2001;33:747–53. 23. Cheuvront SN, Ely BR, Kenefick RW, et al. Biological variation and diagnostic accuracy of dehydration assessment markers. Am J Clin Nutr 2010;92:565–73. 24. García-Morales EJ, Cariappa R, Parvin CA, et al. Osmole gap in neurologic-neurosurgical intensive care unit: its normal value, calculation, and relationship with mannitol serum concentrations. Crit Care Med 2004;32:986–91.
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33. Anderson RA, Bryden NA, Polansky MM, et al. Effects of carbohydrate loading and underwater exercise on circulating cortisol, insülin and urinary losses of hromium and zinc. Eur J Appl Physiol Occup Physiol 1991;63:146–150. 34. Hall CJ, Lane AM. Effects of rapid weight loss on mood and performance among amateur boxers. Br J Sports Med 2001;35:390–5. 35. Cumming DC, Quigley ME, Yen SSC. Acute suppression of circulating testosterone levels by cortisol in men. J Clin Endocrinol Metab 1983;57:671–3. 36. Hackney AC, Sharp RL, Runyan WS, et al. Relationship of resting prolactin and testosterone in males during intensive training. Br J Sports Med 1989;23:194. 37. Maresh CM, Whittlesey MJ, Armstrong LE, et al. Effect of hydration state on testosterone and cortisol responses to training-intensity exercise in collegiate runners. Int J Sports Med 2006;27:765–70. 38. Hackney AC, Dobridge J. Exercise and male hypogonadism: testosterone, the hypothalamic-pituitary-testicular axis, and physical exercise. In: Winters S, editor. Male Hypogonadism: Basic, Clinical, and Therapeutic Principles. Totowa (NJ): Humana Press; 2003. p. 305–30. 39. Cardinale M, Stone MH. Is testosterone influencing explosive performance? J Strength Cond Res 2006;20:103–7. 40. Crewther BT, Christian C. Relationships between salivary testosterone and cortisol concentrations and training performance in Olympic weightlifters. J Sports Med Phys Fitness 2010;50:371–5. 41. Bosco C, Tihanyit J, Viru A. Relationships between field fitness test and basal serum testosterone and cortisol levels in soccer players. Clin Physiol 2008;16:317–22.
Volume 350, Number 2, August 2015
Associations Among Dehydration, Testosterone and Stress Hormones in Terms of Body Weight Loss Before Competition _ Yıldırım Irfan, PhD
Abstract: Background: In weight class sports, such as judo, taekwondo and wrestling, reducing body weight before competitions is common. However, it is recommended that weight loss per week should not exceed 1.5% of total body weight otherwise, athletes’ metabolism and endocrine parameters are negatively affected, which will deteriorate their physiology and psychology and thus decrease their performance. The aim of this study was to determine weight loss and hydration levels after weight loss before competitions among the elite wrestlers and to explore the association between hydration levels, and stress and testosterone. Methods: This was an observational study. The study was undertaken with 56 voluntary athletes who participated in wrestling championship. With blood samples taken from the wrestlers, glucose, blood urea nitrogen, sodium (Na), cortisol, prolactin and testosterone hormone analyses were evaluated by a specialist at a biochemical laboratory. Results: It was found out that according to plasma osmolarity levels, there were significant differences between those dehydrated and those who maintained euhydration in terms of cortisol and total testosterone levels (P , 0.001). It was detected that an association was present between plasma osmolarity, and cortisol (r 5 0.667) and total testosterone levels (r 5 20.627) among the elite wrestlers. Conclusions: It was discovered that elite wrestlers were subjected to quick and high level of weight losses before competitions in a very short time (1–5 days). It was seen that their hydration levels differed due to the weight loss, which was explored to be causing acute dehydration among the wrestlers. Key Indexing Terms: Body Weight Loss; Stress; Cortisol; Total Testosterone; Dehydration. [Am J Med Sci 2015;350(2):103–108.]
