"Too few football players perform single-leg activities," says Brian Grasso, a performance coach in Chicago who has trained numerous pros.
"This move develops strength where games are won or lost: in the muscles that extend the hips." Bend one knee 90 degrees and rest the foot of that leg behind you on a bench. Bend your hips and the knee of the standing leg to lower your body as far as possible, but don't allow your torso to lean forward. Reverse the motion to come back up. That's one rep. Perform 3–4 sets of 8–10 reps on both legs, resting 60 seconds between sets.
To develop sport-specific speed: Practice lateral movement. "Rather than doing wind sprints for conditioning," says Grasso, "do lateral work that enhances endurance and your ability to move side-to-side on the field." Here's one drill: Get some cones and head to the park. Make a square with the cones, setting them 10 yards apart. Shuttle your feet to move laterally from one cone to another and back as fast as you can. Rest 30–45 seconds and repeat 8–20 times (depending on fitness).
To explode off the line: Integrate lower-and upper-body exercises. To beat an offensive lineman, you need a combination of hip, leg, shoulder, and chest power. Train these muscles all at once with moves that fuse lower- and upper-body work, such as a stepup combined with a medicine ball throw (step up onto the bench and throw the ball), or a clean and press. The better you train these muscle groups to work together, the more you'll look like a bullet train speeding toward paydirt.