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 ...

Walk into any gym and you’ll see people lined up to use the seated row machine, pulling heavy weights toward their chest with what looks like perfect form. But this popular piece of equipment might be ...

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.