As long as I’ve been around weight training, the conventional wisdom has always been that you should rotate muscle groups on various days. If you work legs and back on Monday, you should rest legs and back on Tuesday, but you’re free to work them again on Wednesday. My high school football coach said that your muscles need the extra day to flush out the impurities (lactic acid, etc.) from the first workout, and to develop new muscle. Some people have gone so far as to say that working out the same muscles on succeeding days will actually retard muscle growth.
This makes absolutely no sense to me. Taken to an extreme, it seems to imply that the best way to improve muscle growth would be to work out on Monday, and then sleep all day Tuesday. And from an evolutionary standpoint, a human that needs a day of rest before growing muscle would seem to be much less likely to survive. A quicker recovery time would seem likely to improve the chances of finding food and avoiding becoming food. And from personal experience, professional athletes that spend all day, every day running around and exercising don’t seem to be lacking in muscle mass.
All due respect to my high school football coach, but this seems bogus to me. Does anyone have the Straight Dope?
A lot of bodybuilders come very close to that. They alternate between sleeping and working out. 12+ hours of sleep/day. And as you say, they alternate muscles groups. However total rest is not ideal for muscle development because some movement is needed to move fluids through the muscles and to help the fibres align properly. Work out on Monday and light exercise and massage Tuesday is ideal, and that’s what most of the pros do.
That’s flawed for two reasons.
Firstly no one has said that you need to rest before growing muscle. Most people grow muscle from working, not pumping iron, and they do so quite well by working 5 days a week. It may not be the best way to do it but it works.
Secondly novel muscle growth is associated with novel stress. Novel stress that you can survive but that is constant for months would have been almost unheard of in primitive societies. If a river changed course and you needed to swim it for some reason then you might need novel muscles in the upper body. However you wouldn’t need to swim it every day. You might only swim it once a week. You’d develop the new muscle but you would be resting in between. Same if a new food source became available. If Og discovers that a fruit is edible if picked green then he might start climbing trees and might need new muscle. However he wouldn’t need to climb trees every day.
I don’t see why. A person in recovery is just as effective as a person who isn’t barring tears etc, and the body heals those as fast as possible. It can’t just ‘evolve’ instantaneous repair and even if it could it probably wouldn’t because these things are always a trade off. Faster repair would probably also equal more mistakes including cancers.
Professional athletes don’t spend all day every day running around when they are developing muscle mass. They do it when they are maintaining muscle mass.
Lactic acid is not the problem. Your body converts this back to glucose in a matter of hours, at the most. The problem is that when you stress muscles, you actually tear them slightly, and they then rebuild stronger than ever. This is known as eustress (good stress). However, if you start to tear them down again before they have had a chance to rebuild, they will never get stronger. This is known as distress (bad stress). Stress is good for the body as long as the body is able to adapt. As a result of this adaption, the body gets stronger. If you are not able to adapt, either by too quick a return to the stress or too much stress (think “strain”), the body does not get stronger, but, in fact, you will be in distress.