Behavioral management of exercise: contracting for aerobic points.

Wysocki et al. (1979) asked eight college students to sign a paper contract. Each week they earned aerobic points for walking, running, or biking. Valued items like records or cash were held as collateral. If they met the point goal, they kept the items. If not, the items were lost.

The study used a multiple-baseline design across students. Points were tallied weekly. After 12 months, the team mailed a short survey asking who was still active.

Seven of the eight students quickly raised their weekly aerobic points. Most told the researchers they were still exercising one year later. The contract plus collateral made exercise stick, at least for these students.

McCullen et al. (2025) ran a similar contract-plus-deposit setup with sedentary adults. Step counts shot up, but they dropped back to baseline once the contract ended. The newer study shows larger gains and adds reinforcement thinning, so it now supersedes the 1979 method.

Stedman-Falls et al. (2020) moved the same deposit contract into a phone app. Steps rose whether the contract was on paper or on screen, but adults liked the app more. This extends the 1979 finding to tech delivery.

Heo et al. (2008) swapped collateral for media time. High-schoolers earned internet minutes only after they hit activity goals. Activity rose and stayed high for a year. This conceptual replication shows the reinforcer can be privileges instead of objects.

If you want clients to move more, a short written contract still works, but pair it with modern boosts. Add gradual thinning, app tracking, or privilege access to keep gains after the deal ends. Draft a one-page contract, set a clear weekly target, and hold a reinforcer the client truly hates to lose.