What is too much Cardio?

In last month’s newsletter, I talked about common mistakes people make in the gym. One of the mistakes I briefly mentioned was “too much cardio”. Several people asked exactly what is too much cardio. I gave a little explanation of what can happen with too much cardio, but not what IS too much cardio.

First, some definitions. Many people use the terms “cardiovascular exercise”, and “aerobic exercise” interchangeably. Although they do overlap to a great extent, they are not precisely the same thing. In very simple terms, cardiovascular exercise is exercise that improves the performance (health) of the heart and circulatory system. Aerobic exercise is exercise that improves ones aerobic capacity, or the ability of your body to process oxygen and deliver it to the muscles doing the work.

In a sense, Aerobic is a broader term than Cardiovascular. Aerobic exercise encompasses Cardio exercise. The heart is a big part of processing oxygen and delivering it to the muscles, but there is a great deal more that goes into it. In fact, after a certain amount of aerobic exercise, we stop making gains in our heart health. We maximize the efficiency of the heart, and gains in our aerobic capacity have to come from other sources. Once we reach this point, we are no longer gaining any heart health benefits from the added aerobic exercise. Someone who runs marathons is not any less likely to have a heart attack than is someone who runs three miles, three times a week.

So having established that, we really need to define WHY we are exercising aerobically to determine how much is too much. If you simply love to run “ultra-marathons” then there probably isn’t such a thing as “too much”. Aerobic fitness is your “thing”. It’s what you enjoy, and as such you should go for it. Just don’t fool yourself into thinking you’re doing it for your health.

In fact that much aerobic exercise is probably causing your body to tear down what it considers “unnecessary” bulk (muscle, bone, cartilage, tendons). Your body adapts to the stressors you put on it. If you continuously load your muscular-skeletal system to 10% of capacity (typical of most aerobic activity), then your body thinks the other 90% is wasted capacity. You may have a healthy heart, but your “quality of life” as you age might not be optimum.

What if your goal is to lose weight (fat). Well, aerobic exercise certainly does burn calories, but you have to run a long time to make up for even a small splurge in your diet. Two cookies might take an hour to burn off, and a donut might take upwards of two hours of cardio to burn off. It’s much easier to control your food intake in the first place, but if you simply love to eat, then endless hours of aerobic activity may be your only answer. Just remember, the more aerobic activity we do, the more muscle we lose, and it’s the muscle that makes us look “toned”. Like the example I used last month, compare the physique of a sprinter with that of a marathon runner. There’s a reason you’ll never see people like Richard Simmons without their shirt on!!!!

Now, if your goal is to look good, and be healthy, you need to make some compromises. Heart health is certainly VERY important. Everyone should get at least 30 minutes of aerobic exercise 3 times a week. Beyond that, my recommendation is to stick with the weights. In the long haul, resistance exercise will burn far more calories than aerobic exercise, and it will help you keep your precious muscle, even while dieting. We’ve all seen the anorexic girl that is nothing but skin and bones. Yes, she is thin, but no, she’s neither healthy nor attractive.

If you’re in a real hurry to lose as much weight as possible, or you just love to eat, and you’re already doing 3 or 4 sessions of resistance exercise every week, then you can certainly up the aerobic exercise beyond the above recommendation, but remember, if you’re trying to put on a little toned muscle, or you want to optimize your bodies “fat distribution patterns”, more aerobic exercise isn’t doing you any favors.

Remember, more isn’t always better. Pro bodybuilders are by no means “healthy”, but neither are marathon runners. Define your goals first, then choose the best path to get there. Or better yet, let a knowledgeable trainer help you choose the best path!