Science tells us isolating muscles (ie curling a bar to work just the biceps, or using a seated leg press machine to build quads) will certainly make those muscles bigger but there is unfortunately no correlation as to how they will perform in action. Just because you have used a leg press to make your thighs large, does not mean you can put them to work when called upon at the football game. Muscles work in conjunction with each other – period end, so to train in any other fashion creates DMO bodies (Display Model Only:). We train you to squat instead of using a leg press machine…squatting is multi-joint and multi-muscle move and is very FUNCTIONAL. And we will never ever curl a bar at CrossFit, yet you will certainly look like you do curls! When you move your couch, play a football game, run a race, go hiking, ride a bike or go boating – you would never in any scenario isolate a muscle, so please stop training like that! Stick to Functional Moves (Multi Muscle/Joint Moves)…this gets you not just looking great, but performing great too!