Leptin Production during Moderate-Intensity Aerobic Exercise 1 (original) (raw)
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Plasma leptin and exercise: recent findings
Sports medicine, 2001
stimulates lipid metabolism, and increases energy expenditure. These effects implicate leptin as a major regulator of energy homeostasis, which may serve to limit excess energy storage. As plasma leptin concentrations are tightly coupled with fat mass in humans, decreases in adipose mass with weight loss coincide with decreased concentrations of circulating leptin. However, due to many confounding factors, the effects of exercise on circulating leptin are less clear. The data from investigations examining single exercise bouts suggest that serum leptin concentrations are unaltered by short duration (41 minutes or less), non-exhaustive exercise, but may be affected by short duration, exhaustive exercise. More convincingly, studies investigating long duration exercise bouts indicate that serum leptin concentrations are reduced with exercise durations ranging from one to multiple hours. These findings raise speculation that exercise-associated reductions in leptin may be due to alterations in nutrient availability or nutrient flux at the level of the adipocytes, the primary site of leptin production and secretion. Thus, one purpose of this review is to discuss the effects of exercise on circulating leptin concentrations with special emphasis on studies that have examined single exercise bouts that are associated with high levels of energy expenditure and energy deficit. In addition, a 'nutrient sensing pathway' (the hexosamine biosynthetic pathway), which regulates leptin gene expression, will be discussed as a possible mechanism by which exercise-induced energy deficit may modulate serum leptin concentrations.
Sports Medicine, 2001
stimulates lipid metabolism, and increases energy expenditure. These effects implicate leptin as a major regulator of energy homeostasis, which may serve to limit excess energy storage. As plasma leptin concentrations are tightly coupled with fat mass in humans, decreases in adipose mass with weight loss coincide with decreased concentrations of circulating leptin. However, due to many confounding factors, the effects of exercise on circulating leptin are less clear. The data from investigations examining single exercise bouts suggest that serum leptin concentrations are unaltered by short duration (41 minutes or less), non-exhaustive exercise, but may be affected by short duration, exhaustive exercise. More convincingly, studies investigating long duration exercise bouts indicate that serum leptin concentrations are reduced with exercise durations ranging from one to multiple hours. These findings raise speculation that exercise-associated reductions in leptin may be due to alterations in nutrient availability or nutrient flux at the level of the adipocytes, the primary site of leptin production and secretion. Thus, one purpose of this review is to discuss the effects of exercise on circulating leptin concentrations with special emphasis on studies that have examined single exercise bouts that are associated with high levels of energy expenditure and energy deficit. In addition, a 'nutrient sensing pathway' (the hexosamine biosynthetic pathway), which regulates leptin gene expression, will be discussed as a possible mechanism by which exercise-induced energy deficit may modulate serum leptin concentrations.
Plasma leptin and energy expenditure during prolonged, moderate intensity, treadmill exercise
2013
Background: Current literature shows conflicting results regarding the possible direct role of exercise on leptin concentrations, mainly because of a non-homogeneous level of energy expenditure (EE) and the lack of standardization of energy balance. Aim: The aim of the study was to evaluate the effect of exercise duration and its corresponding EE on leptin levels, during prolonged treadmill exercise, in a well-controlled laboratory setting. Materials and methods: Seven young trained males underwent a 4-h treadmill exercise. The starting intensity was set at 65% of maximal oxygen consumption. At the start of the test and throughout the exercise, venous blood samples were drawn for the assays of leptin, glucose, free fatty acids (FFA), cortisol, epinephrine (E) and norepinephrine (NE). Hourly and