Effect of intense training on plasma leptin in male and female swimmers.
ABSTRACT The purpose of this study was to determine whether fasting plasma leptin concentration was altered with an increase in training volume in competitive male and female athletes.
Intercollegiate male (N = 9) and female (N = 12) swimmers were examined during the preseason and at two times during the mid-season (mid-season 1 and mid-season 2) when training volume was relatively high (33,000 m.wk(-1)). Body composition (hydrostatic weighing), energy intake and expenditure, and fasting plasma leptin concentration were measured.
In the women, there was a significant (P < 0.05) decline in fat mass (2 kg) with the increase in training volume, which was not accompanied by a reduction in fasting leptin (12.8 +/- 1.5 vs 11.0 +/- 1.2 vs 11.0 +/- 1.5 ng.mL(-1) for preseason, mid-season 1, and mid-season 2, respectively). In the men, there were no significant changes in body composition, body mass, or fasting leptin (4.4 +/- 0.8 vs 4.3 +/- 0.8 vs 4.6 +/- 0.8 ng.mL(-1), respectively).
These findings suggest 1) plasma leptin is not sensitive to an increase in training volume and 2) leptin may not be indicative of changes in fat mass with an increase in training volume in female athletes. These data suggest that leptin may not be useful in monitoring relative training stress in athletes.
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ABSTRACT: The purpose of this study was to find the change and correlation between obesity factors and body composition according to regular exercise. Thirty-six sturdy men at twenty years old in 'K' university students were participated in this study. The subjects were randomly divided into two groups (n= 18 in each group): control group and regular exercise group. Exercise program composed of three programs: warm-up (10 min), work-out (30-60 min), cool-down (10 min), and categorized by five days per week for eight weeks. Aerobic exercise using a treadmill at 60% of heart rate reserve was performed, and weight training was composed of nine different exercises for the large muscles. Before the performing regular exercise, there was no significant difference between control and regular exercise groups. In the present results, 8 weeks regular exercise significantly decreased leptin, weight, fat mass, % fat, waist to hip ratio (WHR), and body mass index (BMI) more than compared to before performing regular exercise, whereas significantly enhanced lean mass more than compared to before performing regular exercise. Furthermore, regular exercise group reduced leptin, weight, fat mass, % fat, WHR, and BMI compared to control group in the post test. In the correlation of obesity-related factors and body composition, tumor necrosis factor-α (TNF-α) showed correlation with weight, lean mass, and fat mass after performing regular exercise. Here in this study, we suggest that regular exercise is a valuable tool for the improvement of health in the sturdy men, because regular exercise suppresses body fat and obesity-related factors.Journal of exercise rehabilitation. 04/2013; 9(2):256-262.
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ABSTRACT: Reçu le 5 février 2003 ; accepté le 10 mai 2003 Résumé Objectifs. – Examiner les effets de l'exercice physique sur les taux de leptine. Actualités. – La leptine, hormone adipocytaire joue un rôle clé dans la régulation de la balance énergétique. Elle agit comme agent de satiété en informant le système nerveux central sur l'état des stocks énergétiques et intervient sur la régulation du métabolisme lipidique. L'exercice, par les modifications métaboliques et hormonales et les changements de dépense énergétique qu'il implique, peut contribuer à la régulation des taux circulants de leptine et à celle de son action. Il existerait un seuil dans la dépense énergétique à atteindre à l'exercice aigu (~ 800 kcal) susceptible de diminuer les taux de leptine. Un entraînement de courte ou longue durée (< ou > 12 semaines) ne modifierait les taux basaux de leptine que s'il implique une modification de composition corporelle (diminution de la masse grasse). La restriction calorique s'imposerait donc à l'entraînement pour modifier les taux de leptine. Perspectives et projets. – Des mécanismes physiologiques sont proposés pour expliquer les modifications des taux de leptine à l'exercice. La baisse de l'insuline et l'augmentation des catécholamines à l'exercice pourraient être les médiateurs de la réponse leptine. Le suivi des modifications des taux de leptine à l'exercice physique pourrait être un bon indicateur de l'état nutritionnel, des modifications de composition corporelle et des éventuelles dérégulations des fonctions de reproduction et, s'avérerait intéressant dans le cadre du syndrome du surentraî-nement.Science & Sports 02/2004; 19(1). · 0.54 Impact Factor
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ABSTRACT: The plasma leptin concentration depends on many factors with a substantial role played by physical activity. The aim of this study was the evaluation of the effects of body fat and fat free mass as well circulating glucose and cortisol on plasma leptin concentrations in active men and women. A total of 26 physical education students (13 men and 13 women)-took part in the study. Their physical activity during the study was only thatrequired by theie study program. No one was engaged in high-performance sports. Fasting blood samples were taken from the antecubital vein into lithium heparin tubes and centrifuged to separate plasma specimens. Plasma leptin levels were determined using radioimmunoassay and commercial kits (Linco, USA). Cortisol was determined by means of ELISA method and IBL kits (Germany). Glucose was assayed by the oxidase method using Randox commercial kits (Randox Laboratories, Great Britain). Body fat was estimated using the BIA method (RJL System INC., USA). Despite the lack of difference in fat mass between sexes circulating leptin in women (6.5 ng·ml -1) was significantly higher than in men (2.4 ng·ml -1). Plasma leptin concentrations in both men and women were not correlated with circulating glucose and cortisol. Moreover, neither in men nor in women were they correlated with the percent of body fat. In contrast, in men plasma leptin levels were significantly correlated with fat mass expressed in kilograms (r=0.56; p<0.05). In women circulating leptin was significantly and inversely correlated with the ratio of fat-free mass to fat mass (r=-0.71; p<0.006). Our results indicate that the effect of body fat on plasma leptin concentrations differs in active men and women, probably due to pronounced fat-free mass effects on plasma hormone levels in women but not in men.