Note: This article was the MASS Research Review cover story for September 2022. If you want more content like this, subscribe to MASS.
I assume that if you’re reading Stronger By Science, training is an important part of your life. However, most people either have to take some time off of training, or choose to take some time away from training, at some point. Even if you never miss a training session for any reason whatsoever, you’ll occasionally need to take time away from training a particular body part due to injury.
So, what should you reasonably expect when you stop training for a while? How long does it take to experience a noticeable decrease in strength and muscularity? What can you do to mitigate losses in strength and muscle mass? And how should you go about returning to training?
This article will attempt to answer all of these questions, and probably a few more.
Impacts of Training Cessation On Performance
To start things off, let’s first explore the impact of training cessation (not training for a period of time) on performance.
A 2013 meta-analysis by Bosquet and colleagues summarized this literature nicely (1). This meta-analysis is nearly a decade old, but it included 103 studies, making it one of the largest meta-analyses conducted in our field. Importantly, the impact of additional studies gets smaller and smaller as meta-analyses get larger. If a meta-analysis only includes five studies, then accounting for an additional three studies may have a pretty large impact on its effect estimates. However, if a meta-analysis has 100 studies, the addition of 10 new studies is unlikely to have a meaningful impact on its effect estimates. In other words, this meta-analysis isn’t hot off the presses, but it’s also far from being outdated.
The researchers began by finding all of the studies that met three inclusion criteria:
- The study needed to include a training intervention, followed by a period of training cessation.
- The study needed to measure muscular performance following the training intervention and following the period of training cessation.
- The study needed to report all of the necessary information for calculating standardized effect sizes.
The researchers were interested in the effects of training cessation on maximal strength, maximal power, and strength endurance. Maximal strength was assessed via 1-5RM strength or maximal force on a dynamometer in the included studies. Maximal power was assessed via jump height, sprint tests, peak torque during high-speed dynamometry, or power output during submaximal lifting tasks. Strength endurance was assessed via ≥ 6RM strength, time to exhaustion during isometric dynamometry, or total work completed during an isokinetic fatigue test.
Impacts of training cessation on maximal strength
The researchers found that maximal strength was mostly unaffected (pooled effect sizes were trivial; g < 0.2) following up to 28 days of training cessation (Figure 1). Strength losses accelerated after 28 days of training cessation, however.
The researchers performed sub-analyses to identify predictors of the rate of strength losses. They found that upper and lower body strength were lost at similar rates, and that males and females lost strength at similar rates. However, they did find that older adults (≥65 year old) lost nearly twice as much strength and younger adults (<65 years old). The pooled effect size for older adults was g = 0.76 (95% CI = 0.62-0.90), which was more than twice as large as the pooled effect size for younger adults: g = 0.31 (95% CI = 0.21-0.40).
Impacts of training cessation on maximal power
Losses in power were smaller than losses in maximal strength (Figure 2), especially for longer periods of training cessation (113-224 days of training cessation). However, I suspect that simply reflects differences in trainability for strength vs. power. In other words, you could easily add 100 pounds to your squat following a period of training, and lose 100 pounds off your squat following a period of detraining (which might represent a 20-40% swing in total squat strength). However, you might only add three inches to your vertical jump following a period of jump training, and lose three inches from your vertical jump following a period of detraining (which might represent a 10-20% swing in jump height). In other words, “losing all of your gains” for measures of maximal power generally corresponds to smaller standardized effect sizes than “losing all of your gains” for measures of maximal strength.
As with the strength findings, males and females experienced similar reductions in maximal power following training cessation. Furthermore, losses in upper and lower body power occurred at similar rates. However, once again, older adults experienced far larger losses in maximal power output than younger adults: g = 0.46 (95% CI = 0.21-0.72) for older adults, versus g = 0.18 (95% CI = 0.10-0.26) for younger adults.
