Thanks, Joe. No question that recovery is a big piece, although not likely to be the only piece.
One conversation I often had with clients in our gait lab, was on the topic of scar tissue and the development of it in response to microtrauma. Which of course we all know is a double-edged sword.
I’d point out that when they’d cut themselves, very obviously a scab would develop during the healing process. Depending on the severity and quality of the tissue involved, as healing took place and the scab formed, what would be left at the end phase of that healing was a scar of some sort. The quality of that tissue/skin around the scar and the scar itself would be less elastic and obviously more fibrotic. Which would then mean in simple terms that it wouldn’t stretch quite as far or as easily as the tissue that hadn’t scabbed and thus scarred.
Then the conversation would turn to discussing this idea that the connective tissue inside of us that we CAN’T see as easily as that cut, also acts the same way. But because we can’t see it, we don’t think of it that way. Hence some of the reason for repetitive overuse injuries that many/most endurance athletes experience. Repeated microtrauma, less than optimal healing of that tissue before it’s again beat up on, and most importantly perhaps…the idea of compensation…and the very real issue of certain tissues being asked to do jobs they weren’t necessarily designed to do, which results in even more trauma to those tissues.
Now imagine the repetitive microtrauma to cardiac muscle from thousands of hours of mid to upper z2, with very little variation in those heartbeats. It’s not a pretty picture. I think, and this is my opinion…it’s less about the brief bouts of increased high intensity, and much more about the elevated steady-state hovering just below LT. That may result in some of that increased scarring from, again, repetitive microtrauma.
Naturally, all of that is happening over many years while we’re also aging, so connective tissue is at the same time, becoming less elastic and more fibrotic. It’s like a perfect storm as we age.
We see this inside and outside the body, but very often, it’s the less obvious results that aren’t or can’t be easily seen, that is the most important.
I do think this speaks in part to the extreme exercise hypothesis…and again, I don’t claim to be a laboratory researcher or to have spent umpteen hours going over whatever little research there actually is, but I’ve spent my entire adult life watching, listening, and observing these changes…in myself and in others I’ve worked with…
