The influence of different tree densities on alpha waves, physical activity enjoyment, and satisfaction of late middle-aged and older adults using virtual cycling

Cave automatic virtual environment (CAVE), as a novel approach to promoting physical activity, shows great potential for improving the mental health and healthy lifestyle of older adults. Based on stress reduction theory, tree density is regarded as a main characteristic of a virtual sportscape that will affect the experience and benefits of exercising. However, the effect of tree density on the experience of exercising remains unclear. The current study was undertaken to investigate the effects of tree cover density on the alpha waves induced and the enjoyment and satisfaction derived by engaging in physical activity in a virtual environment. Eighty-seven late middle-aged and older adults were randomly assigned to one of the following conditions: a high tree density sportscape (HTDS = 36-60 %), a medium tree density sportscape, (MTDS = 20-35 %), and a control condition. Questionnaires and electroencephalogram read-outs of alpha waves were used to evaluate the changes in stress levels experienced by the participants before, during, and after 20 min of cycling. The results showed that participants exposed to an HTDS exhibited to physical activity with significantly more enjoyment and satisfaction than those in the MTDS and control groups. In contrast, the highest degree of relaxation was exhibited in the MTDS condition, suggesting that an MTDS is more effective at reducing perceived stress among late middle-aged and older adults engaging in virtual cycling. These findings demonstrate that exercising in a virtual reality setting with different densities of tree cover comes with physiological and psychological wellbeing for late middle-aged and older adults.