The Difference that Nine Cents Can Make

At a national fitness chain, 61, 293 members participated in a mega study. Including 30 scientists and 54 different “nudges,” the experiment quantified how well interventions worked. The interventions encouraged exercise.

Exercise Nudges

The devices ranged from one financial reward for signing up to a sequence of texts that related to social norms. Many involved getting points that had a small dollar equivalent.

You might be given a reward just for enrolling in an exercise program. Others received a scheduler that pre-planned gym visits and then text reminders. Through a third approach, receiving an audiobook, participants could listen during a workout. A fitness revision alternative was offered through which people could tweak their original plans. Some signed a pledge. The social norm initiative used texts to remind participants that an increasing number of people were exercising regularly.

There were 54 possibilities. But you get the picture.

The one device that worked the best was a bonus for returning after a missed workout. The bonus was just 425 points, equal to 31¢. Whereas you would get 300 points for attending at the planned time, you got 425 if you returned after missing a session. We are just talking about 9¢ extra. However, gym visits increased by 16%.  The key seemed to be avoiding a series of missed workouts. Coming back quickly was important.

Our Bottom Line: Commitment Devices

Behavioral economists like to know about commitment devices. As the incentives that encourage us to stick with an activity, they help us to understand the demand side of markets.

In the past, at econlife, we’ve looked at temptation bundling. With temptation bundling, we combine our “wants” and “shoulds.” Temptation bundling pairs your indulgent wants with something that is good for you. You wind up with less of the “wants” and more of the “shoulds.” Done alone, each activity has less utility. Done together they create a value boost.

We’ve also considered piggybacking where we “attach” a new task to one that we habitually do. The result is a cue. After what we usually do, we have something that is supposed to come next.

But now we know what might work  best. Just don’t skip what you need to do.

My sources and more: Thanks to behavioral economist Dan Ariely for alerting me to the exercise nudges in this Penn study, here and here. Excerpts from the paper are here. But also we have looked at lots more that University of Pennsylvania Professor Katy Milkman has taught us.