Four-time Mr Olympia, Jay Cutler didn’t just “quad stomp” his way to bodybuilding immortality, he flexed a huge set of guns that blew away all other challengers too. And, in a recent Instagram post, the big man shared how he armored up those arms. The answer? Not so much fat tips, as fat grips.

“Fat Grips,” says the Olympia legend. “You’ve seen me use these a million times. I’ve been using these since 2008. That’s interesting in itself, because having won the ‘O’ in 2006, and 2007, Cutler would take a break from the podium for a year, before returning to the top spot in 2009 and 2010. So, 2008 must have been one heck of a successful training year.

“We talk about grip strength, and we talk about working the brachialis, but how do we get the biggest arm pump possible?” asks the icon. For the uninitiated, the brachialis is the muscle in your upper arm that sits underneath the biceps brachii, and helps with elbow flexing. Developing this muscle also contributes to the overall size of your arm. “Now, I’m going to show you guys a movement using the Fat Grips,” explains your dream gym partner.

Jay Cutler Uses Fat Grips for the Ultimate Arm Day Hack

Fat Grips, or Gripz, to use one trademark, are used by countless athletes from pro bodybuilders to CrossFit competitors. Charles Poliquin, a trainer of more than 400 Olympic athletes says that Fat Grips or other grip thickening accessories build bigger and stronger arms by recruiting more muscle fibers, leading to greater results.

For those who are ready to get a grip on their training, Cutler provided a demonstration by placing the accessories on some 40 pounds dumbbells (other weight are available!) and illustrated exactly how they thicken up the grip.

“So, this is gonna bring a lot more stimulation to certain parts of your muscle fibers,” explains Cutler. “It’s an ego buster,” he adds, because lifting with a wider grip will make the weight feel heavier. In the video Cutler reps out some bicep curls. “Get that really good squeeze,” he advises. “Focus on eight to twelve repetitions (the range for muscle building). Now, like I said, it’s going to be a lot harder. These are going to be a lot harder to do (than with a thinner grip), and you are going to get some soreness obviously in the forearms and you’re gonna get that crazy pump, but that pump is going to go up the arm,” concludes Cutler.

Now you’ve got the hack, try it for yourself.

For more tips follow Jay Cutler on Instagram.