Leptin response to acute prolonged exercise after training in rowers

The aim of this study was to determine if there is a training effect on leptin levels at rest or after prolonged exercise during an 8-month training season of rowers. Eleven trained rowers were evaluated at three sessions (control, early and late) during the season. At the early and late sessions, leptin and insulin concentrations were measured before and after 90 min of rowing exercise (70–75% maximal oxygen consumption, V̇O₂max), 120 min and 24 h afterwards. Anthropometrics data were collected at each session. Energy balance was determined on the days of exercise sessions. Resting leptin levels were not modified over the season and were in correlation with weight and body fat (P<0.05). At exercise sessions, a delayed reducing effect of acute exercise on leptin levels appeared (P<0.01 compared to pre-exercise). After 24 h of recovery, leptin levels remained lower at early (P<0.001) but not at late sessions, and a training effect appeared between early and late sessions (P<0.001). Leptin levels were correlated with energy balance at early and late sessions (P<0.05). At the two training sessions, insulin levels were decreased immediately post-exercise and at 120 min of recovery compared to pre-exercise (P<0.01 and P<0.001 respectively for the two sessions). A training effect on insulin levels appeared at 24 h of recovery (P<0.05 between early and late sessions). We concluded that rowing training over a season did not alter resting leptin levels but it attenuated the exercise-induced reduction in leptin. This could be attributed to an alteration in energy balance, although an influence of training on insulin may also be involved in the leptin response to acute exercise.