10 Machines You Must Avoid

1 Seated Leg Extension
What it’s supposed to do: Train the quadriceps
What it actually does: It strengthens a motion your legs aren’t actually designed to do, and can put undue strain on the ligaments and tendons surrounding the kneecaps.
A better exercise: One-legged body-weight squats. Lift one leg up and bend the opposite knee, dipping as far as you can, with control, while flexing at the hip, knee, and ankle. Use a rail for support until you develop requisite leg strength and balance. Aim for five to 10 reps on each leg. (If you are susceptible to knee pain, do the Bulgarian split squat instead, resting the top of one foot on a bench positioned two to three feet behind you. Descend until your thigh is parallel to the ground and then stand back up. Do five to 10 reps per leg.)


4 Seated Pec Deck
What it’s supposed to do: Train chest and shoulders
What it actually does: It can put the shoulder in an unstable position and place excessive stress on the shoulder joint and its connective tissue.
A better exercise: Incline push-ups. Aim for 15 to 20 reps. If this is too easy, progress to regular push-ups and plyometric push-ups (where you push up with enough force that your hands come off the ground), and aim for five to eight reps.




8 Squats Using Smith Machine
What it’s supposed to do: Train chest, biceps, and legs
What it actually does: The alignment of the machine—the bar is attached to a vertical sliding track—makes for linear, not natural, arched movements. This puts stress on the knees, shoulders, and lower back.
A better exercise: Body-weight squats. See “Seated Leg Press.”

For a complete listing of all 10 machines to avoid, including the seated military press and the seated lat pull-down (behind the neck), check out the full article at BestLifeOnline.com.