i normally use heavy weight when performing leg extensions ( 250lbs). would i be better off to train with lighter weight with that particular exercise.?
You'd be better off doing squats, lunges, etc. Probably the single biggest waste of time in the gym is the leg ext, not to mention the imbalances it creates. I actually should like the thing. It keeps noobs off my squat rack!
I was high repping at that kind of weight on leg extensions before I started squatting but as soon as I tried to squat for the first time I couldn't lift sh*t. IMO leg extensions are almost worthless for building any kind of practical strength
My advice would be to quit the leg extensions and get to squatting or lunging and deadlifting (FREE WEIGHTS). At least one quad dominant exercise and at least one hip dominant exercise.