Michael Phelps doesn't train in the pool anymore; he's taken to riding a Peloton.

Phelps rides under an alias and said he's driven by competing with other riders.

Phelps recently said he pushed himself to ride 30 straight days, pedaling 500 miles and burning 28,000 calories.

Though Michael Phelps no longer misses swimming, he still has a competitive itch and a need to push his body to the limits. Instead of hopping into a pool, Phelps has taken to cycling — training on a Peloton and "hammering" out rides.

Peloton is a high-tech fitness company that allows users to access classes online without leaving their home. Their core product is expensive, costing $1,995 for the bike, but has gotten a cult following.

"We got a Peloton maybe last July, last August, and I've kinda just been really hammering bikes rides when I'm home," Phelps told Business Insider. "I just got off of a 30-day-straight kinda kick where I just wanted to see what it would do and how my body would react to it."

Phelps told Nick Zaccardi of NBC that he rode over 500 miles in those 30 days, burning 28,000 calories.

Phelps also said he rides under an alias in the online classes — he won't reveal it — and said he's driven by competing in the classes and seeing the digital "leaderboard" on the screen.

"And that's another thing where I have the competitive side of me that really comes out," Phelps said, adding: "I've had somebody next to me racing every single stroke of my life I've ever taken in the pool. It's good for me to kinda be able to push myself."

Phelps said his daily rides are now part of his routine, giving his day the kickstart he needs now that he's not training in the pool.

Peloton riders will have no way of identifying who's in class with them, but there's a chance they could be competing against the greatest Olympian of all time.