I
n combat sports, athletes are classified according to their body weights and grouped into competition weights. Weight classes in wrestling, which is one of those combat sports, are 55, 60, 66, 74, 84, 96 and 120 kg. It is obligatory that wrestlers should have a body weight appropriate for the weight classes in which they are going to compete when they are weighed in on the day (between 18.00 and 18.30) before the competition. However, many athletes want to compete in lower weight classes by reducing body mass index due to the idea of competing against opponents who are less strong than them, which is, they think, advantageous. Therefore, reducing body weight before competitions is a commonly used method in weight class sports, such as judo, taekwondo, karate and wrestling. Athletes lose body weight using such inappropriate methods as intense exercises, sauna, nutrition and fluid restriction in a very short time (1–7 days) before the competitions.1–4 In NCAA (Wrestling Weight Certification) it is reported that weight loss per week From the School of Physical Education and Sports, Afyon Kocatepe University, Afyonkarahisar, Turkey. Submitted February 14, 2015; accepted in revised form May 12, 2015. The author has no financial or other conflicts of interest to disclose. This study was presented 4th International Conference on Science Culture and Sport, 22–26 May 2015, Ohrid-Macedonia. _ Correspondence: Irfan Yıldırım, PhD, School of Physical Education and Sports, Afyon Kocatepe University, Afyonkarahisar, Turkey (E-mail: [email protected]).
The American Journal of the Medical Sciences
should not exceed 1.5% of total body weight.3 Otherwise, a short term high level of weight loss will lead to dehydration, which will result in deteriorations in the athletes’ physiology and psychology by causing negative effects on their metabolisms and endocrine parameters and thus their performance will decrease.1–4 Dehydration causes a decrease in plasma volume of the organism, acute cardiovascular disorders (arrhythmia, hypotension, tachycardia), breakdown of thermoregulation, decreased activity of immune system, insufficient distribution of nutrition/ energy resources and slowdown of metabolic wastes in athletes and, as a result, adversely affects their health and performance.2,5–7 Because weight losses generally occur in a shorter time, thanks to some methods in combination with nutrition and fluid restrictions; these losses also have detrimental effect on the constituents of body. Furthermore, dehydration causes negative mood state and hormonal changes by increasing the production of stress hormones (cortisol, prolactin) and sex hormones (testosterone).6,8–12 The term “stress” stands for any event that increases cortisol secretion.13 Cortisol is a catabolic hormone secreted from adrenal cortex and has effect on organic metabolism, that is, mobilizing nutrients. It preserves glucose resources by reducing glucose consumption and increasing cortisol hormones. Protein and fat metabolisms are also affected by cortisol levels. While increasing protein catabolism, cortisol decreases protein synthesis. Lipolysis is increased due to energy resources shifted to lipids. Cortisol secretion velocity changes due to stress, for example, prolactin increases, whereas sex steroids decrease.13–15 Having increased with glucocorticoid due to stress, prolactin insures functioning and survival of T lymphocytes. Prolactin inhibits glucocorticoids associated with stress response and may extend the endurance of immunity against stress.16 Decreased testosterone, unlike prolactin, is affected by cortisol secretion. Testosterone is the most important sex hormone among the male sex hormones, androgens. Along with the many physiologic functions in human body, testosterone is a crucial anabolic hormone. It stimulates functional sperm production, gland growth of the reproductive system, development of male secondary sex character and growth. Testosterone also stimulates protein synthesis and muscle growth.13–15 In relation with exercise, testosterone plays an important role in repairing bone, red blood cells, skeleton and muscle. During a certain amount of intense exercise, testosterone increases—as in cortisol—in parallel to the exercise when it is at its peak. After exercises, testosterone level decreases, whereas cortisol level increases due to decreased testosterone.15,17,18 It is reported that dietary restrictions and weight loss in a short time lead to negative effects on metabolism and endocrine parameters among the athletes, which disturbs the physiology and psychology leading to reduced performances. Meanwhile, these studies, in which changes seen in stress and testosterone hormones due to exercises are also examined, indicate that there is a negative correlation between stress hormones and testosterone hormones.2,6,18–21 In wrestling—one
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of these sports with weight classes—wrestlers often change their weight classes. These athletes obliged to participate in the competitions undergo fast weight losses in a short time through inappropriate methods. Quick weight losing in a short time results in dehydration among the wrestlers, and dehydration is thought to cause physical, physiological, psychological and hormonal changes. Yet, in the literature, the number of the biochemical studies on stress and testosterone levels of elite wrestlers is very limited. In this regard, the hypothesis is that dehydration may lead to an increase in cortisol and prolactin levels while decreasing testosterone levels among the wrestlers. The aim of this study was to determine weight loss and hydration levels based on blood osmolality level of the elite wrestlers before the competitions and to identify the correlation between hydration status, and stress (cortisol and prolactin) and testosterone.
