Using negative exercises, i.e., only lowering the weight after a spotter helps you lift the weight, can help you build muscle faster than "normal" lifting. It can be a nice change of pace in your fitness routine, too.
On this page we will cover the basics of how and why negative-only sets work and provide some tips on doing them yourself if you don't have a training partner.
As I mentioned above, "negatives" are the description we use to describe only the lowering of weight during strength training. This part of the lifting movement is known as the Eccentric part of the lift. Instead of using only your strength to push or pull the weight up, a training partner will assist you in that portion of the movement.
Let's use performing a bench press as an example. While you are on the bench, you and a partner will lift the loaded bar off your chest to the locked-out fully extended position above your chest. He/she will then let go of the bar. At this time, you will lower the bar to your chest in a controlled manner (shoot for 5 seconds to lower the bar). Do this until you can no longer sufficiently control the movement to that speed. Rest and repeat the set. Adjust the weight as needed. I would recommend starting with 3 sets and working up to 5 sets before adding weight.
Typically, you will be using weight that is approximately 20% heavier than when performing the exercise in both up and down directions. Why? We will cover that in a moment.
Even though we used bench press as an example, negative exercises can be used for curls, squats, dead lifts (although a second partner is helpful for some of these), chin ups and pull ups; almost any lift.
Negatives work, pretty simply, because you are using more weight in the lowering or eccentric movement vs. what you can lift in the concentric or raising movement. This extra weight allows for greater gains in a shorter time period.
The science behind it, if you are interested, is that the majority of the micro trauma (damage to the muscle fibers that I've discussed previously on this site)occurs during the eccentric phase of an exercise. This damage causes the muscles to adapt, which will build bigger muscles and help you to get stronger (the fibers repair themselves as you rest and sleep between workouts). The extra weight you use during negative-only sets causes more micro trauma and, therefor, greater muscle growth. For more information on negative sets, check out this link.
The usual and safest way to perform negatives is to have a spotter (or two on lower body exercises) help you lift the weight during the concentric movement and then monitor you during the eccentric lowering movement.
However, negative exercises can be done alone...to a certain extent. It helps to have a gym membership or a weight machine at home. One method is to lift the weight with both arms and lower the weight with one. Obviously, this would be difficult (not to mention unsafe) with a barbell. However, it can be done with a machine.
Another method that works well for pull-ups and chin-ups is to use a box or just jump up to where your chin is above the bar. Lower yourself in a controlled manner as described above.
Above all BE SAFE.
If you are looking for a new routine or trying to break through a training plateau, try negative sets. They may just be the jump-start you are looking for.