Impacts of training cessation on strength endurance
Strength endurance was negatively impacted by training cessation sooner to a greater degree than maximal strength or power (Figure 3). I’ll explore the potential reasons for the larger decreases in strength endurance later in this article.
Once again, losses in strength endurance occurred at a similar rate for upper body and lower body tests of strength endurance, and for both males and females. Furthermore, losses in strength endurance were considerably larger for older adults than younger adults: g = 0.85 (95%CI = 0.57-1.12) for older adults, versus g = 0.48 (95%CI = 0.26-0.70) for younger adults.
My primary takeaway from this meta-analysis (1) is that younger adults can “get away with” about a month out of the gym before their performance suffers very much. Sure, you’ll probably get pretty sore after your first few workouts back in the gym, and it may take a couple of sessions to knock the rust off and get back in a good groove with your training, but you should expect to maintain your performance pretty well. However, older adults take a bigger hit when they spend some time away from the gym. Unfortunately, Bosquet and colleagues didn’t report the actual time course of strength, power, and strength endurance losses independently in younger vs. older adults (just pooled magnitude estimates across all studies), but I suspect that losses in performance start accelerating following about two weeks of detraining in older adults.
Impacts of training cessation on muscle mass
The Bosquet meta-analysis didn’t investigate the impact of training cessation on muscle mass, and I was unable to find a similar meta-analysis summarizing the research investigating the impact of training cessation on muscle mass (though a meta-analysis investigating the impact of training cessation on muscle mass in older adults appears to be in the works; 2).
When you delve into the literature, however, I think separate patterns emerge for young versus older adults. Here are four illustrative studies in young adults:
- In a study by Staron and colleagues (3), college-aged women completed 20 weeks of lower body training, followed by 30-32 weeks of detraining. Following the detraining phase, lean mass (assessed via skinfolds), mid-thigh circumference, gluteal circumference, and type I and type IIa fiber cross-sectional area of the vastus lateralis didn’t significantly change (4).
- In a study by Psilander and colleagues (5), subjects in their mid-20s completed 10 weeks of quad training, followed by 20 weeks of detraining. Following the detraining phase, muscle thickness decreased toward baseline values, but fiber cross-sectional area didn’t significantly change (Figure 4).
- In a study by Bjørnsen and colleagues (reviewed in MASS; 6), subjects completed two 5-day blocks of intense quad training, separated by 10 days of rest. Fiber cross-sectional area was assessed for up to 10 days following the final training session, while rectus femoris cross-sectional area and vastus lateralis thickness were assessed for up to 10 days following the final training session. Fiber cross-sectional area continued increasing throughout the post-training period, while rectus femoris and vastus lateralis size regressed slightly (though the change wasn’t significant).
- In a study by Seaborne and colleagues (also reviewed in MASS; 7), subjects completed seven weeks of quad training, followed by seven weeks of detraining. Leg lean mass (assessed via DEXA) increased during the seven weeks of training, and regressed toward baseline values following the seven weeks of detraining.
Overall, it appears that measures of whole-muscle mass, thickness, or cross-sectional area tend to decline following detraining periods. The Staron study (3) presents an exception to this rule, but it assessed whole-muscle size using pretty inexact measures. The other three studies found, collectively, that measures of whole-muscle size decrease non-significantly within 20 days of training cessation, and decrease back near baseline values following 7-20 weeks of training cessation. However, it also appears that gains in fiber cross-sectional area are preserved quite well following a detraining period (Figure 4).
I’ll admit that interpreting these findings is pretty challenging. You could argue that the decreases in measures of whole muscle size are more reflective of what’s “truly” going on – muscle atrophy is occurring following training cessation. After all, a muscle biopsy only provides you with insight into a relatively small sample of the total muscle, so changes in whole-muscle thickness, cross-sectional area, or lower-body lean mass are more informative. Alternately, you could argue that preservation of muscle fiber cross-sectional area is more reflective of what’s “truly” going on – you don’t actually lose much muscle following training cessation. After all, we primarily care about the contractile elements of muscle tissue, right? Assessments of whole-muscle mass, thickness, or cross-sectional area may pick up on decreases in extracellular water or connective tissue content with training cessation, leading to the erroneous conclusion that muscles are shrinking. In actuality, the contractile elements of muscle tissue might be well-maintained, even following a period of training cessation.
