The real secret to being fit and healthy: High-intensity vs. low-intensity exercise

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I’m a big fan of hard work. It makes you faster, stronger, leaner, fitter, and healthier.

Countless articles have been written against “low and slow cardio,” saying that slow jogging and walking are useless. They praise the virtues of high-intensity training sessions as the only way to achieve great results. Not true.

I’ll be honest, the harder you can push yourself (without over training or getting injured), the better your results. That’s a fact. Running a mile burns more calories than walking a mile. But last year I had an epiphany. I learned that burning calories is just about the least important thing that exercise does. Sure, burning calories can help a bit if weight loss is your goal, but it pales in comparison to controlling caloric intake. When it comes to weight loss, it's food that really matters.

Harder, heavier and more intense lifting for longer periods is going to sculpt your body more than lighter lifting done for less time. The logic of it shines through. What’s more, exercise is a powerful tool for controlling appetite. Exercise works on the same neurochemical reward pathways in the brain as tasty foods. Junk food elicits a reward response in the brain; a rush of feel-good chemicals that make you want more. Higher intensity exercise works as a replacement for this because it works on the same reward pathways. It can make you crave junk food less, while eating junk food after a workout can actually blunt the reward sensations so it doesn’t elicit such a powerful feel-good response.

All that being said, a moderate, or even modest effort, is light years better than doing nothing. Yes, high intensity is awesome, but know that it’s for the few. So do what you can. There’s a lot of benefit to be had from moderate effort. A brisk walk three times a week enhances brain power and a regular walking regimen has a laundry list of health benefits. The fact is, walking is the most popular form of exercise on the planet. It’s awesome. Do it.

There is a major law of diminishing returns with exercise. The biggest benefits come from doing nothing to doing moderate intensity. Going from moderate to high intensity has significantly less benefits, by comparison’s sake.

Adherence is everything. If you hate high intensity then you won’t last. You’ve got to find something you can enjoy and live with. Perhaps even love doing. That is the real secret to being fit and healthy.

If over time, you find you’ve become comfortable with a moderate level of intensity there’s nothing wrong with pushing a little harder in increments. I’ve been taking that approach for almost 19 years and just ran my first marathon. Who knows what you’re capable of if you continue to advance with baby steps?

James S. Fell, MBA, is a certified strength and conditioning specialist in Calgary. He writes the syndicated column “In-Your-Face Fitness” for the Chicago Tribune and consults with clients on strategic planning for fitness and health. Get your free Metabolism Report here.