If you recall about 6 months ago I looked at the question how long does it take to lose muscle? In that article I set off to see just how long one could take a break from lifting before they would start to see actual muscle loss. As a quick recap the answer varies depending on many factors such as genetics, age, nutrition and fitness level. The more advanced of a weight lifter you are the quicker you are likely to see some form of muscle loss. Research showed more recreational lifters could take as long as 12 weeks to show loss while competitive athletes took between 2-4 weeks. While strength loss usually appears sooner than muscle loss, it’s mostly neural. The main point of that article was to show you that if you need to take a week or two of for whatever reason, you didn’t need to worry about losing muscle in that time.
Today what I would like to do is do a bit of a follow-up to that article. Sure if you deload or get sick or go on vacation and miss a week or two you probably don’t need to worry about muscle loss, but what about the times when you sustain an injury and can’t help but avoid training for a longer period of time? When you do lose that muscle it sure is a pity to start all over again, or do you? You may have heard that while it seems like muscle goes away quckly but rebuilding muscle mass is fast too, and it’s true, but why?
It’s often called muscle memory, but is it fact or broscience? Research by Bruusgaard et al. (2010) (1) looked at how the effects of previous strength training can be sustained even after long periods of inactivity. They used in vivo imaging to study live myonuclei and they observed that new myonuclei are added before any significant increase in size during overload. They noticed that old and newly acquired nuclei are retained even during severe atrophy. Basically what they found was myonuclei increases when you train, but when you detrain the number of myonuclei remains the same. So why is this good? Well more myonuclei means more mRNA and in turn more muscle-protein synthesis. This is likely why it takes much less time to regain lost muscle than it does to gain it the first time.
Even better support for taking a couple of weeks off was looked at in a recent study by Ogasawara et al. (2013) (2) In this study researches looked at how resistance training creates muscle anabolism rapidly in the early stages and becomes progressively slower over time. Nothing new here, however, what their research showed was after a 12 day period of detraining one becomes more sensitive to anabolic signaling including muscle-protein synthesis. The detraining period effectively restored p70S6K and rpS6, while when training was continued they only continued to decline. In a sense the detraining period allows you to grow muscle at a faster rate than if you were to continue to work without taking time off.
Research by Radi et al. (2004) (3) falls pretty well in line with both of the above studies. During this study subjects trained for 90 days and followed it up with 90 days of detraining. What they found was no difference between myonuclei at the end of both phases, meaning they were not lost even after 90 days of detraining. Satellite cell content increased by 19% at 30 days and 31% at 90 days. Compared to pre-training values the number of satellite cells remained significantly elevated up to 60 days but not at 90 days of detraining. So the contribution of satellite cells appear to peak early in a detraining phase with the maximum number of satellite cells per muscle fiber being achieved after 10 days of detraining and returning to pre-training levels after 90 days. More evidence that short detraining periods can be of even more benefit than avoiding overtraining alone.
This is all great support for including periods of deloading into your training routine, of course finding the optimal period of time to train and detrain is important for maximum muscle growth. You can’t detrain every couple of weeks just because it restores anabolic signaling, so the question becomes how long to train before detraining. Of course it’s different for everyone but I highly recommend checking out my method of purposefully overreaching and then going through a detraining period for an optimal method of muscle-building if that’s your goal. I feel this new research only helps the case for this type of plan. Not only do you have the benefit of forcing your body to adapt to the extreme loads and having the snap back effect during your deload where you actualize your gains, but when you come back you’ll do so being more sensitive to anabolic signaling. Talk about a win-win situation.
It can be hard to do sometimes but if you want the greatest results it’s smart to utilize deloading/detraining periods when it’s needed to ramp up the body’s anabolic signaling again and if you sustain an injury you can relax and take the time to allow it to heal. You’ll be able to regain your strength and muscle much more quickly than you did the first time. While regaining the lost muscle will be easy, working through an injury could lead to even worse problems and further setbacks. Be smart and listen to your body.