Thursday, July 29, 2021

Benefits of Aerobic Exercise

They May Be Closer Than You Think

Walking has obviously become insanely popular, but for some folks, questions remain like how many steps should I target each day, and how much overall health benefit can I really expect from walking?

On a recent walk, and yes it was hot outside
The first thing to understand is that walking is not sitting, so it automatically moves you out of the sedentary and into the active category. Everything else is details.

This simple framing permits your brain to classify it accurately and motivate you to get active enough to make some kind of difference without overthinking it — and that’s huge. Still, some people look past this simple and effective way to think about it, mainly those who need numbers and goals to motivate them and those who need confirmation from third parties — in the form of studies — to validate easily observed empirical changes in their own lives. 

I’m no doctor or exercise physiologist, but I have substantial experience with steady-state aerobic exercise — 40+ years ago I was a running fanatic (6 days and 40 miles a week), and later I became a biker, and then added walking about 10 years ago. I’ve also read a bit about the clinical side of it, but primarily my own experience has taught me many things, and always confirmed what I’ve read about the clinical benefits.

Here’s what I’ve learned. 

All steady-state aerobic exercises — “aerobic” means “with oxygen”, meaning your muscles are getting the blood supply and oxygen they need to do work for a long time — work the same basic way, with two distinct phases:  warm-up and equilibrium. 

During warm up you start from resting pulse rate and respirations and body temperature and metabolic rate, and then as you start moving you increase all of those gradually for around 10-15 minutes (shorter if you’re in excellent shape, longer if in poor shape) before you hit equilibrium. where all of those same measurements stabilize so that your body (and especially your cardiovascular system) becomes like a fully-warmed-up car engine that is operating at peak temperature and efficiency. 

Because your body responds to demands upon it, during equilibrium there are lots of good things that happen to your cardiovascular system, your blood, your cells, your muscles and capillaries, even your brain and emotions, etc. 

Maximizing the time spent in this equilibrium state is they key to gaining the most benefits. 

This is the only important point to memorize about any type of aerobic exercise. It’s all about time spent in that state, because this is when — along with the recovery period over the next 24-48 hours — the big benefits occur. Over time, say 6-12 weeks, and depending somewhat on intensity of the exercise: 

  1. Your body creates more red blood cells to carry more oxygen to your muscles through new capillaries, greatly improving circulation. 
  2. Your lung capacity increases, your heart becomes stronger, and these changes to lead to feeling better all the time because your heart and lungs are working better. 
  3. Your blood chemistry improves in every way, from more HDL to lower LDL and triglycerides.
  4. Your body produces endorphins, improving mood and emotional energy for several hours. 
  5. All parts of the body benefit from all of these changes:  skin, nails, eyes, internal organs, hands and feet, are all served better and more efficiently with more oxygen to your cells from improved circulation. 
  6. You feel more alive and have more energy and better mental focus. 
  7. Sleep quality improves, which then helps you handle tomorrow better. Rinse and repeat. 

The point here is that this list is long and impressive, and every single person who has ever done this kind of exercise for any length of time can confirm all of it. 

Dr James Meschino does a great job of explaining this.

Here’s the Cleveland Clinic on the benefits of aerobic exercise and how to realize them — they say as little as 30 minutes a week will at least help a little bit, and I have no reason to doubt it.

Research on activity levels correlating with cardiovascular health and weight loss stretches back decades and is not exactly revolutionary or hidden away. The life insurance business depends on such research to set rates. However, that’s another topic for another day.

So: anything that gets you up off the couch and moving your legs in any way at all, for at least 10 minutes, is good for any person at any age. Do as much as you can. Training for triathalons and marathons is obviously an entirely different discussion. The rest is details.