I had an interesting observation while I was working out. It may not be new to you guys at all though.
I found that if you lift the weight very quickly, the weight gets light. On the same note, if the weight goes up a slowly, the muscle seems to be more tense.
In the cable machine in our gym, you can either set use the a light setting or a heavy setting wherein you lift half the weight with twice the distance and speed of the light setting, in effect yielding the same tension (similar to gear ratios). However, even if I set the weights at their equivalents, they feel very different. It seems to me that you can use momentum in the heavy setting to assist you in the lift whereas momentum is harder to get in the lighter setting.
I'm thinking that it has something to do with gravitiational acceleration. If you accelerate the weight faster than gravity does (9.8 m/s/s), momentum takes over and the weight gets lighter. If you accelerate it less, momentum doesn't take over and the weight stays heavy. This could explain why the heavy setting gets more momentum. The weight accelerates faster, allowing momentum to take over.
Hence, if one wants constant tension in a muscle, one has to accelerate the weight more slowly than gravity does. I guess that means lifting weights more slowly can stress muscles more than when lifting weights as fast as possible because of the constant tension, although it doesn't mean that you'll get stronger. Maybe it's good from a hypertrophy standpoint. Heck, it sounds like Mike Mentzer was onto something.
I guess that means I'll be using the light setting each time I use the cable machine so that I can lift as fast as I can without momentum taking over.
What do you guys think about this?