The Effects of Nature-Based Activity vs. Indoor Exercise on Cognition, Psychological, and Physiological Health

Sustained attention to response task (SART) will be used to measure sustained attention. Participants will be presented with a series of single digits (1-9) displayed one at a time on a computer screen. The digit appears in a random order at a fixed interval. They will be instructed to press the spacebar as quickly as possible every time they see any digit except the target digit (i.e., the digit 3). Participants are instructed to withhold their response when the target digit appears.

Participants' salivary cortisol will be collected using the passive drool method in sampling tubes. The samples were then be sent to the laboratory for measurement of cortisol in saliva, as an indicator for participants' stress level.

Digit span backward (DSB) will be used to measure working memory. A series of digits will be presented sequentially, and the participants will be asked to repeat them in backward order. Sequences were 2 to 8 digits, and there will be a total of 14 trials (with 2 trials for each length).

Heart and Flower Task will be used to measure executive functions. The test is comprised of three phases: (1) the congruent trials phase, where participants will be instructed to press the response button corresponding to the side where the heart appeared; (2) the incongruent trial phase, where the participants will be asked to press the opposite response button corresponding to the side where the flower appeared and; (3) the mixed phase, comprising a mix of congruent and incongruent trials. During all phases, stimuli were displayed for 750ms, and participants will have 1 second to respond accurately while holding instructions in mind, which requires a working memory function. Additionally, cognitive flexibility will be necessary during phase three, where participants will have to switch rules flexibly and inhibit responding on the same side when the flower appeared in phases two and three.

Alternate Uses Task (AUT) will be used to evaluate divergent creative thinking and cognitive flexibility. Participants will be provided with two items (i.e., a tennis ball, a coffee cup)) and they will be required to come up with as many alternative uses for it as they can, in 2 minutes. The responses will be evaluated on four components: (1) fluency, refers to the total number of non-repeated, appropriate responses, and any responses that were infeasible, vague, or similar to the common use will be discarded; (2) flexibility, refers to the number of different topics or categories of responses; (3) elaboration, refers to the level of detail and development of each idea, measured by the average number of words per response; (4) originality, refers to the statistically uncommon response when compared to the overall data set.

Positive and negative affect schedule (PANAS) is a self-report tool that consists of 20 items, where 10 items measure positive affect (PA) and 10 items measure negative affect (NA). Participants will rate their affect over the past week on a 5-point Likert scale from 1 (not at all) to 5 (extremely). The scores for PA and NA are calculated by adding up the items that measure the respective constructs, with scores ranging from 10 to 50. Higher scores indicate higher levels of PA or NA.

Perceived stress scale (PSS-10) will serve as a subjective measure of participants' stress levels where it measures the degree to which an individual has perceived life as unpredictable, uncontrollable and overloading over the past week. Participants will report how they felt on a 5-point Likert scale from 0 (never) to 4 (very often). The score is obtained by summing across all items (with reverse items being reversed-score), higher scores indicate higher levels of perceived stress.

The blood pressure (BP) of participants (both diastolic and systolic BP) will be measured using a standard sphygmomanometer. A sphygmomanometer is a non-invasive measurement of bodily arousal.

Weight measured using TANITA body composition scale. Reported in kg.

Measured via TANITA body composition scale, and reported in kg.

Estimated body fat proportion measured using TANITA body composition scale, reported in %.

Rating provided by TANITA body composition scale indicating estimated visceral fat level. This will be reported in unitless scale rating from 1-59.

Percentage of body weight that is water, measured by TANITA body composition scale, reported in %.

Estimated daily caloric requirement provided by TANITA body composition scale based on resting metabolic rate. Reported in kcal/day.

Age estimation based on metabolic profile, as calculated by TANITA body composition scale. Metabolic age will be reported in the unit of 'years'.

Nature-relatedness scale (NR-6) will be used to measure one's subjective relatedness to the natural environment. Participants complete 6 items, on a 5-point Likert Scale (with 1 = strongly disagree, 5 = strongly agree). Nature-relatedness will serve as a covariate (will only be measured once).