What Is Detraining?

EndurElite Chief Endurance Officer Matt Mosman discusses detraining/loss of fitness when you can't run, bike, swim, or do other endurance exercise.

Video Transcription:

Detraining: What It Is, What Causes It, How To Prevent It, And How Quick You Can Bounce Back

Oh, yeah, bababa, dadada. Good morning family of fast Matt Mosman, the Chief Endurance Officer over at EndurElite. I have a quick question/pop quiz for you today. And this is, what is worse than not being able to exercise? Is it one, having your fingernails pulled off. Two, getting a shot in the armpit. Three, getting kicked in the junk, not my favorite. Or four, detraining. If you answered number four, you win and you get the great prize of a high-five from me. Nice work. So we're gonna talk about detraining today. Basically, what it is, what can cause detraining, what happens physiologically to your body when detraining occurs, how you can prevent detraining, how fast you can expect a bounce back from detraining, and we'll throw in some research and a few stats for all you geeks out there as well.

What Is Detraining And Why Does It Happen To Endurance Athletes?

So in the simplest sense, detraining is a loss of fitness that occurs when you're not able to train, basically, due to getting injured, getting sick, having a scheduled kind of rest period or break period, decreasing the frequency and duration of your training. And there's a couple of other ones in there that basically causes detraining to occur.

What Physiological Changes Occur In The Body During Detraining?

Now, when detraining does occur, there's lots of physiological changes that occur in the body. And this is more specifically related to endurance training and not strength training, which we'll cover in a different video. But when you start to become detrained, mitochondrial density will start to decrease, capillary density will start to decrease, VO2 max will start to decrease, and even muscle fiber composition can start to decrease with detraining. And basically, all this means is decreases in endurance performance during this detraining period.

What Does The Research Say About Detraining In Runners?

Now, what about some of the stats and the research behind detraining? First, let's look at VO2 max. After stopping training for a while, VO2 max starts to decrease pretty quickly. It can decrease about 8% within 12 days after exercize stops, and then it can decrease about another 20% after 84 days of detraining. So VO2 max can really start to decrease pretty rapidly when detraining occurs. And this decrease in VO2 max is basically due to a decrease in maximal stroke volume and oxygen extraction or how much oxygen is getting to the muscles. And this is mostly due to the decrease in capillary density with detraining.

Now, submaximal exercise performance can suffer too and pretty rapidly. And this is due to a decrease in the mitochondrial density of the muscle fibers. So that's kind of some things that physiologically happen to your body when you're kind of going through this detraining process.

How Can Endurance Athletes Prevent Detraining?

Now, what's the best way to prevent detraining? Like, in some circumstances, you know, if you're taking a scheduled rest break for after a hard season of running or biking, you know, detraining is gonna occur, and that's fine. Your body needs to rest. But what if you get knocked out with, you know, an injury or an illness or something like that? In the case of an injury, if you can cross-train during your injury, you may decrease the amount of detraining that occurs. So that's one way to combat it.

The other way is just not to get hurt in the first place. And, you know, how are you gonna do this? Basically, the smartest idea here is to do periodized training with your endurance training, meaning scheduling hard workouts or hard weeks, but then also including easy days and recovery weeks. Like, my favorite thing to do to prevent, you know, detraining or, I guess, not to get hurt, is to have, you know, three harder weeks where, you know, frequency and intensity of exercise is going up or some combination of that. And then on the fourth week, kind of, take a down week where the frequency and duration or frequency duration intensity of my exercise goes down a little bit just so my body can recover. And I don't get hurt. I don't have to fall into detraining. So that's, kind of, the best ways to prevent detraining outside of, you know, taking a scheduled rest break for, like, a two, three weeks, which, you know, some detraining is gonna occur, but that's okay because you want your body to recover.

How Fast Does Endurance Fitness Come Back After Detraining?

Now, to end this video, how fast can you expect to bounce back from detraining? Say you get knocked out for, you know, one week, two weeks, three weeks, four weeks or more, how quickly can you expect to bounce back? And you know what? I don't really have the answer for that, unfortunately, and there's not a lot of research on that topic as well. It can differ so much from person to person depending on what level of fitness that person that is at when they get into a detraining mode. I think, obviously, the more fit a person is and then, kind of, figuring in there too how long they're out. The fitter person is probably going to bounce back a little bit quicker and get to previous fitter levels quicker than an individual who just started endurance exercise.

You know, there's one study out there that shows, you know, people who exercise for five weeks and then got knocked out for a week due to an illness, they lost about 50% of their training and adaptations from that previous five weeks of training, and then it took them about three to four weeks to get back up to that level of fitness that they experienced during the five weeks of training before the detraining occurred. So a little bit of insight there, but to sum it up, like, how quickly you can bounce back from detraining, there's way too many variables to consider, and it's going to differ from person to person.

So that is about all I have on detraining today my endurance friends. If you have a friend or buddy that's been knocked out of endurance training and wants to get back to it and want some information on detraining, please share this video with them. If you want other videos on endurance training, supplementation, and nutrition, subscribe to our EndurElite YouTube channel or head on over to the EndurElite blog at www.endurelite.com. Get social with us on Instagram and our EndurElite training and nutrition club page on Facebook. And until next time, my endurance friends, stay fueled, stay focused, stay fast, and stay informed.