Energy Intake and Appetite Sensations Responses to Aquatic Cycling in Healthy Women: The WatHealth Study

Background: The aim of this study was to investigate energy expenditure, food intake and appetite feelings in response to water- vs. land-based cycling exercises in healthy young women. Methods: Anthropometric measurements and body composition were assessed among 20 women who performed four experimental sessions in a randomized order: (i) a rest condition (CONT); (ii) a 30-min aqua-cycling exercise session (WAT), (iii) a 30-min land-cycling exercise session at the same rpm (LAND), (iv) a land-cycling session at the same heart rate and isoenergetic to WAT (LAND-Iso). Energy expenditure and substrate oxidation were measured by indirect calorimetry; ad libitum energy intake during subsequent lunch was assessed with appetite feelings recorded at regular intervals. Results: Energy expenditure was higher during the 30-min WAT than during CONT and LAND (p < 0.001). Carbohydrate oxidation was higher in the WAT session compared to CONT and LAND (p < 0.05). LAND-Iso duration was significantly increased (+14 min) to reach the same energy expenditure as in the WAT condition (p < 0.05). There was no differences in food intake between sessions. Conclusion: While further studies are needed to optimize the chronic energetic effects of aqua-cycling, the present study suggests that this exercise modality could represent an efficient strategy to induce acute energy deficit.