Guess Which Exercise Burns The Most Calories?

Running, of course! According to Fitbit’s new Activity Index, running is at the top of the list when it comes to calorie-burning activities. What’s more—the data-collecting website also lists running as the number-one exercise among pretty much anyone in the U.S. under 55—and that’s a lot of people!

The site also provides tips for optimizing workouts, as well as reasons behind doing different types of sweat sessions.

With this data, collected from registered Fitbit users, the company is able to answer key fitness-related questions:

1. What are the most logged workouts in key countries around the world?
2. Which activities are logged more frequently in the U.S. versus Australia?
3. What activities do women versus men participate in more frequently?
4. How do different age groups—millennials, Gen Xers and Baby Boomers—approach fitness differently?
5. When did today’s fitness crazes, such as barre classes, become popular? (Hint: It was pretty recently.)

These findings are sourced through Fitbit’s expansive aggregated and anonymized data. The mission remains to use data to motivate people; seeing the many ways others choose to stay active can help people do the same for themselves.