. 2021 Oct 1;10(4):444–452. doi: 10.1007/s13679-021-00456-8

Table 1.

Considerations when designing physical activity interventions for adolescents

Goal	Goal details	Measurement	Outcomes	Example Interventions
Increase physical activity	• Frequency and timing • Intensity (light, moderate, vigorous), including relative versus absolute • Aerobic versus resistance activities	• Wearable activity trackers • Observation • Self-report	• Step count • Time spent in activity • Distance	1. Complete at least 10 min of moderate to vigorous physical activity (e.g., brisk walking or jogging) 3 times per week before dinner. Participants wear commercial activity tracker on wrist while awake. Both step count and time spent in activity captured. 2. Complete at least 15 min of resistance activities twice weekly at time of participant’s choosing. Participants self-report to investigators using two-way texting at start and completion of activity and receive encouraging feedback. Total time spent weekly and sessions per week captured.
Reduce sedentary behavior	• Context (e.g., screen time versus homework) •Pattern (e.g., interspersed or uninterrupted)	• Wearable activity trackers • Observation (not for total daily sedentary time assessments) • Self-report	• Time	1. Participants wear commercial activity trackers while awake to obtain baseline total daily (non-sleeping) time spent sedentary. Participants asked to reduce screen time by 30 min daily from baseline and provided examples of how to do so (e.g., place smartphone out of sight during dinner or before going to bed). Change in time spent in sedentary behavior from baseline to intervention end assessed. 2. Ecological momentary assessment (EMA) used to collect participant self-report of activities throughout the day, then mapped to sedentary versus active behaviors. Participants coached via an app with individualized notifications to interrupt sedentary behaviors during times at which EMA self-report identified the participant to be most sedentary at baseline. Follow-up EMA after the intervention assesses whether a greater proportion of time was reported as non-sedentary behavior.

Goal

Goal details

Measurement

Outcomes

Example Interventions

Increase physical activity

• Frequency and timing

• Intensity (light, moderate, vigorous), including relative versus absolute

• Aerobic versus resistance activities

• Wearable activity trackers

• Observation

• Self-report

• Step count

• Time spent in activity

• Distance

1. Complete at least 10 min of moderate to vigorous physical activity (e.g., brisk walking or jogging) 3 times per week before dinner. Participants wear commercial activity tracker on wrist while awake. Both step count and time spent in activity captured.

2. Complete at least 15 min of resistance activities twice weekly at time of participant’s choosing. Participants self-report to investigators using two-way texting at start and completion of activity and receive encouraging feedback. Total time spent weekly and sessions per week captured.

Reduce sedentary behavior

• Context (e.g., screen time versus homework)

•Pattern (e.g., interspersed or uninterrupted)

• Wearable activity trackers

• Observation (not for total daily sedentary time assessments)

• Self-report

• Time

1. Participants wear commercial activity trackers while awake to obtain baseline total daily (non-sleeping) time spent sedentary. Participants asked to reduce screen time by 30 min daily from baseline and provided examples of how to do so (e.g., place smartphone out of sight during dinner or before going to bed). Change in time spent in sedentary behavior from baseline to intervention end assessed.

2. Ecological momentary assessment (EMA) used to collect participant self-report of activities throughout the day, then mapped to sedentary versus active behaviors. Participants coached via an app with individualized notifications to interrupt sedentary behaviors during times at which EMA self-report identified the participant to be most sedentary at baseline. Follow-up EMA after the intervention assesses whether a greater proportion of time was reported as non-sedentary behavior.