Leptin and Exercise

Abstract

Short-term exercise (<60 min) studies suggest that leptin concentrations are not acutely affected in healthy males and females. Most reports of reductions in serum leptin may be attributed to circadian rhythms or hemoconcentration. For long-term (≥60 min) exercise, a reduction in leptin concentrations reported from 1 to 3 hr of running or cycling has been attributed to diurnal reduction in circulating leptin, independent of exercise. Exercise that produces a sufficient energy imbalance (kilocalorie intake versus kilocalorie expenditure) suppresses 24-hr mean and amplitude of the diurnal rhythm of leptin in women. Suppression of leptin concentrations may be counterbalanced by feeding and may explain consistent reports of reductions in leptin concentrations following extreme bouts of exercise such as marathons or ultramarathons. In addition, leptin concentrations are reduced 48 hr after long-term aerobic exercise and long-term resistance exercise is associated with delayed leptin reduction 9 hr postexercise. Training studies have documented that short-term exercise training (≤12 weeks) does not affect leptin levels, with the exception of patients with type 2 diabetes. Exercise training protocols that result in reduced fat mass will lower leptin concentrations, thus, most investigators have reported leptin concentrations after accounting for fat loss. There are disparate findings concerning long-term (>12 weeks) training studies, with a number of studies finding no effect of training on leptin concentrations other than effects induced by fat loss, and other studies finding reductions in leptin concentrations after accounting for fat loss. Exercise training-induced reductions in leptin levels have been attributed to alterations in energy balance, improvements in insulin sensitivity, alterations in lipid metabolism, and unknown factors. Hormone replacement does not seem to affect leptin adaptations to training. Patients with type 2 diabetes show delayed effects of short-term resistance exercise on leptin concentrations, reduced leptin levels with long-term training, and appear to be more sensitive to training-induced leptin adaptations than other populations.

Low-intensity exercise training delays onset of decompensated heart failure in spontaneously hypertensive heart failure rats

“…No changes in leptin levels in HF have been found (67), and findings of decreased leptin in disease states associated with CHF, such as cachexia, further cloud the issue (15). Discrepancies also exist in the literature in regard to the effects of exercise training on leptin levels (27). Several studies have shown a decrease in leptin after chronic exercise training.…”

The Effects of 3000 Meters Swimming on Serum Level of Leptin and Glucose Under 2 Different Intensities: Continuous and Intermittent

“…The reports on the leptin reaction to the physical activity are confusing. The majority of the research indicates a decrease or lack of change in leptin level in reaction to short periods of physical activity (one session) (7). Decrease in the level of leptin in male athletes can be expected after two separate exercise tests in which the level of energy consumption is 800 to 1500 kcal.…”

Time of physical exercise practice after injury in cervical spinal cord-injured men is related to the increase in insulin sensitivity

“…3,4 Physical exercise has been suggested as an excellent mechanism for the mobilization of adipose tissue and reduced risk of chronic diseases, including people with SCI, possibly due to reduced secretion of leptin and CRP. 3,5,6 In athletes without lesions, the relationship between serum leptin and body fat is contradictory. Some studies reported that the variation in leptin concentration during exercise was related to variation in fat mass.…”

“…Some studies reported that the variation in leptin concentration during exercise was related to variation in fat mass. 5,7 However, more recent studies revealed that, regardless of body fat mass change, serum leptin levels are different in athletes 8,9 and in mice. 10 Previous investigations have shown the beneficial effects of physical training on insulin sensitivity in both healthy and glucose-intolerant subjects.…”