What Exercise Can and Can’t Do

It’s the time for New Year’s resolutions again, which for many people includes losing weight. And a lot of people think the best way to do that is by exercising more.

Except – they’re wrong.

The role of exercise in weight loss has been a question for a long time, but it seems that they’re not related much at all. According to Herman Pontzer, who has studied metabolism and authored the book Burn, someone who exercises a lot burns about the same number of calories as someone who’s sedentary.

That seems counter-intuitive, but to me, it’s also another reminder of why focusing on an end goal like weight loss isn’t the best option. So with that in mind, I thought I’d look a little more at why exercise doesn’t help with weight loss, as well as some of the many real benefits of exercise.

Exercise doesn’t help much with weight loss

We’ve all heard the “calories in, calories out” idea about weight management, and even though it’s more complicated than that, it’s hard to get away from that idea. That’s why it’s so easy to think that if you just burn more calories by exercising, you’ll lose weight.

This doesn’t work for a couple of reasons. One is that you may feel entitled to eat more after exercising, which negates any calories you may have burned. You also have to exercise a lot to burn very many calories.

But the other reason is what Pontzer calls the “constrained total energy model”. As he explained in a Washington Post article, the idea is that if someone is very active, their body can actually slow or shut down other biological operations that would normally burn up calories, such as digestion. With those operations shut down, the calories saved are burned by activity instead – with the net result of burning the same number of calories whether active or inactive.

The reverse is also true, that if you stop being quite as active, it doesn’t automatically mean you’ll gain weight. I found this out for myself recently because I sprained my ankle in late October, and I had to stop going for walks for quite a while. I was doing physical therapy exercises, but they were pretty light. Despite that, I didn’t gain weight.

But that’s not to say exercise isn’t important. It offers a lot of other benefits.

What exercise can really do

Exercise can do many good things, which makes it unfortunate that many people lump it in with weight loss – and then when they don’t lose weight, they give up on exercise. But there are so many reasons to keep up with exercise regardless of weight goals. Here are some:

• Improved cardiovascular and lung health: Exercising improves circulation and strengthens your heart and lungs, which in turn reduces risk of cardiovascular disease. I’ve noticed this first-hand, how not going for long walks for a couple of months, and walking more slowly, meant that I now get winded more easily as I get back into walking. It’s a good reminder to keep at it.

• Decreased risk of falls: Balance-related exercises are very important as you age because they can dramatically reduce your chances of falling. Even something as simple as standing on one leg for 30 seconds can help, especially if you do a few sets a few times a week. (Note that if you’re walking and a tripping hazard is buried by leaves or snow, balance exercises will probably not save you, or at least they didn’t help me. So also be careful where you’re walking, especially in winter when ice can be treacherous.)

• Improved bone health: Weight-bearing exercises are important not only for building muscle but also improving bone health. This is even more important for older people who are more likely to lose bone density, and it will reduce the risk of broken bones if you do fall. For example, an 86-year-old neighbor recently fell down the last few stairs to her basement (always possible if you’re carrying too much and can’t see the stairs), and while she was bruised and sore, she didn’t break anything. She attributes that to the fact that she goes for 3-mile walks several times a week as well as going to the gym for weight exercises.

• Reduced anxiety and depression: Exercise isn’t only good for your physical health – it also helps with mental health, including reducing anxiety and depression. This is partly because exercise releases endorphins that help you feel good, and it also gives you something to focus on, something where you can see measurable improvement as you gain strength and endurance.

• Better sleep: If you have trouble sleeping, exercise can help. Even moderate exercise can help you fall asleep faster and stay asleep. Better sleep also improves your mental health, ability to focus, and how much energy you have.

Focus on how you feel, not your weight

Exercising for weight loss will backfire, so it’s best to take weight out of the equation. Instead of numbers on the scale, focus on how you feel during and after exercise. Odds are, you’ll see changes in how much you can lift, how easily (or not) you get winded, how much better you sleep, as well as feeling less anxious and better able to do day-to-day activities. You may also feel improved confidence.

These are just some of the ways exercise can help. So, whether or not you’re trying to lose weight, adding more activity to your life will have many other benefits that make it well worth doing.