^ Burd, Nicholas A.; Yang, Yifan; Moore, Daniel R.; Tang, Jason E.; Tarnopolsky, Mark A.; Phillips, Stuart M. (2012). "Greater stimulation of myofibrillar protein synthesis with ingestion of whey protein isolate v. Micellar casein at rest and after resistance exercise in elderly men". British Journal of Nutrition. 108 (6): 958–62. doi:10.1017/S0007114511006271. PMID 22289570.
Although muscle stimulation occurs in the gym (or home gym) when lifting weights, muscle growth occurs afterward during rest periods. Without adequate rest and sleep (6 to 8 hours), muscles do not have an opportunity to recover and grow. Additionally, many athletes find that a daytime nap further increases their body's ability to recover from training and build muscles. Some bodybuilders add a massage at the end of each workout to their routine as a method of recovering.
Intensive weight training causes micro-tears to the muscles being trained; this is generally known as microtrauma. These micro-tears in the muscle contribute to the soreness felt after exercise, called delayed onset muscle soreness (DOMS). It is the repair of these micro-traumas that results in muscle growth. Normally, this soreness becomes most apparent a day or two after a workout. However, as muscles become adapted to the exercises, soreness tends to decrease.
In the modern bodybuilding industry, the term "professional" generally means a bodybuilder who has won qualifying competitions as an amateur and has earned a "pro card" from their respective organization. Professionals earn the right to compete in competitions that include monetary prizes. A pro card also prohibits the athlete from competing in federations other than the one from which they have received the pro card. Depending on the level of success, these bodybuilders may receive monetary compensation from sponsors, much like athletes in other sports.
Starting May 15th and running through Sept. 1st, teens ages 15-18 can work out TOTALLY FREE. No catches, no commitments. Come in and use tons of cardio and strength equipment on your own, or sign up for our free fitness training classes. Plus, enter for the chance to win a $5,000 scholarship and other prizes! Visit any Planet Fitness on or after May 15th to sign up for your free summer membership. Under 18 must have a parent or guardian present at sign up. More information available here.