Objective This study explored the improvement and physiological mechanisms of moderate-intensity aerobic exercise combined with multisensory stimulation on emotions through randomized controlled trials.

Methods The 1^st experiment employed a 2 (time: pre-test, post-test) × 2 (visual stimulation only, audio-visual-olfactory combined stimulation) two-factor mixed design, 48 participants were grouped randomly and conducted a 10-minute moderate-intensity aerobic exercise experiment. Because of the visual stimulation is the basic sensory stimulation method in multisensory stimulation, the 2^nd experiment used a two-factor mixed design of 2 (time: pre-test, post-test) × 4 (audio, olfactory, audio-then-olfactory, and olfactory-then-audio stimulation), and 64 participants were recruited and conducted a 10-minute moderate-intensity aerobic exercise experiment.

Results Experiment 1: 1) After exercise, the positive and negative emotion scores of the audio-visual-olfactory group were significantly higher than those of the visual-only group; 2) after exercise, the root mean square of successive differences (RMSSD) and high frequency (HF) of the audio-visual-olfactory group were significantly higher than those of the visual-only group, and the systolic pressure (SBP) was significantly lower than that of the visual-only group. Experiment 2: 1) After exercise, the positive emotion score of the audio group was significantly higher than that of the olfactory group and the olfactory-then-audio group; 2) after exercise, the negative emotion scores of the audio group and the audio-then-olfactory group were significantly lower than those of the olfactory group; 3) the mean decrease of blood pressure (BP) in the olfactory group and the audio-then-olfactory group were greater than that in the audio group and the olfactory-then-audio group, and the mean decrease of low frequency (LF), HF, RMSSD, and standard deviation of the nn intervals (SDNN) were smaller than those in the audio group and the olfactory-then-audio group, but the differences did not reach significance.

Conclusions Moderate-intensity aerobic exercise combined with single or multiple sensory stimulations can effectively alleviate negative emotions, but only multisensory stimulation can effectively enhance positive emotions, the reduction of parasympathetic nerve activity depletion is the potential physiological mechanism. In the combination of aerobic exercise and multisensory stimulation, auditory stimulation is better than olfactory stimulation in improving subjective emotional experience. Only when the three senses of vision, auditory, and olfaction are simultaneously stimulated, the depletion of parasympathetic nerve activity is effectively reduced. When two senses are stimulated, the effects of different combinations or sequences of stimulation are not significant.