If you're lifting weights on machines and going through the full motion, it doesn't really matter whether you focus more on the stretch or squeeze part — you'll gain about the same muscle and...

If a muscle works best when it's stretched out, it grows more when you do full movements. But if it doesn't rely on that stretched position, how far you move doesn't really change how much it grows.

Even if you cheat a little to lift heavier, your muscles still grow just as well—so maybe the key to building muscle isn’t perfect form, but just getting your muscles to work hard enough.

If you train with weight machines, you'll get stronger on those same machines better than if you trained a different way — it really helps to practice the exact move you're being tested on.

If you lift weights with machines or with free weights and do the same amount of work at the same effort level, you’ll build muscle just as well with either one — even if you’re already fit.