If you're a guy who already lifts weights, using free weights or machines for 8 weeks will both help ease joint pain in your arms and legs — and neither one is better than the other at doing it, as long as you lift carefully and move through the full range of motion.

If you're already used to lifting weights, whether you use free weights or machines, you'll likely feel about the same amount of less joint pain in your arms and legs after 8 weeks of training.

For exercises that move just one joint—like bicep curls—lifting heavier weights leads to better strength gains than lifting lighter weights, even if both are done until exhaustion.

Whether you use machines that change resistance as you lift or keep the same weight all the way through, after 20 weeks of training, healthy men gain about the same strength and muscle size either way.

Doing extra arm isolation exercises like bicep curls and triceps extensions doesn't help you get stronger or build more arm muscle than just doing big compound moves like bench presses and pull-downs — at least not for beginners after 10 weeks.

If you do heavy weight training for eight weeks, your thigh muscles get stronger—no matter if you use a special band to restrict blood flow after your workout or not.