In the brief clip, Grylls ups the ante from an earlier fitness challenge involving toe-to-bar movements, this time doing a series of ‘hand to toes’ while hanging upside down from a pair of gravity boots. “If you completed the last challenge of 20 x ‘toe to bars’, then here is a new one: 10 ‘hand to toes’... the challenge is set!” Grylls wrote in the post’s caption. For those who complete the challenge and let him know in the comments, Grylls added, he’ll pick one winner and give them a call—provided they also follow his YouTube channel.
Unless you already boast some serious core strength, however, you might want to sit this one out. “This is a lot harder than you may think, and it's not just abs. It requires a ton of glute control, and eccentric ab control, because gravity boots are prone to leaving you with some swing when you lower,” says Men’s Health fitness director Ebenezer Samuel, CSCS. “If you don't control that, you could slip off your bar.”
If you’re still planning to give it a shot, Samuel advises taking your time with these—and stopping a rep earlier than you may think you’re able. “If you go to fatigue, you'll have trouble dismounting. Focus, too, on not collecting momentum and 'swinging' your hands up to your feet,” he says. “Tighten your abs and let them slowly drive you up on each rep.”
Watch the video here:
This article originally appeared on Men's Health US.