MATERIALS AND METHODS Recruitment of the Subjects The sample of the study was composed of 68 elite male wrestlers who participated in international wrestling tournaments in the last 5 years and competed in the Turkish interuniversity wrestling championship (a 5-day tournament) in 2014. Of the 68 elite wrestlers, 12 did not want to give blood samples and declined to participate in the study. The study continued with 56 elite wrestlers. The ages of the athletes ranged from 18 to 22 years; the average age was 22.30 6 2.43 years; average height was 174.50 6 6.40 cm; average weight was 78.93 6 14.41 kg. For the study, medical ethics approval of Clinical Research Ethics Committee of Antalya Training and Research Hospital was obtained with the decision dated and numbered 06.10.2014 and 49/8-2014-213 in accordance with the guidelines of the revised Declaration of Helsinki. The sample was recruited using random sampling method and informed consents of the athletes were gained with voluntary participation. The participant athletes were asked not to use any kinds of medicine and ergogenic aids within 48 hours before competition-weighing to ensure standardization of the participant athletes. Those having used medicine and ergogenic aids were not included in the study. All participants were healthy, and no diseases that affected the blood values were seen during the study period. Biochemical Measurements and Analysis At the time of competition-weighing (a day before the competition, between 18.00–18.30), blood samples of 5 mL were taken from forearm veins of the participant athletes into 8.5-mL tubes with pure gel by specialists with closed vacutainer blood collection system and were immediately submitted to the laboratory where further analysis was performed. Blood samples were obtained from venous blood and then mixed with EDTA. Plasma was prepared by centrifugation at 4,000 rpm (Nuve NF-400, Ankara,Turkey) for 5 minutes at room temperature and then stored at 220°C before analysis. Biochemical analyses were achieved using Beckman Coulter AU2700 Plus biochemical auto-analyzer with Beckman Coulter kits. Hormone analyses were determined by Roche Hitachi Cobas e601 auto-analyzer with Roche kits. Experiment Protocol A personal information form was used to know the amount of body weight lost before the competition, how long it took to lose weight and how weight loss was achieved. The
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elite wrestlers reported to have lost body weights through sauna, intense exercise and food and fluid restrictions 1 to 5 days before the competition. Hydration levels and dehydration levels of the elite wrestlers were determined according to levels of plasma osmolarity in blood. Those with a plasma osmolarity of ,290 mOsm/L were considered to have normal daily body water content (euhydration), whereas those with a plasma osmolarity of .290 mOsm/L were considered to be dehydrated.22,23 Dehydration was established using the formula below: Pathologic Plasma Osmolarity 5 ð2 3 NAÞ þ ðBUN=2:8Þ þ ðGlucose=18Þ:24 Statistical Analyses The data were assessed with the SPSS program. For the assessment of the data, descriptive statistics were mainly used. Independent 2 samples were assessed using independent Samples t test, one of the parametric tests. Correlation status among the variables was evaluated with Spearman’s correlation coefficients. The accepted level of significance for all analyses was P , 0.05 with 95% confidence interval.
