“Effects of Aquatic Exercise on Appetitive Responses in Adolescents With Obesity: An Exploratory Study”, 2023-06 ():
Aquatic exercise has been suggested as a beneficial modality to improve weight loss, cardiorespiratory fitness and quality of life in adolescents with obesity; however, its impact on appetite control in youth remains unknown.
The aim of this preliminary study was to examine the effect of an acute aquatic exercise session on energy intake (EI), appetite feelings and food reward in adolescents with obesity. 12 adolescents with obesity (12–16 years, Tanner stage 3–5, 9 males) randomly completed two conditions: (1) control (CON); (2) aquatic exercise session (AQUA). One hour before lunch, the adolescents stayed at rest outside the water in a quiet room for 45 min on CON while they performed a 45-min aquatic exercise session on AQUA. Ad libitum EI and macronutrients were assessed at lunch and dinner, subjective appetite feelings taken at regular intervals, and food reward measured before and after lunch.
Paired t-test showed that EI was not different between CON and AQUA at lunch (1333 ± 484 kcal vs 1409 ± 593 kcal; p = 0.162) and dinner (528 ± 218 kcal vs 513 ± 204 kcal; p = 0.206). Total daily ad libitum EI was statistically-significantly higher on AQUA (1922 ± 649 kcal) compared with CON (1861 ± 685 kcal; p = 0.044) but accounting for the exercise-induced energy expenditure, relative energy intake did not differ (2263 ± 732 kcal vs 2117 ± 744 kcal, p = 0.304). None of the appetite feelings (hunger, fullness, prospective food consumption and desire to eat) and food reward dimensions were statistically-significantly different between conditions.
These preliminary and exploratory results suggest that an acute aquatic-exercise session might not induce energy compensatory responses in adolescents with obesity.
[Keywords: exercise, appetite, energy homeostasis, food intake, food reward]
…Interestingly, while land-based moderate-to-high intensity exercise performed an hour before a meal has been shown to reduce subsequent food intake in adolescents with obesity, our results seem to indicate that this effect might not exist while exercising immersed. Indeed, although the 45-min aquatic session was performed at moderate-to-high intensity (mean heart rate 68 ± 8% of maximal heart rate), the adolescents’ EI was not modified. These results might suggest the potential role played by the mechanical load of body mass on post-exercise appetitive responses when exercising on land (especially during weight-bearing activities such as running and resistance training), which is reduced when immersed due to water density and Archimedes’ Law stating that liquid exerts a buoyant force that allow an immersed body to float. This indeed recalls the results from et al 2018 who showed a negative association between BMI, body mass, fat-free mass and fat mass and post land-based exercise EI in adolescents with obesity, already suggesting the potential importance of the mechanical load on appetitive responses to exercise in this population. This is reinforced here by the absence of correlation between these anthropometric and body composition variables and the adolescents’ post-exercise intake. The relationship between mechanical load, body mass and food intake has been explored in preclinical studies ( et al 2021; et al 2018) and seems to suggest that artificially increasing loading results in reducing food intake, and conversely. Results from non-weight bearing activity such as swimming ( et al 2010; et al 2020), which increase subsequent energy intake, as well as the increase in total energy intake observed here in response to a water aerobics session, are consistent with the concept of an inverse relationship between mechanical load and post-exercise food intake. This relationship between mechanical load and food intake remains poorly understood in humans and the aquatic environment could allow a more accurate assessment of the effect of a decrease in mechanical load. However, beyond the decrease in apparent weight resulting from buoyancy, other properties of water could impact these appetitive responses.