For those of you who don’t know, I am currently a laboratory technician in the Physiology Lab at the Navy Experimental Diving Unit in Panama City. Some of my recent research has involved looking at the effects and timeline of detrainment, and I came across some interesting literature that thought I would share. Detrainment is defined as the partial or complete loss of training-induced anatomical, physiological, and performance adaptations as a result of reduction or cessation of training (Mujika and Padilla 2000).
Translation: detrainment is the process of “getting out of shape”, also known as “if you don’t use it, you lose it” syndrome.
Obviously, we want to combat detrainment because we don’t want to backslide. But as we all know, sometimes life gets in the way of us working out. So naturally, we have the following questions:
1) How fast will I detrain?
2) How can I keep this from happening?
There’s no easy answer to question #1. Studies have used a detrainment period ranging from two to sixteen weeks and begin reporting changes at seven to fifteen days. This seems to tell us that detrainment does not typically occur in less than two weeks, but unfortunately there are no known studies that have specifically researched the minimum time to detrainment.
Scienc-y stuff:
– In a study using rats, physical capacity and myocardial performance reverted to pre-trained conditions after only two weeks of detraining (Bocalini et al 2010).
– A study involving young basketball players showed no significant difference in explosive strength indicators after four, eight, twelve, or sixteen weeks of detrainment following a ten-week plyometric training program (Santos and Janeira 2011).
– The Dallas Bedrest and Training Study of 1966 (Saltin et al 1968) found that detrainment caused a significant decrease in the maximum O2 uptake (VO2max), cardiac output, heart rate, and stroke volume during exercise.
– A decrease in aerobic capacity in adults was seen after 15 days of bed rest (Stuart et al 2007).
– Greenleaf et al (1997) found that peak oxygen uptake decreased by day seven of the study.
Now, on to question #2. Obviously, daily exercise is going to keep detrainment from happening (Lee et al 2009, Lee et al 2007). But one study actually found that stretching also combats detrainment (Kasahara et al 2010)! So if you can’t get a workout in for a few days at a time, try doing some stretches to keep from losing all that hard work you put in at the gym! Try yoga at home or check out these stretch-at-your-desk videos from Mayo clinic to help maintain your level of fitness even when you can’t actively work out.
erinsimmonsfitness 
Hey Erin, Been thinking about this topic a bit recently, so it’s a touch serendipitous that you’d bring it up. So I thought I’d reply and share my thoughts (instead of me wearing out the mouse by liking all your stuff on facebook :))
I’m no elite athlete, but I’ve found in my experience that I seem to have a kind of baseline fitness that makes it easier for me to regain what I once had compared to other people I know eg. I ran for exercise when I was at university, and earlier this year when I started regularly running again I wasn’t too far off my times from back then – which is almost 10 years ago (wow writing that makes me feel old… :() My own theory was that I ran around a lot as a kid and played every sport I could at school so I probably won’t as affected by inactivity as others might be because of my history. That’s despite only being a fairly sporadic exerciser between then and now. I play kinda-competitive basketball once a week, but sometimes I won’t do anything else over the week if there’s bad weather or I’m lazy, yet I don’t seem to lose a significant amount of fitness. One advantage I have though is I can’t put on weight – I’ll always be skinny 🙂 So that’s one factor my friends have to deal with that I don’t.
I guess that’s the other question though: how much is typically lost through detraining? Will I run 20% slower if I sit on the couch for 3 months over Christmas? Or will it only be 5%? I imagine stuff like gym strength might be lost more quickly, because that doesn’t seem as natural an activity as running, so I would theorise that the body might retain the ability to run a bit better than the ability to bench press. I know the amount of push ups I can do has probably halved since I’ve stopped doing them regularly – so from 20-30 to 10-15…yes, getting a bit stronger is a New Years resolution…haha
Of course one reason for my experiences could be that I’ve never really ‘peaked’ eg. I’ve never trained really hard for something for 3mths, because I imagine that it would be easier to notice detraining effects if you had really pushed hard to get to your peak. The advantages of being a non-elite athlete I guess – I still can’t quite slam dunk a basketball, just like I couldn’t quite do it 10 years ago 🙂
Hope you gained at least something from my ramblings! Sounds like interesting research you get to do.
All the best,
Glenn.
Glenn,
The first thing I think you have to realize us that you’re not comparing yourself to other people, you’re comparing yourself to, well, yourself! So yes, I agree that you do probably have a baseline of your fitness. i.e. I will probably always be able to do my approach for javelin or go run a mile. However, after a certain amount of time off I may not be able to throw my average distance for javelin or run an 8 minute mile. Remember, many of these studies used bed rest as the stressor to measure detainment so for them, complete loss of fitness is a very real possibility. In daily life, chances are it will be only a partial loss. As for the percent backslide, I would say that it depends on the person and, like you pointed out, prior history of exercise. Though if you’re really pushing yourself, I would think that it would be much easier to lose ground if you take time off. I didn’t see any studies addressing that aspect of it, though, so I’ll keep an eye out!
Thanks for the feedback 🙂
2) Good to know that stretching can help! There are lots of time when work and other competing priorities get in the way of training. Now I just need to set aside the time for it!
1) Is a very tricky question and is based on how you would interpret the definition “the partial or complete loss of training-induced anatomical, physiological, and performance adaptations as a result of reduction or cessation of training”. Partial is an easier question, I think. Complete loss would be very difficult to determine in lifelong athletes and, my supposition is, no amount of detraining would result in a complete loss for those individuals.
(Disclaimer: My Ph.D. is in biomedical engineering so I’m relatively clever but, since I haven’t studied these topics I’ll comment on my own anecdotal observations 🙂 )
For an individual who was a competitive athlete beginning in grade school and extending through college or even high school it seems that, anatomically, their body has been shaped by their activities. A gymnasts or swimmers shoulders provide good examples. They will, for many years after (if not always), appear more developed than non swimmers (especially women). Having been around athletics for most of my life I’ve grown pretty adept at spotting athletes and knowing what sports they played, even if they haven’t competed in years, just by looking at them and how they move. Similarly, it seems like someone who’s done intense weight training for extended periods of time will maintain more muscle mass than an average individual even if they discontinue training.
The other observation regarding physiology is that resting heart rates for athletes who’ve reached a certain level of cardiovascular condition at some point in their life is typically lower even if they haven’t trained intensely in years.
Now with regard to PARTIAL loss, I recall during wrestling seasons that if I took just two days off in a row (i.e.) the weekend, I was sucking wind on monday!! 🙂
Man, now I need to go for a run…….
Rob,
In regards to stretching, if you click the link in my article you’ll see stretches you can actually do at work! So when you get a break you can fit them in 🙂
In regards to your other question, see what I wrote to Glenn above concerning complete vs partial loss. I agree that you can often tell the sport someone does even if it’s been years since competition. This is because each sport requires the body to adapt in certain ways and some of those changes end up being relatively permanent. This includes heart rate as well, so even if an athlete is not training intensely, they are more likely to have a lower heart rate because their body has been conditioned that way in the past.
Hope all this makes sense, thanks for the comments!