I personally think the truth is somewhere in the middle. I do think most people overestimate the rate at which they lose muscle with training cessation. Due to decreases in muscle edema, decreases in muscle glycogen content, and potentially even decreases in muscle blood flow (since less oxygen would be needed to fuel muscle remodeling when the stimulus for elevated muscle remodeling is removed), muscles might start looking “flat” following a week of training cessation, but this perceived decrease in muscle size is unlikely to reflect a true loss of muscle tissue. However, I also strongly believe that a significant loss of contractile and structural protein occurs within 20-32 weeks of training cessation – I don’t think that the relative lack of change in fiber cross-sectional area tells the full story. For a deeper dive into the topic of assessing muscle hypertrophy (and, by extension, muscle atrophy), I’d strongly recommend this paper from Haun and colleagues (8). The short version is that assessing muscle hypertrophy and atrophy is a lot more complicated than most people realize.
On a practical level, I’d suggest that losses in muscle mass likely run roughly in parallel with losses in strength assessed via relatively simple exercises. In other words, if you’re out of the gym for two months, losses in squat 1RM probably aren’t a great indication of losses in lower body muscle mass. Squats have a significant skill component, so losses in squat strength might simply indicate that your motor patterns are a bit rusty. However, if your maximal leg press strength (or even better, your maximal knee extension strength) is down, those strength reductions probably reflect “true” losses in muscle mass. So, until more (and better) data is published, my assumption is that the pattern of strength losses observed in the Bosquet meta-analysis (1) are informative about the losses in muscle mass that occur – you probably maintain your muscle pretty well for about a month out of the gym, but losses in muscle mass accelerate after longer periods of training cessation.
Moving over to older adults, the research is much more straightforward. Losses in both whole-muscle size (9) and fiber cross-sectional area (10) occur with detraining. Once again, it’s hard to granularly assess the time course of muscle losses that occur with training cessation (since individual studies don’t assess muscle cross-sectional area or take biopsies every week during the detraining period). However, I suspect that the strength findings from the Bosquet meta-analysis are informative once again – older adults probably lose muscle about twice as fast as younger adults during a period of training cessation.
Why are losses in strength endurance larger than losses in maximal strength?
At first, it may seem unintuitive that strength endurance is lost at a faster rate than maximal strength during a period of training cessation. After all, we expect our motor patterns to be a bit rusty after time away from the gym, so it makes sense that maximal strength performance should take a hit. Higher rep training is a bit less dependent on your motor patterns being perfectly sharp, so it might seem like strength endurance should be better maintained than maximal strength. However, this finding should make a bit more sense when we zoom out and examine the metabolic de-adaptations that occur with training cessation.
As I’ve written about previously, resistance training can be a surprisingly metabolically taxing task – at least in short bursts. The energy expenditure of an entire training session may not be tremendously high compared to other forms of exercise (primarily due to the breaks you need to take between sets; 11), but the metabolic cost of each set can be quite high over a very short period of time.
To illustrate, Escamilla and colleagues (building upon prior work by Brown and colleagues; 12, 13) found that a set of 8 deadlifts with 175kg (385lb) burns about 25kcal. To put that in perspective, running 400m also burns about 25kcal for an average-sized person. If you’ve ever done an all-out 400m sprint, you know the metabolic cost of rapidly expending 25kcal; even if you’re well-trained for the task, you’ll be huffing and puffing like a freight train after a 400m sprint. If you’re not particularly well-trained for the task, you might vomit and need to lie down on the track for 5-10 minutes just to catch your breath. So, if you’ve ever wondered why you’re absolutely wrecked after completing a true 8-20RM set of squats or deadlifts (especially if you’re quite strong), that’s why – you may be expending energy at a rate that’s comparable to an Olympic-level 400m runner, but I doubt you’ve done nearly as much aerobic or anaerobic conditioning work as an Olympic-level 400m runner.
