Effects of a Blended Indoor and Outdoor Physical Exercise Program on Depressive Symptoms in Hong Kong Older Adults

Effects of a Blended Indoor and Outdoor Physical Exercise Program on Depressive Symptoms in Hong Kong Older Adults: a Randomized Controlled Trial

Depression is a mental health problem often occurring in the elderly. Performing physical exercise is a key element in decreasing depressive symptoms in older adults. Most studies investigating depression and physical exercise have focused on structured exercise comprise of one or two exercise components and based on the clinical patients associated with major depression. There is limited research combining multicomponent (aerobic+resistance+balance) in an exercise program and targeting non-clinical adults with depressive symptoms, with even less available for older adults.

More attention has been paid to the role of outdoor exercise on human health. Exercise in a natural environment may provide greater physiological and psychological benefits compared to indoor exercise. Findings demonstrated that green exercise provides double the beneficial effect on improving depression among adults. Although green exercise shows effects on the improvement of depression, recently a review has indicated that structured exercise programs in older adults with depressive symptoms were mainly conducted in the indoor environment. Compared with outdoor exercise which is easily influenced by the weather and with low access of available facilities, indoor exercise is more comfortable, quiet, and convenient to operate especially for older adults. Considering the high relevance between nature and mental health, the combination of indoor and outdoor exercise programs might be able to maximize intervention effectiveness while maintaining the benefits for each type of intervention.Therefore, more rigorous RCT studies in this field are needed, particularly for non-clinical older adults with depressive symptoms.

The 16-week double-blinded RCT (2 sessions/week, 90 min/session) will include community-dwelling older adults aged 60 to 74 years old with depressive symptoms. Participants will be randomized to one of three groups (a blended indoor and outdoor group, an indoor-only group or a control group) using 1:1:1 allocation ratio. Structured exercise training with multicomponent (aerobic, muscle strength, balance) will be conducted in two intervention groups. The intervention effects will be evaluated on depressive symptoms, physical fitness, physical activity enjoyment and connectedness to nature. All measured data will be collected at the pre-intervention, post-intervention, and 3-month follow up stages.

Inclusion Criteria:

• 60 to 74 years at the start date of the project.
• Chinese version of Geriatric Depression Scale (GDS-C) scoring 5-15 (i.e., mild to serve level of depressive symptoms).
• Passing the PAR-Q plus screening or with the physician's approval for readiness to participate in high-intensity exercise.

Exclusion Criteria:

• Having cognition impairment regarded by specialists.
• are attending other health projects related to physical exercise.