Use these moves to build lean muscle and firm those legs fast!
Explosive moves (plyometrics) increase strength and help your body absorb impact to prevent injuries, says Juan Carlos Santana, director of the Institute of Human Performance in Florida. Warm up for 10 minutes and do two sets of eight reps twice a week.

Vertical Jumps

Level: Moderate
Stand with your legs shoulder-width apart and your arms slightly in front of you. Squat down about 45 degrees and jump up as high as you can. Land on the balls of your feet, but make sure your whole foot touches the ground before repeating immediately.

Long Jumps

Level: Advanced
Stand with your legs shoulder-width apart. Get into a quarter squat and immediately jump forward as far and as high as you can. Bring your arms in front for balance as you jump. For a more challenging move, jump forward over obstacles like cones or sticks.

Lateral Obstacle Jumps

Level: Olympian
Stand next to a step or cone with your feet shoulder-width apart and your hands in front of you for balance. Get into a quarter squat and jump as high as you can laterally over the obstacle, landing on both feet. As soon as you touch the floor, jump back the other way.