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From the time we’re born until somewhere around our 30’s, our muscles grow larger and stronger. I’ve written about it before… it’s our whole “growth” phase, when our bodies are pretty forgiving and can still radiate health even if we don’t exercise. And then we turn 40 (or so) and suddenly things start to change. Our default fades from “growth” to “deterioration”, and without exercise, our muscles begin to get smaller and weaker.  It’s called age-related sarcopenia.

All of that’s well-known and accepted. Problem is, too many people are misinterpreting it. It’s become all too common to jump to the conclusion that we will inevitably lose our muscle mass and our strength with age. We’re all wasting away, apparently, so just accept it. No, people. Just no.



This picture is from one of my most favorite studies of this decade.  It was significant back when it was published in ‘The Physician and Sportsmedicine‘ journal in 2011 because at the time, it seemed every other related study was measuring natural muscle loss on the general population, but this one contradicted all that by showing that age-related sarcopenia IS NOT INEVITABLE. Its effects can be held at bay with exercise, as evidenced by this remarkable MRI comparison photo. Just look at those big beautiful meaty quadriceps on the 70-yr old athlete. And how about his bone diameter! Compare that to sedentary man’s thin bone, minuscule muscle, and even more adipose tissue density within the muscle mass itself… and, well I just want to get up and do some squats right now.

So here’s the hard truth about our aging muscles:

The amount of muscle you’ll lose as you age is due to your activity levels. As long as you’re an otherwise healthy adult, it’s your choices that will decide which of these MRI scans more closely resembles you. Let’s stop accepting that muscle wasting is our natural aging process, because at least up until the very end stage, it isn’t. Our modern culture’s sedentary way of life is more to blame for muscle loss, not aging.

But hey, there’s a bright light here, even if you’re currently not exercising. Because even if you’ve made some bad choices up till now, your body is remarkably adaptable. It WILL work with you and respond favorably to new exercise habits!

Now, I’m not saying for older folks it’s as EASY to build and maintain muscle as it is for younger people. Youth have their “growth default mode” advantage. Think of it like training at high altitude and then having the advantage at a sea level race, while us older folks don’t have the sea level advantage. It can be done, we just have to work harder, consistently, and be much smarter about our advanced-years training.

Okay, all that said, let’s move on to a new (but related) topic.

Get a load of this:

This comes from a study published by the American College of Sports Medicine, and it’s showing the number of functional motor units in the arm muscles of nine young runners (the ‘Y’) with an average age of 27, nine old runners (the “O”) with an average age of 70, and nine lifelong masters runners (the “MR”) with an average age of 70. Take note these people are RUNNERS. They’re using their legs to perform their activity, not their arms.  As you can see, the older folks have significantly less motor units in their arm muscles (so, less muscle mass and less strength) than the young runners… proof of the age-related sarcopenia process at play here.

What this shows is that just the act of exercising doesn’t give us some sort of “whole body neuroprotection.” Exercise only preserves the muscles you’re using. I know, this isn’t mind-blowing or anything and seems common sense. But yet culturally, we sort of know this and ignore it. Runners continue to just run, cyclists just bike, and the walkers seem to think they’ve got fitness covered too. GANG, YOU DON’T. You have to push, pull, and carry heavy things if you want to maintain a strong and fit bod long into your post-retirement years.



I probably could have summed this whole thing up in 5 words:

Use it or lose it.

It’s that simple. Though let’s be real, it’s nowhere near easy.

So here’s today’s tip from me. Go commit that quadriceps comparison picture up above to memory. I did that almost a decade ago and I still think about that picture every now and then; for me it’s the most powerful single photo motivator I’ve ever seen. On lazy days, I pull up that image and BAM. I’m up and going. May it work the same sort of motivation magic on you, too.

Keep the conversation going with comments below. Then go exercise!


Trainer Stef