Tomorrow we vow to get out of bed before noon for something better than a bagel: the first-ever Sweaty Saturday. Think of it as FNO for fitness, with a portion of proceeds going toward the fight against childhood obesity. Get a move on.

What: Chaise23
Why: The chair- and bungee-based Feel the Beat class (with in-house DJ) is not your grandma’s Sit and Be Fit. Book it for serious sweat or be the first to try The Edge, a new 40-minute slide board and cardio chair class.
When: Feel the Beat, 10 a.m.; The Edge, 11:15 a.m.
Where: 40 E. 23rd St., b/t Broadway & Park Ave.

What: SLT
Why: Founder Amanda Freeman is the brains (and body) behind Sweaty Saturday. Show your appreciation with theme classes, plank contests, and package specials.
When: 8:15 a.m.-5:30 p.m.
Where: 37 W. 57th St., b/t Fifth & Sixth Aves.

What: Uplift
Why: Swap your brunch mimosa for a free postworkout one. If you’re not feeling boozy, pop open a bottle of BluePrint Juice instead to toast half-price classes all day.
When: 9 a.m.-4 p.m.
Where: 24 W. 23rd St., b/t Fifth & Sixth Aves.

What: Physique 57
Why: Whether you’re a regular or first-timer, step up to the barre with a midday class/dance party and Enlightened ice cream cooldown.
When: 12:30-1:30 p.m.
Where: 2109 Broadway, at 73rd St., ste. 206.

What: Flywheel
Why: Celebrate miles pedaled with a free Soft Serve Fruit Co. sundae, prizes for top performers in each class, and a Lavaan Dental Spa whitening treatment raffle.
When: 7:30 a.m.-6:30 p.m.
Where: 39 W. 21st St., b/t Fifth & Sixth Aves.

What: Barry’s Bootcamp
Why: You can (almost) still smell the fresh paint at the gym’s new Tribeca location. Stop by all day for regular classes and a goodie grab bag or go all out at a predinner ’80s treadmill dance party.
When: Classes, 7:30 a.m.-5:30 p.m.; dance party, 7 p.m.
Where: 1 York St., at Sixth Ave.

Photo: Les and Dave Jacobs / Getty Images