Here are some very common errors made by beginners who seem clueless when it comes to the proper way to gain strength and muscle mass: More is not necessarily better when it comes to weight training in the gym. Your body needs time to recover when it's put under the stress of heavy lifting. Remember, when you perform weight training exercises you are literally tearing down muscle fibers. This means that in order for your muscles to grow the muscle fibers must undergo a healing process. If you fail to allow adequate recovery by giving at least 48 hours rest before hitting the same muscle group, you will likely fail to gain any appreciable muscle mass. Weight training provides the stimulus for growth but rest and proper nutrition is what's needed for the growth process to occur. Bottom line: Train each bodypart hard 30 to 60 minutes per session once per week and do cardio 20 to 30 minutes per session 2 to 3 days per week. In order to gain strength and muscle mass, you must lift progressively heavier weights over time. In other words, patience and discipline is required to make quality gains. Piling on a ridiculous amount of weight to gain strength and muscle mass faster is foolhardy at best and injurious at worst. Using bad form, bouncing the weight, and performing very short range of motion while straining to lift enormous amounts of weight is a recipe for disaster (read: injury). Bottom line: Utilize small incremental increases in weight from workout to workout while performing lifts. Failure in weight training is a good thing. This means that you are lifting a weight as many repetitions as possible until you're not able to perform one more rep. Soreness is the name of the game when lifting to failure. Just going through the motions is not going to cut the mustard. The weight lifted must be challenging enough that if your goal is to perform 10 reps, you will need to utilize intestinal fortitude in order to perform 11 reps. Each and every set needs to be this challenging in order to warrant a rest period. Be sure to limit any intensity technique such as drop sets, forces reps, rest-pause, etc. for the last set of an exercise in order to lessen the risk of overtraining. Bottom line: Make each and every set count by lifting a weight that causes muscle fatigue. If you're not training legs as intensely as arms, you are making a big mistake when it comes to gaining overall strength and muscle mass. Legs consist of the largest muscles within the body. Why would you want to avoid training such large muscles unless you'd prefer to have an imbalanced physique (i.e., humongous arms sidelined by toothpick legs!). If you want to get big, you need to squat, period. Compound movements such as squats, leg presses, hack squats, and lunges is what's needed to build a respectable physique. The bonus is training legs spurs more growth hormone release than training the upper body. Not only this, but your metabolic rate will increase significantly as well due to the increase of quad, hamstring and gluteal muscle mass. This means more calories will be burned while resting. Not a bad tradeoff. Bottom line: You must train legs if you want to gain appreciable strength and muscle mass.