The raw energy expenditure values for smaller exercises (say, biceps curls) are considerably lower than the values observed for squats or deadlifts, simply because less muscle mass is being used, and less total work is being performed. However, the same principle applies in miniature – local energy usage of the active muscles is going to be extraordinarily high (relatively speaking), and performance is going to be limited by the ability of the active muscle tissue to produce enough energy. Once the muscle fibers can no longer produce enough ATP to maintain the required rate of cross-bridge cycling, or for the timely clearance of metabolites, you’ll fail to produce enough force to complete another rep.
So, strength endurance performance is affected by the same factors as maximal strength performance – your muscles’ ability to produce force and your nervous system’s ability to adequately coordinate muscle contraction – while additionally being constrained by your muscles’ ability to create enough energy throughout the set. Thus, if training cessation brings about a decrease in aerobic and anaerobic fitness (due to decreases in blood volume and hematocrit, decreases in mitochondrial density, decreases in concentrations of key enzymes involved in aerobic and anaerobic metabolism, decreases in capillary density, etc.), we should expect to see a larger decrease in strength endurance performance than maximal strength performance.
That’s precisely what we see. Most of the research investigating changes in aerobic and anaerobic performance focuses on team sport and endurance athletes going through a period of training cessation (14, 15), but I see no reason to anticipate that resistance trainees wouldn’t also experience a decrease in aerobic and anaerobic fitness. Resistance training brings about many of the same adaptations as more traditional anaerobic conditioning training (16), albeit to a lesser extent (17).
Since training cessation results in both strength loss and decreases in aerobic and anaerobic conditioning, and since strength endurance is (roughly speaking) the product of maximal strength and local aerobic and anaerobic conditioning, it’s unsurprising that strength endurance losses exceed losses in maximal strength during a period of training cessation (Figure 5).
As one final note, astute readers may have noticed that the actual pooled effect size estimates for reductions in maximal strength and strength endurance didn’t differ to a huge extent in the Bosquet meta-analysis: 0.76 vs. 0.85 for older adults, and 0.31 vs. 0.48 for younger adults. However, those pooled effect estimates are based on the effect sizes reported in studies examining periods of training cessation of different lengths. So, if there were a lot of studies examining the effects of relatively short-term training cessation on strength endurance, and a larger number of longer-term studies examining the effects of training cessation on maximal strength, you could easily wind up with comparable pooled effect estimates, despite also observing larger decreases in strength endurance performance over every discrete time scale. Based on the data reported in Figures 1 and 3, I strongly suspect that we’re observing this type of dynamic at play.
After you take some time away from training, you’ll probably find that you can regain most (or all) of the muscle and strength you’d lost in a pretty short period of time. The “bros” have referred to this phenomenon as “muscle memory” for decades, and the term seems to be catching on in the scientific literature.
When I first started paying attention to the sciency side of the fitness industry in approximately 2010, I remember being told that muscle memory was mostly an illusion. At the time, the “orthodox” position was that a significant portion of lost strength was rapidly regained as lifters honed motor patterns that had grown rusty during their period of detraining (leading to the mistaken impression that muscle was also being rapidly rebuilt), but that lost muscle had to be rebuilt gradually. In other words, the muscles themselves didn’t actually “remember” how large they’d previously been, or possess any cellular mechanisms to facilitate the regrowth of lost muscle tissue. So, if it took you two years to build 5kg of muscle, and then you lost all of that muscle during a year away from the gym, it would take you an additional two years to rebuild the lost muscle.
