For a long time there was a belief that doing a slow and controlled movement throughout the entire range of motion of an exercise was the best way to gain strength. Although that is definitely a much better way to go then trying to move heavy amounts of weight quickly by using momentum (and then throwing your back out), there is proof out there that it’s not the most efficient way to gain strength. There is a strong argument for Eccentric Training.
Eccentric Training works on the principle of doing “negative sets". A negative set is when you do the lifting part of the exercise (the concentric part) normally and then, during the lowering part of the exercise (the eccentric part), you go down really slowly. For example, during a barbell bicep curl, you would do a normal curl and then, instead of lowering the bar back down right away, you hold down the bar up and slowly lower it down over a period of 5-10 seconds. By doing this you are putting your biceps under great tension by forcing them to hold up the weight while also fighting gravity. This tears down your muscles more then normal lifting which will undoubtedly lead to greater muscle growth if you give your body time to recover.
When attempting Eccentric Training for the first time I suggest you lower the weight you would normally lift by anywhere from 30-50% because your muscles have probably never been under the type of stress you are about to put them through. If you put on the normal weight you would use for bench press and then try doing negative sets for the first time, I can almost guarantee that you will be unable to blast out the amount of repetitions you thought you were going to as well as potentially injure yourself if you push too hard. Even though you will need to lower the weight from what you normally would lift when first starting, just remember that it is proven that your strength gains are likely increase much quicker with Eccentric Training then with normal lifting. If you can keep that in your head and stay consistent with your workouts, there’s no doubt that you will be stronger and your muscle mass will increase tremendously.