Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "

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Kaatsu bench press: more pecs with less weight

If you reduce the blood supply to your arms with bands and then do bench presses with minimal weights, you can build up considerable strength and muscle mass. Researchers at the University of Tokyo did experiments with 10 young men.

In Japan Kaatsu is well known. Sports shops in Japan sell Kaatsu belts and Kaatsu suits [see photo] and Kaatsu training is all the rage in sports centres and wellness institutes. [] Should you be thinking of starting training at Kubira: the first Kaatsu lesson is free. []

Kaatsu is basically training done by restricting the blood supply to the muscles. The researchers are not quite sure how it works, but low-intensity Kaatsu training results in a big anabolic stimulus. Walk at a brisk pace with Kaatsu and youíll develop stronger leg muscles, whereas if you do the same without restricting the blood supply you wonít develop any muscle mass at all. And the same applies for strength training with minimal weights.

So far scientists have studied the effects of Kaatsu training on muscle groups that can be restricted using bands, like the calf and upper leg muscles. But what happens if subjectsí arm muscles are bound, but they then do bench presses? Will only their triceps get bigger and stronger? Or do the pecs benefit from the Kaatsu effect as well, even though you canít bind them? Thatís the question these researchers set out to answer.

They got 5 men aged between 23 and 38 to do bench presses for 2 weeks with bands around their arm muscles. A similar group did normal training. The subjects trained 6 days a week and did 2 bench press sessions every day: one in the morning and one in the afternoon. Each session the men did 3 sets at 30 percent of the weight at which

they could just manage 1 rep. They did 30 reps in the first set, followed by 2 sets of 15 reps.

The figures below show the results from scans. They record how the muscle mass in the triceps brachii and the pectoralis major increased by 8 and 16 percent respectively in the Kaatsu group [black circles]. The increase in muscle mass in the control group was nil.

The weight at which the test subjects could just manage 1 bench press increased by 6 percent in the Kaatsu group. In the control group there was a 2 percent decrease.

The growth hormone level rose in the Kaatsu group.

Apparently the Kaatsu effect spreads from the restricted muscle group to a group that is not bound, the researchers conclude. How this happens they donít know. Reading between the lines itís clear that they donít believe that this is caused by the increase in growth hormone levels. The mechanism behind Kaatsu training remains a mystery.

Clin Physiol Funct Imaging. 2010 Sep 1;30(5):338-43.

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