When reading this please have an open mind. Whenever evaluating long held beliefs about scientific questions it helps to understand that much of what we are told is simply scientists guessing. They make guesses (hypotheses), do some preliminary testing and then tell everyone about them. I don’t have a problem with this. What else can they do? The problem is that these guesses often prove false, and the scientists won’t admit that they were wrong. Or people have believed these guesses so long that they can’t accept that they are wrong.
Take margarine, for example. This was created as a healthier butter replacement. We now know that margarine is about the most unhealthy thing you can eat. I wonder how many people died prematurely because of this guess.
This post is me summing up “Body by Science” by Doug McGuff and John Little. If you want more details, get the book. I’m not going to try to go through it in order. If something seems wrong or doesn’t make sense it is likely a deficiency in my explanation or understanding.
First off, they make a distinction between health and fitness. For them being fit means you are maximizing your physical capacity. Being healthy means the absence of disease and a balance between the body tearing itself down and building itself up. The idea with exercise then is to maximize fitness without damaging health. Sounds like a plan to me.
In the next section of the book they explain metabolism and exercise. It’s pretty technical so I won’t summarize. I’ll quote a bit that I think is helpful – “Over several decades, all sorts of positive health benefits became associated with this specific metabolic adaptation (related to aerobic exercise – my comment). Soon, it became a foregone conclusion that aerobic conditioning was cardiovascular conditioning and that the two were interchangeable. What never seemed to have been pointed out is that the heart and blood vessels support the entire functioning of the cell, not just the mitochondria.” They then go on to say that strength training is the best way to train the cardiovascular system since it stimulates all the components of metabolism. The point is that doing aerobic exercise conditions only a part of our cardiovascular system, while strength training trains all of our cardiovascular system. Why do aerobic exercise, unless of course you really enjoy it?
McGuff and Little quote two studies that were done showing that a few minutes of intense exercise is as good as or better than several hours of “cardio” exercise. Check out the links below
http://edition.cnn.com/2005/HEALTH/06/06/sprint.training/
http://www.telegraph.co.uk/health/healthnews/7429028/Short-blasts-of-exercise-as-good-as-hours-of-training-scientists-find.html
Another issue with doing low intensity repetitive exercise is body wear and tear. Remember, the idea with exercise is to maximize fitness while improving, or at least not damaging, health. Doing exercises that impact your joints over and over are clearly out (who thought high impact aerobics was a good idea?). I forget the percent of runners who are injured every year, but I believe it’s over half.
As an aside, studies have been done showing that marathon runners seem to have more heart problems than the average person. I wonder if this is from the stress that running puts on your heart?
http://www.paleonu.com/panu-weblog/2009/11/1/cardio-causes-heart-disease.html
Back to the book. Putting this together, then what we want to do is intensely stimulate our muscles while minimizing impact on our joints. What “Body by Science” recommends is one set each of a few exercises that hit all the major muscle groups in your body. The exercises are to be done slowly, say 20 seconds per rep, for roughly 90 seconds. The weight should be such that you are at failure after the set. You then wait for your muscles to rebuild, which varies for everyone, but roughly a week. They then go into advice on various routines and exercises you can do and what equipment to use.
There are many wonderful things about this method of exercise but maybe the best is people who want to be fit get their lives back. People no longer need to be on the trail or treadmill an hour every day. Fifteen minutes a week is enough. Plus for men, we get to look buff instead of gaunt.
Buy the book.