Leg extensions are isolation exercises that target your quadriceps, generally performed with the aid of a leg extension machine. This machine requires you to lift your lower legs by extending your knees against weighted resistance from a seated position.
Train Today for Tomorrow's Challenges. More Training Info > Free Weight Leg Alternatives. Free Weight Leg Alternatives to Leg Extensions and Leg Curls. Q: I hear that machine leg extensions and curls aren't the best for sport training; what would some free weights alternatives be?