total EE was monitored with gas analysis. Results: Plasma leptin levels decreased from 1.10±0.15 to 0.85±0.26 µg/l (p<0.01) at the end of the exercise, reaching a significant reduction already after the second hour. FFA and cortisol showed a progressive significant increase, while glucose did not significantly change throughout the test. Plasma E and NE significantly increased at all sampling times compared to basal values (48. . The randomeffects model for panel data analysis showed negative correlation between leptin, NE and the values of progressive EE (r 2 =0.745, p<0.05). Conclusions: Our data demonstrate that, during a prolonged moderate intensity exercise, leptin decrease is significantly related to the total EE. Further, NE concentrations seem to play an important role in the inhibition of leptin secretion. (J. Endocrinol. Invest. 36: 396-401, 2013)
Leptin, its implication in physical exercise and training: a short review
Journal of sports science & medicine, 2006
Leptin, a hormone synthesized by fat tissue had been noted to regulate energy balance and metabolism and thus to influence body weight. The influence of acute exercise and chronic exercise training on circulating leptin and its relationship with hormonal and metabolic changes that induce energy balance are presented. Research that has examined the influence of exercise under various experimental conditions on leptin and the conflicts in the literature are presented. It appears that a significant caloric perturbation (> 800 kcals) is necessary for acute exercise to result in a significant reduction in leptin. In contrast, exercise training can result in a leptin decline but typically this manifests a reduction in adipose tissue stores. In addition, future directions are presented. Key PointsPhysical exercise and training have both inhibitory and stimulatory effects on leptin.Exercise with energy expenditure higher than 800 kcal can decrease leptinemia.Acute training may cause a de...
Hormone and Metabolic Research, 2014
cise in relation to energy expenditure [11]. In normal as well as in obese subjects, a period of prolonged physical training also promotes a decrease in leptin [12, 13]. Regular exercise is an important strategy in the management of obesity, together with hypocaloric diet and appropriate lifestyle. The aim of this study was to elucidate in obesity the behaviour of leptin after a comparable type of training at work loads of different intensity, that is: 1) after exclusively aerobic work, and 2) after aerobic work plus a bout of anaerobic work. On the basis of previous observations on GH and nonesterified fatty acids (NEFAs) [14, 15], we might presume different behaviours of leptin with regard to differences in quantity of physical training.
Intensity of Acute Exercise Does Not Affect Serum Leptin Concentrations in Young Men
Journal of Cardiopulmonary Rehabilitation, 2001
Purpose: We examined the effects of exercise intensity on serum leptin levels. Methods: Seven men (age = 27.0 yr; height = 178.3 cm; weight = 82.2 kg) were tested on a control (C) day and on 5 exercise days (EX). Subjects exercised (30 min) at the following intensities: 25% and 75% of the difference between the lactate threshold (LT) and rest (0.25 LT, 0.75 LT), at LT, and at 25% and 75% of the difference between LT and peak O V 2 (1.25 LT, 1.75 LT). Results: Kcal expended during the exercise bouts ranged from 150 ± 11 kcal (0.25 LT) to 529 ± 45 kcal (1.75 LT), whereas exercise + 3.5 h recovery kcal ranged from 310 ± 14 kcal (0.25 LT) to 722 ± 51 kcal (1.75 LT). Leptin area under the curve (AUC) (Q 10-min samples) for all six conditions (C + 5 Ex) was calculated for baseline (0700-0900 h) and for exercise + recovery (0900-1300 h). Leptin AUC for baseline ranged from 243 ± 33 to 291 ± 56 ng~mL-1 X min; for exercise + recovery results ranged from 424 ± 56 to 542 ± 99 ng~mL-1 X min. No differences were observed among conditions within either the baseline or exercise + recovery time frames. Regression analysis confirmed positive relationships between serum leptin concentrations and percentage body fat (r = 0.94) and fat mass (r = 0.93, P < 0.01). Conclusion: We conclude that 30 min of acute exercise, at varying intensity of exercise and caloric expenditure, does not affect serum leptin concentrations during exercise or for the first 3.5 hours of recovery in healthy young men.
