Plasma Leptin Levels of Elite Endurance Runners after Heavy Endurance Training

Abstract

A decrease in testosterone levels and an increase in cortisol levels are observed in male athletes with the overtraining syndrome (OTS). Cortisol causes blood leptin levels to rise and testosterone has an inverse relationship with blood leptin levels. Therefore, we hypothesized that the hormonal changes as a result of OTS induce an increase in leptin. To test this hypothesis, we examined the relationship among changes in leptin, testosterone and cortisol in thirteen male collegiate distance runners (aged 20.3Ϯ1.1 years) before and after an 8-day strenuous training camp. Runners ran 284.1Ϯ48.2 km during the training camp. Body fat percentages and plasma glucose concentrations decreased significantly after the training. Non-ester fatty acids and total cholesterol concentrations in blood were unchanged. Serum cortisol concentrations showed a significant increase after the training camp (from 11.82Ϯ2.00 mg/dl to 16.78Ϯ3.99 mg/dl), and serum testosterone decreased significantly (from 408.0Ϯ127.6 ng/dl to 265.2Ϯ97.6 ng/dl). The ratio of testosterone to cortisol (TCR) dropped by 50% after training (from 35.62Ϯ13.69 to 16.94Ϯ8.47). These results suggest that the subjects reached a state of the OTS. Contrary to our hypothesis, plasma leptin was not significantly changed (from 1.34Ϯ0.29 ng/ml to 1.49Ϯ0.18 ng/ml). D Plasma leptin was not significantly correlated with D serum cortisol, D TCR or D fat percentage. However, D serum testosterone was positively correlated with D plasma leptin (rϭ596, pϽ0.05). Plasma leptin concentrations might modulate the secretion of testosterone in overtraining conditions. In conclusion, the change in blood leptin level is independent of the changes in cortisol, TCR and fat percentage in highly trained male athletes in the state of the OTS.

Leptin and the brain: Influences on brain development, cognitive functioning and psychiatric disorders

“…However, accounting for changes in body composition, short-term training studies did not demonstrate significant differences in leptin concentrations [207,208].…”

Anthropometric Characteristics of Ultramarathoners

“…Nonetheless, there was a significant correlation between BMI and average running speed indicating that 10 -12% of the variation in running speed is accounted for by BMI. Studies reporting BMI data for elite adult runners at the middleto marathon-distances have suggested that men average around 19.0 to 21.8 kg • m -2 [1,3,4,8,9,15,17,20,22] and women average around 17.3 to 19.8 kg • m -2 [5,17,22,24,25]. Such values for men appear within the same range as the limited BMI data previously reported for top-level ultramarathon runners of around 21.4 to 21.9 kg • m -2 [5 -7].…”

Efectos de un protocolo de entrenamiento de alta intensidad sobre marcadores fisiológicos de estrés en ratas. [Physiological effects of the stress induced by a high-intensity exercise protocol in rats].

“…A diferencia de lo descrito en otros estudios desarrollados en ratas con protocolos de ejercicio a intensidad moderada (Ishigaki, Koyama, Tsujita, Tanaka, Hori, y Oku, 2005; Lira, Rosa, Pimentel, Tarini, Arida, Faloppa, Alves, do Nascimento, Oyama, Seelaender, de Mello, y Santos, 2010), hemos detectado valores adversos en algunos marcadores de perfil lipídico en el grupo de EAI, como mayor colesterol LDL plasmático y mayores concentraciones de grasa en hígado. Tan solo los triglicéridos, presumiblemente por ser la principal fuente energética en el ejercicio, han sido menores en el grupo de ratas de EAI con respecto a las sedentarias.…”