A reward as tiny as 9¢ could help people return to the gym after missing a session, new study finds

• Workout motivation is tricky to predict, according to a study on 61,293 gym members.
• Researchers found tiny incentives could prompt people to hit the gym more often.

Getting back into the gym after missing one workout may be a crucial part of sticking to a routine — and it could take as little as a nine-cent reward to get you there, according to a massive study published December 8 in Nature.

Led by researchers from the Wharton School of the University of Pennsylvania, scientists from 15 universities studied 61,293 members of 24 Hour Fitness over a four-week period. Together, the team used an experimental format called a mega study to compare 54 different strategies for getting people to the gym more often.

They found it was surprisingly difficult to predict what worked, but the data suggested that small incentives could help nudge people towards more consistent workout routines.

Small incentives can make a difference

The most effective motivation strategy in the study was offering people an extra reward for getting back in the gym after a missed workout.

All of the motivation strategies started by offering participants the equivalent of 22 cents for each check-in at the gym. But for one of the 54 groups, returning for a scheduled workout after missing a session earned them an additional nine cents, for a total of 31 cents. If they missed more than one workout, though, the bonus disappeared.

The tiny bonus prompted participants to go to the gym about 16% more often than the baseline during the four week study. Its effectiveness was likely less about the cash, and more about preventing one slip-up from derailing a whole routine, according to Katherine Milkman, lead author of the study and a professor at Wharton.

"Nine cents isn't magical. That's not enough for gas to go to the gym," Milkman told Insider. "It's about focusing attention on not having a series of lapses, saying, 'I can't be perfect but let's get back on track.'"

Gym motivation is hard to predict

Researchers were shocked by how inaccurate their predictions were, Milkman said.

Strategies they thought would work well didn't make much of a difference. For instance, it didn't help to have participants give each other workout advice, although research shows that technique can help in other contexts, like motivating students to excel at school.

Strategies, like giving participants an audiobook, did better than expected.

Researchers also overestimated how effective the motivation strategies would be overall. At best, the motivation tools increased gym visits during the study by 27%.

"We underappreciated all the obstacles in people's lives that make getting to the gym hard," Milkman said.

Most of the benefit disappeared after the study, too, suggesting the rewards need to keep coming for people to stay motivated.

"We need to think of incentives not as short term fixes, but as active tools for people's lives," Milkman said.

To boost your own motivation, make a plan and reward yourself for following it

While the study was focused on policy strategies to encourage exercise, rather than individuals, there are some helpful takeaways if you're trying to be more consistent in the gym, according to Milkman.

"Extrapolating beyond the data, there are basic best practices people can build for themselves, things that everyone can do," she said.

Making a plan of the dates and times you're going to exercise is an effective strategy for helping you stay consistent, particularly if you set a reminder about 30 minutes before a scheduled session, the study suggests.

It also helps to attach small rewards to working out, whether that's to enjoy a special treat or fun activity post-workout, or paying yourself a little cash to get to the gym.