Physical activity (5 items) is assessed using questions adapted from the 1985 National Health Interview Survey. The variable measures the sum of hours per week that the participant engages in 5 categories of activities:

1. Walking for exercise
2. Gardening or yard work
3. Calisthenics or general exercise
4. Bicycle riding (including stationary bikes)
5. Swimming or water exercises

Participants are asked if they have engaged in any of the 5 activities within the past 2 weeks and if so, the number of occasions and average minutes per occasion. Minutes in each activity are summed and divided by 120 to yield a composite measure of participation in physical activity expressed as hours per week.

NOTE: Data collection for this variable in MARS began in September 2022.