RESULTS It was found that 60.7% of the elite wrestlers underwent a short term high level of weight loss (1–5 days) before the competitions (3.77 6 1.85 kg). It was noted that athletes having undergone weight losses had a plasma osmolarity level above the reference range (296.63 6 4.30) and suffered from dehydration (Table 1). It was seen that there were significant differences between the athletes dehydrated and those nondehydrated in terms of Na+ values. Wrestlers dehydrated had considerably high level of Na+ as compared with those nondehydrated and came close to upper limit of the reference range (Table 1). It was discovered that there was a significant difference between the dehydrated and not dehydrated athletes in terms of cortisol and total testosterone levels (P , 0.001). When the differences were analyzed, dehydrated wrestlers had a higher level of cortisol than those who maintained euhydration but their total testosterone levels were lower (Table 1). It was detected that an association was present between plasma osmolarity (hydration levels), and cortisol (r 5 0.667) and total testosterone levels (r 5 20.627) among the elite wrestlers (P , 0.001). In other words, it was found that as plasma osmolarity increased so did cortisol, but not total testosterone. However, it was also seen that there was a correlation between cortisol and total testosterone (r 5 20.537). When the correlation status was studied, it was detected that as cortisol increased, total testosterone decreased (Figures 1–3).
DISCUSSION Several factors in sports affect performance of individuals. Methods used for athletic talent selection, basic biomotor abilities, technical-tactical-training methods, sportive nutrition and sportive health are just a few of these. No doubt that the most important factor is the sportive health. Frequently changed rules in such combat sports, such as judo, taekwondo, karate and wrestling, and weight classes make adaptation of the athletes problematic and unbearable in some instances. Athletes lose weight in a short time and as quickly as possible before a competition so that they can adapt themselves to frequently changing weight classes and compete against rivals who are less strong than them to gain advantage. Losing weight quickly and Volume 350, Number 2, August 2015
Associations Among Dehydration, Testosterone and Stress
TABLE 1. Comparison of the variables in terms of hydration levels Variables N POsm (mOsm/L) Body weight loss (kg) Percentage of body weight loss (%) POsm (mOsm/L) Na+ (mmol/L) BUN (mg/dL) Glucose (mg/dL) Cortisol (mg/dL) Prolactin (ng/mL) Total testosterone (ng/dL)
34 22 34 22 34 22 34 22 34 22 34 22 34 22 34 22 34 22
.290 #290 .290 #290 .290 #290 .290 #290 .290 #290 .290 #290 .290 #290 .290 #290 .290 #290
6 SD X
3.77 0.77 3.07 0.58 296.63 286.07 142.70 137.72 16.13 15.03 98.23 94.50 15.33 9.16 11.78 10.96 400.06 622.59
6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6
1.85 0.76 1.73 0.61 430 4.98 1.83 2.62 3.58 3.91 14.77 13.31 6.00 3.12 5.37 4.027 172.82 113.38
Reference range
t
P
—
7.209
0.001a
—
6.469
0.001a
—
8.420
0.001a
136–146
8.366
0.001a
8–20
1.077
0.286
74–106
0.960
0.341
2.3–11.9
4.435
0.001a
4.04–15.2
0.606
0.547
218–906
25.333
0.001a
a P , 0.001. BUN, blood urea nitrogen.
in a short time through inappropriate methods causes dehydration by affecting their hydration levels. Fluid loss in the body occurring due to dehydration leads to such problems as decreased total plasma volume, increased inner temperature of body (rectal temperature) and heartbeat, decreased heart minute volume, decreased total body fluid volume and muscle mass, weakness of muscle strength and decreased endurance.23,25,26 Even minimal changes in fluid volume of body (1%–2%) may damage endurance performance. In
addition to the lost fluid volume, plasma is lost too which decreases blood pressure and reduces blood flow into muscles and skin. These physiological cycles may lead to decreased performance. Besides, performance decreases will be more evident together with the extreme environmental conditions such as excessive outside temperature. It is emphasized that dehydration that occurs in low outside temperature and cooler environmental conditions can be tolerated more easily than dehydration that occurs in hotter environmental conditions
FIGURE 1. Correlation between total testosterone and plasma osmolarity (hydration). An association between plasma osmolarity (hydration levels) and total testosterone levels (r 5 20.627) among the elite wrestlers (P , 0.001) was observed.
