Plasma Ghrelin Is Altered After Maximal Rowing Exercise In Elite Male Athletes

Abstract

The information of the regulatory effect of ghrelin on growth hormone release as a result of acute physical exercise is limited. To our knowledge, no studies have yet investigated the effect of short term maximal exercise on plasma ghrelin using an exercise protocol in which all major muscle groups are involved. This may cause additional energy expenditure that may be needed for plasma ghrelin to be reduced by acute exercise. PURPOSE: To investigate plasma ghrelin response to acute rowing ergometer exercise in elite male rowers. METHODS: Eight rowers performed a maximal 6,000-m rowing ergometer test (mean performance time 19 min 52 s; 1192.1±16.4 s), and venous blood samples were obtained before, immediately after and after 30 min of recovery. In addition to ghrelin concentration, leptin, insulin, growth hormone, insulin-like growth factor-1 (IGF-1), testosterone, cortisol and glucose values were measured. RESULTS: Ghrelin was significantly increased immediately after the exercise (+24.4%; p<0.05) and was decreased during the first 30 min of recovery (−17.5%; p>0.05) compared to the post-exercise level. Leptin was significantly decreased immediately after the exercise and remained significantly decreased after the first 30 min of recovery. No changes occurred in insulin concentrations. While growth hormone, IGF-1 and testosterone values were significantly increased and decreased to the pre-exercise level immediately after the exercise and after the first 30 min of recovery, respectively. Cortisol and glucose values were significantly increased immediately after the exercise and remained significantly increased during the first 30 min of recovery. There were no relationships between plasma ghrelin and other measured blood parameters after the exercise, nor were changes in ghrelin related to changes in other measured blood biochemical values after the exercise. CONCLUSION: These results suggest that acute negative energy balance induced by maximal short-term exercise elicits a metabolic response with opposite changes in ghrelin and leptin concentrations in elite male athletes.