Given the importance of exercise to maintaining one's health and fitness levels, it's unfortunate that concerned individuals have to sort through a seemingly never-ending stream of misinformation, most of which is designed to sell ineffective equipment and unsafe supplements. If you're serious about building your muscles in a symmetrical and healthy way, you'll want to avoid the fraudulent muscle building substances, as well as any bizarre and flimsy equipment which focus solely on one part of the body. Even and safe muscle gain means a healthy diet with adequate caloric intake, short and intense workouts utilizing multiple muscle groups, and properly timed warmup and stretch periods.
Jumping right into a weight lifting workout after being sedentary for hours is a great way to injure oneself, but not particularly conducive to building muscle safely. Conventional wisdom used to hold that it was necessary to strength before lifting, though it has since been revealed that doing so can actually weaken muscles pre-lift. A better idea is to do some light jogging or stationary cycling for five minutes, in order to get your blood flowing and circulating throughout your muscle tissues. The current conventional wisdom is that it's best to stretch after a weight lifting workout, to prevent stiffness and release lactic acid buildup in the muscle tissues.
The internet is flush with questionable ads for "miracle" muscle growth supplements, most of which are completely useless, and some of which may be downright unhealthy. In terms of properly feeding your muscle growth, what you should be concentrating on is consuming an adequate number of calories based on your body weight and the intensity of your workouts, and getting an ample supply of protein. One good rule of thumb for weightlifters is to add 500 calories to the appropriate daily caloric intake for someone of their height and weight. You'll also want to be taking in roughly one gram of protein per pound of body weight on a daily basis. This can come from lean cuts of meat, fish or poultry, or from legumes, whole grains and low fat dairy products.
Lifting weights for hours, with lots of breaks in between sets, is an unnecessary waste of time which won't result in visible and even muscle growth, and which could actually lead to the injuries that can come with prolonged muscle fatigue. workouts should be no longer than 45 minutes in duration, doing between 12 and 20 sets per muscle group, and performing between six and 12 reps for each set. Each set should be markedly short (e.g. 40 to 70 seconds), and weight levels should be heavy enough to cause tangible exertion. In other words, keep your weight lifting sessions short and intense.
Compound exercises are exercises which engage multiple muscle groups simultaneously. These sorts of exercises are not only good for shortening and intensifying your workout, but are also good at evenly developing your muscles, as they force your muscles to maintain balance throughout the movements, resulting in improved symmetry of growth. Examples of compound exercises include squats, pull-ups, rows, presses and deadlifts. Another option is to alternate weight lifting routines between the upper body and lower body. While isolation exercises are effective, they also create the possibility of overdeveloping one muscle group at the expense of another.