QUAD EXERCISE: BARBELL SQUAT4 sets, 20 reps, 225–405 poundsPHIL’S TAKE “This is an old favorite that I added back in the last couple of years. I’ve seen a lot of new growth from it.”DO IT RIGHT Setting up shop within a power rack, Phil steps underneath and up into the bar so that it rests across his upper back just above his shoulder blades, then disengages it from the supports. Stepping back into a shoulder-width stance, knees slightly bent, and toes turned out slightly, he stiffens his body and flexes his core. From there, he shifts his hips back and bends his knees to lower his body, stopping to reverse once his thighs reach a point parallel to the floor or just below. He reverses motion by forcefully extending his hips and knees, driving through his heels to reach a standing position.ERRORS & OMISSIONS The mistake most often seen in gyms nationwide is guys piling on more weight than they can reasonably control, leading to awkward (and dangerous) contortions to get the barbell up, as well as a shortening of the range of motion. The other mistake? Not doing squats at all. It’s a difficult, uncomfortable, challenging—and thus, extremely productive—exercise no one should discard out of hand.INTENSITY TIP “Adding intensity techniques for squats is really unnecessary. I don’t do anything like dropsets, partials…nothing extra, nothing fancy. I just focus on doing 20 every set, no matter what.” HAMSTRING EXERCISE: SEATED LEG CURL 5 sets, 10–15 reps, up to full stackPHIL’S TAKE “This is always cool, I like this move. It’s straightforward and efective. I make sure to hold a 1–2 second contraction at the very bottom.”DO IT RIGHT Phil sets himself in the machine with the pads again at the inward rounding area of the Achilles. Breathing deeply, he flexes both ham- strings to bring the pads downward in an arc, as far as he can go. “I use the handles on this one, because holding on means you can really squeeze out that contraction,” he says. “I’ll also sit up a little higher in the seat to make sure I have a full range of motion.”ERRORS & OMISSIONS Because you’re locking your thighs into position, you need to take extra care that it’s not causing you to hyper-extend the knees at the top. Always make sure you maintain a slight bend at the apex of the exercise, and don’t let the stack touch down between reps.INTENSITY TIP “If you don’t have the single-leg hamstring curl machine at your gym, you can do one leg at a time on either this machine or the lying leg curl. That way, you won’t have a stronger leg compensating for a weaker side.” FLEXOnline breaks down Phil Heath's leg routine, exercise by exercise. Click "Next Page" for: Leg Press and Dumbbell Stiff-Leg Deadlift!