Paying or requiring eight gym visits a month raised later attendance

The study

1. 01

   Who took part

   120 students at the University of Chicago took part in study 1. Study 2 had 156 first- and second-year students at the University of California, San Diego. Twelve who missed later meetings were left out.

2. 02

   What they did

   Study 1 had three groups of 40: a handout only, $25 for one visit, or $25 plus $100 for eight more visits. Study 2 paid everyone $175 for three measurement meetings, and required one group to visit the gym once, another eight times. The third group had no gym requirement.

3. 03

   What happened

   In study 1, the eight-visit group averaged about 1.2 gym visits a week, against about 0.6 for the handout group. In study 2, it averaged about 1.5 visits a week, against about 1.1 for those with no requirement. Over 20 weeks, weight and body fat improved more for the eight-visit group, but blood pressure did not.

What the study found

1. HelpedGoals

   Students paid for eight gym visits went more often; one paid visit made little difference.

   • Rule: Get a reward or payment for doing ittested

   Randomised trial of 276 university students in two studies · vs students who got only a handout · behaviour was recorded · ⚠ only counted people who finished

2. HelpedGoals

   Eight required gym visits helped only people who had not gone regularly, and one visit did not.

   • Action: Set a specific goaltested

   Randomised trial of 276 university students in two studies · vs people with no gym requirement · behaviour was recorded · ⚠ only counted people who finished

3. MixedOther outcomes

   After 20 weeks, weight, waist and body fat improved more for the eight-visit group, but blood pressure did not.

   • Action: Set a specific goaltested

   Randomised trial of 276 university students in two studies · vs people with no gym requirement · behaviour was recorded · ⚠ only counted people who finished

Source