International journal of obesity and related metabolic disorders : journal of the International Association for the Study of Obesity, 1999
The effects of short-term moderate physiological changes in energy flux and energy balance, by exercise and over- or underfeeding, on a 24h plasma leptin profile, were investigated. Subjects were studied over 24h in four randomized conditions: no exercise/energy balance (energy intake (EI)=energy expenditure (EE)=11.8+/-0.8 MJ); exercise/energy balance (EI=EE=15.1+/-0.6 MJ); exercise/negative energy balance (EI=11.8+/-0.8 MJ, EE=15.1+/-0.8 MJ); exercise/positive energy balance (El=18.6+/-0.7 MJ, EE=15.1+/-0.6 MJ). Eight healthy, lean men (age: 23.5+/-7.0y, body fat 14.1+/-5.4%, body mass index (BMI): 21.4+/-2.3 kg/m2). Blood was sampled every hour during the daytime (09.00-23.00h) and every two hours during the night (01.00-09.00h) for analysis of plasma leptin, insulin, glucose, FFA and catecholamines. Plasma leptin levels were highest around 01.00h (mean+/-s.e.m. 4.9+/-2.0 ng/ml) and lowest around 11.00 h. (2.3+/-0.7 ng/ml). An increased 24h EE, induced by exercise under condition...
We examined the leptin response and related hormones during and after two sub-maximal exercise protocols in trained and untrained subjects. During this study, plasma concentrations of leptin [Lep], insulin [I], cortisol [C], growth hormone [GH], glucose [G] and lactate [La] were measured. 7 elite volleyball trained players (TR) and 7 untrained (UTR) subjects (percent body fat: 13.2 ± 1.8 versus 15.7 ± 1.0, p < 0.01, respectively) were examined after short and prolonged sub-maximal cycling exercise protocols (SP and PP). Venous blood samples were collected before each protocol, during, at the end, and after 2 and 24 h of recovery. SP and PP energy expenditures ranged from 470 ± 60 to 740 ± 90 kcal for TR and from 450 ± 60 to 710 ± 90 kcal for UTR, respectively.
Acute Effects of Exercise on Circulating Leptin in Lean and Genetically Obesefa/faRats
Biochemical and Biophysical Research Communications, 1999
and genetically obese animals are not completely understood. In particular a relation has been proposed between energy metabolism and leptin. However, it is not clear how energy expenditure and leptin are related under exercise in lean and obese animals. To clarify these aspects we investigated lean and genetically obese (fa/fa) Zucker rats undergoing a single bout (30 min) of swimming and measured several biochemical and hormonal parameters of energy metabolism and leptin changes throughout the study. Moreover ob-gene expression in adipose tissue was also measured. Our results showed that plasma leptin is decreased by 30% at the end of exercise in lean animals while resulting unaffected in obese animals. Leptin changes in lean rats are concomitant with the peak of NEFA and glycerol release from adipose tissue rather than with the reduction of plasma insulin. Ob-gene expression in adipose tissue was markedly increased in fa/fa compared to lean rats, but was not modified by exercise both in lean and obese animals. In conclusion our data show that leptin changes during exercise are related to lipolytic events in adipose tissue and support a link between leptin and energy expenditure.
Acute leptin response after high intensity interval and moderate intensity continuous runs
2020
The possible direct role of exercise intensity and duration on leptin concentrations is conflicting. The aim of this study was to evaluate the acute effects of high intensity interval (HIIE) and moderate intensity continuous (MICE) exercise on plasma leptin response. Seven young volunteers underwent three tests: 1) a treadmill graded exercise test to identify running peak velocity (PV); 2) HIIE: 5 × 2 min work bouts at 90% of PV, interspersed by 2 min of passive recovery and; 3) MICE: 30 min at 70 % of PV. Blood samples were drawn for the assays of leptin before and 30 minutes after HIIE and MICE. A 2-way repeated measures ANOVA showed a significant main effect of time [F(1,6) =17,52; p=0,006], no significant effect of condition (type of exercise) (F(1,6) = 0,16; p = 0,68) and no significant interaction (condition × time) (F(1,6)= 0,48, p=0,51). Leptin decreased 30 min after HIIE (t= 2,95, p=0,025) and MICE (t=4,18; p=0,005). There was no difference between the HIIE and MICE conditi...