Ryan Seacrest -- My Yacht Will Run Laps Around Yours

When Ryan Seacrest needs a workout on the open sea, he doesn't settle for a treadmill ... he just takes some laps on his massive lido deck.

We got Ryan and his model girlfriend Shayna Taylor in Saint-Tropez Thursday getting their morning run in ... without ever leaving the confines of their multi-million dollar sea castle.

There will be no Gold's Gym for Ryan, who's making his "American Idol" money work for him in many ways on the French Riviera.

OK, it may not be Bill Gates-level cash ... but Ryan's yacht certainly gives Mr. Microsoft's a run for his money.

The all-black outfits they're sporting seem appropriate for maximum water loss ... but from the looks of it, he hasn't even broken a sweat yet.

Think you two need another lap! It's OK, we'll wait.