The aim of the Move@NUS pilot study is to determine the feasibility of establishing a digital intervention cohort to monitor and improve the health and wellbeing of students by encouraging them to engage in healthy movement behaviours (i.e., physical activity, sleep, and limiting smartphone-based recreational screentime).

The digital intervention cohort consists of:

• 6-months of continuous monitoring of movement behaviours, wellbeing and related factors via an Apple Watch and repeated bursts of ecological momentary assessments (EMAs).
• 3x embedded randomised controlled trials (RCTs) evaluating the efficacy of small-scale smartphone-based interventions designed to nudge participants toward participating in healthier movement behaviours.

Good overall mental and physical health and wellbeing can be promoted by engaging in healthy movement behaviours - getting adequate sleep, being physically active, and minimising recreational time spent watching a screen or being sedentary. The objectives of this study are to determine the feasibility of:

• establishing a digital cohort study and continuously monitoring health behaviours and wellbeing (and related factors) for 6 months, and
• rapidly evaluating the effects of ecological momentary interventions (EMIs; small-scale interventions that provide support in real-time, delivered via the smartwatch and app) for promoting healthy movement behaviours via a series of embedded RCTs.

The investigators will enrol up to 150 first-year university students into an innovative hybrid study that combines a digital cohort with embedded randomised controlled trials (RCTs). The digital cohort consists of 6 months of continuous observations of movement behaviours, wellbeing, and related factors via a smartwatch (Apple Watch) and repeated bursts of smartphone-based ecological momentary assessment (EMA) surveys. Throughout the 6-month monitoring period, participants are enrolled in 3 embedded RCTs evaluating the effects of EMIs that, in turn, target sleep, physical activity, and smartphone-based recreational screentime. For each embedded-RCT we assess engagement and acceptability outcomes (e.g., whether a push notification is opened, whether it is responded to), and preliminary efficacy (i.e., whether there is a between group difference in the target behaviour from pre- to post-intervention). Participants also complete traditional questionnaires at baseline, 3-, and 6-month follow-up.

Participants are eligible to join the study if they:

• are enrolled in the first year of an undergraduate degree at the National University of Singapore,
• own or use an Apple smartphone with a data plan,
• are willing to download and use a smartphone app, and
• have an Apple smartwatch (Series 6/SE or newer) and are willing to wear it continuously for the 6-month study duration.

Participants will be excluded if they are:

• pregnant, or
• planning to be overseas for more than 6 weeks (per trip) during the upcoming semester.