Lot of information I don't agree with in this thread.
Strength and muscle size, though they overlap are two different things. When I was younger I was incredibly strong and had mega endurance. I rode 200 miles on a bicycle once in 10 hours and 50 minutes and I could leg press over 900 pounds in the gym. I was a lot stronger than I looked. Typically I trained 450 to 600 miles a week which was severely over training and as a result I had incredible endurance but no ability to sprint at the end of the race. I would often lead the race for most of the way and get passed by several people in the last few seconds. Fast forward more than 40 years and I hardly train at all yet my muscles look much bigger than they did back then. I wish I knew then what I know now. I could have combined the best of all three: speed, strength and endurance and won a hell of a lot of races. I also didn't know much about dieting back then and was a vegetarian. But that's another story.
Though I am pretty strong today there are a lot of people that go to the gym that can lift more than I do but don't look half as muscular. If you want to gain muscle mass you got to train like a sprinter. Lift like mad with little or no rest between sets. To train for strength take a nice long rest between sets and spend a long time in the gym. I go for maximum muscle damage in the shortest time possible. My workouts seldom exceed more than 20 minutes two times a week but I train furiously as if my life depended on it. (I also do a one hour cycling class twice a week but I take it easy for most of the class and even on the parts that are supposed to be high intensity training I take it easy and only sprint hard for the last 10 seconds but I give it everything I got!)
Rest is even more important than the workout. Your muscles don't grow while you are working out. They only grow while you are resting. Your body also only produces growth hormone while you are resting but you must rest your entire body including your digestive system. Studies have shown that you can increase your rate of growth hormone production more than 15 times by doing intermittent fasting. I normally fast for 16 hours a day and do all of my eating in an 8 hour window.
Most important of all is diet. A raw egg has everything a chicken needs to grow from the size of a tiny speck into a chick in just a few short weeks. Till I discovered raw organ meats, raw eggs were the best thing I knew of for growing muscles. Bodybuilding is 75 to 90 percent diet. Power lifting a little less but still important.
