Introduction:
Aerobic dance can reduce individual stress response levels and its psychosomatic symptoms, and increase physical fitness. The effect of social interaction and the environment is also considered prominent for reducing stress. The purpose of this study was to measure the impact of social interaction and the environment when practising aerobic dance on reducing stress among first-rate university students in Indonesia.

Methods:
The study involved 16 students (8 males and 8 females) aged 18–20 years. All participants took a series of indoor and outdoor tests. In the indoor-test phase, they did indoor aerobic dance without communicating with one another, while in the outdoor-test phase, they did outdoor aerobic dance and were allowed to interact with one another. The subjects underwent 3 measurements: salivary cortisol was assessed before and after the aerobic dance in the indoor and outdoor test; heart rate was evaluated during the aerobic dance; and rating of perceived exertion was established immediately after each participant had finished the aerobic dance.

Results:
One-way ANOVA statistical test showed a significant difference between indoor-test and outdoor-test conditions in the measurement of salivary cortisol after the intervention (p = 0.001). Independent t-test also revealed a significant difference between both conditions (p = 0.001).

Conclusions:
More communicative social interactions and conducive outdoor environments that allowed a direct contact with nature in doing aerobic dance had a significant effect in reducing cortisol awakening response in salivary cortisol measurements.