With consumers increasingly casting and streaming online video to their TVs, new data reveals a surprising trend about YouTube viewers’ behavior—and it’s all about that early-week hustle.

As people continue to watch YouTube in the living room (and the game room, den, and bedroom), we’ve seen strong viewer behavior patterns emerge. The strongest? Watching YouTube content on a TV screen is a lot like watching TV content on a TV.

Most YouTube viewing on TV screens happens on the weekend. Whether the content relates to sports, animation, food, or hobbies, the behavior is the same. There’s one massive exception though: fitness content.

Tuesdays are the peak day of the week for YouTube fitness videos on TV screens, suggesting people are building sweat equity right in their own homes.

This is consistent with data released by ClassPass in 2016, indicating that Tuesday is the most popular workout day nationwide.

So what does the latest YouTube audience research prove? All those reps aren’t just being counted in the gym.

YouTube Data, U.S., classification as fitness videos was based on public data such as headlines, tags, etc., and may not account for every such video available on YouTube, Jan.–Dec. 2016.