Free weights include dumbbells, barbells, medicine balls, sandbells, and kettlebells. Unlike weight machines, they do not constrain users to specific, fixed movements, and therefore require more effort from the individual's stabilizer muscles. It is often argued that free weight exercises are superior for precisely this reason. For example, they are recommended for golf players, since golf is a unilateral exercise that can break body balances, requiring exercises to keep the balance in muscles.[27]
Now, while all three are definitely beneficial to the process, I’d consider metabolic stress and muscular damage to be of secondary and tertiary importance, respectively. In addition, they are also things that will pretty much take care of themselves when implementing the workout guidelines and recommendations we’ve already covered (namely for volume, rep ranges, rest periods and exercise selection).

Creatine is produced endogenously at an amount of about 1 g/d. Synthesis predominately occurs in the liver, kidneys, and to a lesser extent in the pancreas. The remainder of the creatine available to the body is obtained through the diet at about 1 g/d for an omnivorous diet. 95% of the bodies creatine stores are found in the skeletal muscle and the remaining 5% is distributed in the brain, liver, kidney, and testes [1]. As creatine is predominately present in the diet from meats, vegetarians have lower resting creatine concentrations [2].

No. It’s not easy for everyone to get the recommended amount of protein in their diets through good eating habits alone. Others may not have clinically low testosterone, but still benefit from boosting their levels to improve their muscle building capacity. You can fix these common problems through muscle building supplements. These easy to take pills and powders can also help you boost your performance at the gym which will, in turn, spur your body’s muscle building and recovery response.