Fat Does Not Mean Strong Saw a guy almost fold his leg the other day in the gym trying to do heavy deadlifts. Now, I'm 6'6" tall, and have very long legs.  When I first started doing deads and rack pulls, I really had to start with lighter weight and work on form and outward leg drive so I would snap a tendon or ligament with heavier weights.  This fella thought that since he was short, he could put up heavier weight right away.  His legs were thick, but not from muscle.  He started his lift (315lbs on the bar, with ugly, puking cat form, btw) and his knees instantly went into each other, causing him to drop the weight.   I'm honestly surprised that he didn't snap something serious.  Just because you look thick doesn't mean that you are strong.  And I guarantee that his core would not have been able to support the stabilization effort had he gotten the weight to his waist.