When we're talking about gym training, the negative phase of a range of motion can be very positive. Let's start by defining negative, positive and static, which are the three phases a muscle can currently be in.
- Positive: Contracting the muscle, as in curling a dumbbell up.
- Static: Not moving, bracing yourself against the weight.
- Negative: Extending the muscle, as in lowering the dumbbell.
Now, the interesting thing is how these phases affect our strength differently, and also what effect you can expect, growthwise. (There's been different studies regarding this, with slightly different results, so I'll generalize a little - but the main point still holds true)
From what I've read, the major effect of positives is increase of brute strength. Volume, on the other hand, is where negatives come into play. This is supposed to be related to the difference of increased Motoric Unit effiency (in the muscle fibers) vs. when the muscle fibers are being torn apart most effectively, to put it bluntly.
1 Rep Max
Frankly, I'm not too sure any of this really matters in real life. Strength does, though!
Assume that you can do a 1 rep maximum, 1RM, of bicep curling a 100 lb barbell. That 1RM is 100% power output. Now for the interesting part - if you stop and hold is statically, you're stronger! And if you resist on the way down instead of just holding the weight still, you're even stronger If the positive 1RM was 100%, then Static is approx. 120% and Negative approx. 140%.
Why is this? The most credible explanation I've heard is that it's a defense mechanism of the body. I mean, if it was the other way around we'd be in trouble. We'd be able to pick up a huge rock and hold it above our heads, but once we're there we realize that we're too weak to hold it there. Ouch.
Seriously though, it's mostly common sense. It's like a safety buffer to ensure that we can't pick up something we can't handle, and in a worst-case scenario we always have the power to give the item a controlled descent back down.
This is the key to why negative training works! And this is also why you have to be both disciplined and experienced to do it safely. If you focus on making the most of the negatives, as in having a partner spot you and assist you in pressing the weight down to make it harder, you trick your body.
Simply put, you override the safety by filling the buffer with extra weight, thereby forcing your muscles to work harder than elsewise possible. The downside of this is exactly that - you override the safety limit! You must be very sure of what you're doing, and if you have previous joint problems in the area - forget it.
However, if you're able to successfully pull it off you can reap the rewards of increased muscle mass. Take note though, that this kind of training is not for everyone, nor can be done for weeks on end as it is very taxing on your body. Avoid overtraining - mix ordinary workouts with negatives ... And why not try alternating with other ways of raising intensity?
Soon there'll be an article on Partials on here, and I've found switching between partials and negatives as intensity-boosters to be a good way to keep the training challanging, productive and fun!