Copyright © 2015 by the Southern Society for Clinical Investigation.
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FIGURE 2. Correlation between cortisol and plasma osmolarity (hydration). An association between plasma osmolarity (hydration levels) and cortisol levels (r 5 0.667) among the elite wrestlers (P , 0.001) was observed.
and thus may lead to fewer negative effects on performance.25,27,28 Furthermore, it is argued that low carbohydrate intake in addition to fluid and food restriction, utilization of energy combinations by the metabolism from fat and proteins, high level of plasma-free fatty acids and glucose inhibition occurring afterward may be other possible explanations of decreased performance.6,29,30 All of these results obtained from the studies suggest that weight losses caused by energy combination restrictions before the competitions in a short time may affect metabolism and endocrine parameters and may lead to
poor athletic performance and physical, physiological and psychological health disturbances. Scientific reports suggest that hydration can be predicted through urine-specific weight and through the plasma osmolarity level in blood and plasma osmolarity value should vary between 280 and 290 mOsm/L reference ranges. When the plasma osmolarity value is #290, hydration is considered normal (euhydration) but if it is .290, hydration is higher than the normal level (dehydration).22,23 In this study, hydration status of the elite wrestlers was assessed through the plasma osmolarity
FIGURE 3. Correlation between cortisol and total testosterone. An association between cortisol levels and total testosterone levels (r 5 20.537) among the elite wrestlers (P , 0.001) was observed.
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value and it was seen that 60.7% of the wrestlers were subjected to dehydration due to weight loss before the competition. These results were in agreement with the hydration results of elite wrestlers obtained through urine-specific weight in the literature.1,2,7,31 Athletes reported that they lost body weight using nutrition and fluid restriction together with intense exercise (1– 5 days) before they were weighed in before the competition. These results indicated that athletes performed high level of weight loss in a short period before the competition, which resulted in acute dehydration. Acute dehydration affected their Na+ rates. Indeed; as far as the results of this study were concerned, it was noted that there were significant differences between the athletes dehydrated and those nondehydrated in terms of Na+ rates. It was identified that Na+ rates of the athletes dehydrated were considerably higher than those nondehydrated and came close to the upper limit of the reference range (Table 1). That athletes have Na+ rates above the reference range (.135 to ,145) in plasma causes hypernatremia. If Na+ concentration in blood samples of the people is #135, it is defined as hyponatremia, whereas if Na+ concentration in blood samples of the people is .145, it is defined as hypernatremia.32 Because of the dehydration associated with exercises, increased Na+ excreted through sweating causes hyponatremia. It was detected that cortisol and total testosterone levels of the elite wrestlers differed significantly in terms of hydration levels (P , 0.001). When the differences were examined, dehydrated wrestlers had higher level of cortisol but lower level of testosterone than those who maintained euhydration. It was found out that a correlation existed between plasma osmolarity (hydration level), and cortisol (r 5 0.667) and total testosterone (r 5 20.627) levels of the elite wrestlers (P , 0.001). It followed that as plasma osmolarity increased so did cortisol, but total testosterone decreased. However, it was noted that there was also a correlation between cortisol and total testosterone (r 5 20.537). When the correlation status was studied, it was seen that total testosterone decreased as cortisol increased. Similar data were previously reported by Strauss et al, Roemmich et al, Anderson et al, Wilson and Morley, Degoutte et al and Benton.6,8–11,30 The study of Is¸ık et al12 pointed out that an association existed between elite wrestlers’ weight loss before the competition and their depression levels, and as the amount of weight losses increased so did depression levels. The study of Anderson et al33 reported that low carbohydrate intake was correlated with cortisol, and carbohydrate load decreased cortisol levels. Besides, it was suggested that weight loss caused by food and fluid restrictions resulted in increases in cortisol levels, anger, tension and bad performance.6,30,34 It was identified that dehydration caused hormonal changes, and dehydration and cortisol and total testosterone hormones were correlated with each other. In this correlation status unlike increased cortisol levels due to dehydration, it was observed that total testosterone decreased, which may be interpreted that dehydration increased cortisol but not testosterone or that testosterone decreased due to cortisol. When previous studies were examined, it was seen that there were reports that supported both possibilities above mentioned.6,8,9,18,19,21,35–37 In this regard, some of the studies in the literature reported that dietary and fluid restrictions resulted in decreases in total testosterone levels and there was an important correlation between testosterone values and weight losses, body fat percentage and body fat losses.6,8,9 It may be argued that another reason for the decrease in total testosterone levels is the increase in cortisol levels, which could be explained with the fact that cortisol showed a negative correlation with total testosterone as demonstrated by the previous studies and this Copyright © 2015 by the Southern Society for Clinical Investigation.
