Using self‐tailored deposit contracts and reinforcement thinning to increase physical activity of sedentary adults

Three adults who rarely exercised put their own money on the line. They wrote deposit contracts that said, "If I miss my step goal, I lose cash."

The researchers then thinned the deal. At first, every step counted. Later, only some steps earned money back. The team tracked daily steps with a phone app.

All three people doubled or tripled their steps while the contract ran. When the money stopped, their steps dropped back to couch-potato levels.

Stedman-Falls et al. (2020) showed you can run the same deposit deal through an app and still win. Their tech version worked just as well as face-to-face meetings.

Erath et al. (2022) looks like a clash. They used remote prompts and money, yet only four of six adults walked more. The difference: McCullen added reinforcement thinning and let clients set their own deposit amount. That small tweak may explain why everyone here succeeded.

Heo et al. (2008) used tokens, not cash, and the teens kept exercising five weeks later. Their trick was making screen time depend on exercise. McCullen’s adults had no built-in backup, so the habit vanished.

Deposit contracts give you a fast boost, but the boost fades. Pair the contract with long-term tricks—intermittent money, booster contracts, or tying TV time to steps—so clients keep moving after the program ends.