One of the best ways to build bigger, stronger quadriceps: the leg extension machine. It zeros in on your quadriceps by preventing other muscles from helping.

But what happens when you don’t have a leg extension machine available? Maybe you’re on the road or you work out at home or the guy wearing a sweat headband has parked his butt on the machine for the past 30 minutes.

Then use the bodyweight versions show in the video above instead. Gaddour calls them “natural leg extensions,” and they isolate your quads to give you a fantastic “pump.”

“Your quads will be under max metabolic stress to ignite growth,” says Men’s Health Fitness Director BJ Gaddour.

Every time you do them, try to boost the number of reps you do or increase the length of time you can do them without stopping.