study.18,19,35,36 Also, some studies emphasized that cortisol reduced and suppressed total testosterone in circulation.19,38 In general, intense exercise programs in combination with fluid and food restriction increased the cortisol levels of the wrestlers while decreasing testosterone levels. Thanks to increasing exercise, levels of cortisol and testosterone will end up increased cortisol levels but in the ongoing process, level of testosterone will start to decrease. It is possible that decreased testosterone may arise from dehydration caused by food and fluid restrictions or cortisol may suppress total testosterone and result in decreased testosterone. It was pointed out that there was a positive correlation between total testosterone and performance, and athletes with explosive strength and sprint performances had higher levels of testosterone.39–41 Moreover, anger, fatigue, tension and bad mood caused by fast weight loss were negatively correlated with performance34 and food and fluid restrictions that led to weight loss affected athletes’ psychology and physiology negatively before the competitions.6 The fact that weight loss of the elite athletes is achieved in a short time period through food and fluid restrictive methods not only reduces body components but also body fat percentage, bone density and fat-free mass. This negative outcome will reduce muscle strength, too. Thus, together with the increased cortisol and decreased testosterone due to short-term weight loss, changes seen in body components and losses due to food and fluid restriction will affect athletic performances negatively.
CONCLUSIONS As a result, it was discovered that wrestlers achieved quick and high level of weight loss before competitions in a very short time (1–5 days). It was seen that their hydration levels differed due to the weight loss, which was identified to be causing acute dehydration among the wrestlers. It was found that a correlation existed between hydration levels, and cortisol and testosterone levels of the wrestlers. The results of the study, which was an observational study, were important in that it demonstrated the current situation of the elite wrestlers. However, it would be important to discuss weight losses, changing hydration levels and the relation between stress and total testosterone of the wrestlers before and after the competitions through experimental approaches (pretest/posttest). ACKNOWLEDGMENTS The author thanks the Biochemical Specialist of Provoncial Hospital of Afyon, Dr. Ramazan Akbay, for his assessments and contributions in the biochemical analyses. The author also thanks Sefa Demir and Emel Kaya who are working as nurses in the Afyon Kocatepe University hospital for their technical assistance in taking the blood samples. REFERENCES 1. Artioli GG, Franchini E, Nicastro H, et al. The need of a weight management control program in judo: a proposal based on the successful case of wrestling. J Int Soc Sports Nutr 2010;7:15. 2. Coufalova K, Prokesova E, Maly T, et al. Body weight reduction in combat sports. Arcives of Budo 2013;4:267–72. 3. Utter AC. The new National Collegiate Athletic Association wrestling weight certification program and sport-seasonal changes in body composition of college wrestlers. J Strength Cond Res 2001;3:296–301. 4. Gibs AE, Pickerman J, Sekiya JK. Weight management in amateur wrestling. Sports Health 2009;1:227–30.
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5. Choma CW, Sforzo GA, Keller BA. Impact of rapid weight loss on cognitive function in collegiate wrestlers. Med Sci Sports Exerc 1998; 30:746–9.
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