Liking of Sweetness and Amount of Accidental Swallowing are Associated with the Ergogenic Effect of Mouth Rinses on Walking Energy Expenditure in Recreationally Active Men.

This study aimed to evaluate the effect of mouth rinsing with solutions consisting of binary and reciprocal combinations of sucrose and sucralose on walking energy expenditure. Ten recreationally active men participated in a randomized, double-blind where feasible, within-subject study with five conditions, in which they rinsed with four sucrose-sucralose solutions (sweetness ratios: 1:1, 1:6, 6:1, 6:6) and a control solution during a moderate-intensity 60-minute walking. We measured energy expenditure, heart rate, respiratory exchange ratio and perceived effort. We also assessed ratings of internal state, sweet-liking phenotypes of the participants, and the perception of the solutions. Perceived sweetness in the solution with 1:1 sweetness was significantly lower than the others (except control), and the 1:6 and 6:1 solutions were equi-sweet. Mouth rinse solution did not significantly affect walking energy expenditure and internal state perception (p > 0.05). We unexpectedly observed an interaction between sweet liker phenotype and the amount of swallowed solution (p = 0.021), but this did not affect energy expenditure. However, the amount of swallowed solution was associated positively with rate of perceived effort (p = 0.008), negatively with walking energy expenditure (p = 0.034). We conclude that mouth rinsing with different proportions of sucrose-sucralose and total sweetness did not improve walking energy expenditure. We unexpectedly observed that participants that like sweet solutions in general may swallow more of the mouth rinses, and in turn how much they swallow of the mouth rinse is related to perceived effort and physiological variables.