Abstract
PURPOSE The aim of this investigation was to measure plasma visfatin and ghrelin responses to a single endurance rowing training session in male competitive single scull rowers. METHODS Nine national level male rowers (20.1 +/- 1.5 yr; 183.9 +/- 4.3 cm; 81.0 +/- 5.0 kg; 10.8 +/- 3.3% body fat) completed two trials (exercise or control) on separate days. The exercise consisted of a prolonged rowing training session lasting approximately 2 h (distance = 20.7 +/- 1.4 km; HR = 133 +/- 4 bpm; intensity = 80.2 +/- 1.6% of the HR turn point) followed by a 30-min rest. Venous blood samples were collected before and after on-water rowing. The control trial consisted of rest and blood collection similar to exercise trial. RESULTS No differences were found at baseline values for plasma visfatin, ghrelin, and leptin for both trials. The estimated energy expenditure of the exercise trial was 1200-1500 kcal. Plasma visfatin (-10.0%; P < 0.05) and leptin (-20.0%; P < 0.05) were reduced, and ghrelin concentration was increased (+12.2%; P < 0.05) after a 30-min postexercise. No differences in plasma visfatin, ghrelin, or leptin over time were observed during control trial. There was no relationship between basal visfatin and body composition, energy balance, aerobic power, or blood biochemical data. Plasma visfatin (r = -0.76) and ghrelin (r = 0.75) measured immediately after the training session were related (P < 0.05) to the distance covered, and no relation was observed for postexercise leptin (r = -0.16; P > 0.05). CONCLUSION Acute negative energy balance induced by a single endurance rowing training session elicited an inverse metabolic response in visfatin and ghrelin in competitive male rowers. Our results suggest that peripheral markers of negative energy balance, such as visfatin and ghrelin, may be regarded as signals for metabolic reaction to the energy cost of acute exercise. The results of our study also suggest that an energy-deficit threshold must be met for the response to occur.