Then, in 2013, a study by Egner and colleagues caused a pretty huge paradigm shift (18). In that study, mice were given supraphysiological doses of testosterone for 14 days, leading to considerable hypertrophy. After testosterone treatment was removed, the muscle fibers decreased in size over the next three weeks. However, following a period of overload exercise (achieved via synergist ablation), the mice rebuilt all of the muscle they’d lost during the “detraining” period. Furthermore, another cohort of mice that hadn’t been given testosterone and hadn’t previously experienced hypertrophy also underwent the same period of overload exercise. This second group of mice achieved less hypertrophy during the overload period than the group of mice that was merely rebuilding muscle (Figure 6).
This study both suggested that “muscle memory” was a real phenomenon – muscle can be rebuilt faster than it can be built initially – and it posited that a compelling pair of cellular mechanisms could explain this phenomenon: myonuclear permanence and myonuclear domain theory. It’s probably beyond the scope of this article to really get into the nitty-gritty of myonuclei regulation and the extent to which myonuclei regulate muscle size, but there’s a previous article on the topic that should bring you up to speed (19). In short, myonuclei are the “control centers” of muscle fibers. Unlike most human cells (which have a single nucleus), muscle fibers have multiple nuclei. As muscle fibers grow, they accrue more myonuclei. It appears that each myonucleus can “oversee” a finite volume of muscle fiber contents (its “myonuclear domain”). When myonuclei are stretched to their limits – the myonuclear domains are as large as each nucleus can manage – muscle growth becomes a slow process. However, when myonuclei are overseeing smaller myonuclear domains, they can rapidly ramp up gene transcription (leading to increased gene translation and increased protein synthesis), leading to considerably quicker muscle growth (or regrowth). Crucially, when muscle is lost during a period of detraining, it appears that the vast majority of those myonuclei stick around. So, when you get back under the bar, your myonuclei are overseeing smaller myonuclear domains, thus allowing you to quickly regain lost muscle tissue (32).
Research in the intervening years suggests that this myonuclei-mediated mechanism may be a factor contributing to muscle memory, but it’s not the only relevant mechanism (again, I’d recommend my previous article on the topic; 19). Notably, a 2018 study by Seaborne and colleagues found that epigenetic regulation of gene expression might also contribute to the phenomenon of muscle memory (7). A recent study hinted at another potential mechanism – resensitization of cellular signaling pathways associated with muscle growth following a period of training cessation (20). I wouldn’t be surprised if there are additional mechanisms waiting to be discovered. But for our purposes here, the precise mechanisms of muscle memory aren’t terribly important – just know that that concept of muscle memory is solid and scientifically supported (33).
Unfortunately, the precise time course of muscle memory-assisted strength re-gain and muscle regrowth isn’t well-understood. In other words, if you take six months out of the gym, and lose an amount of muscle and strength that it previously took you three years to build, we don’t know precisely how long it’ll take to rebuild all of the muscle and strength you lost. The primary reason for this gap in our knowledge is that research examining both detraining and retraining generally isn’t adequately designed to assess the time course of strength and hypertrophy adaptations during the retraining period. In other words, a study may involve 12 weeks of training, 24 weeks of detraining, and 12 weeks of retraining, with assessments of strength and muscularity at the start of the study, at the end of the training period, at the end of the detraining period, and at the end of the retraining period. The subjects may have more muscle and strength at the end of the retraining period than they had at the end of the initial training period, but we don’t know precisely how long it took for their strength and muscularity during the retraining period to equal their strength and muscularity at the end of the initial training period. The reason for this gap in our knowledge is that most studies don’t assess strength and hypertrophy on a weekly basis throughout the retraining period.
However, research does suggest that the period of time required to regain lost muscle and strength is shorter than the period of training cessation. For example, in the Seaborne study, subjects trained for seven weeks, detrained for seven weeks, and retrained for seven weeks (7). Subjects were substantially stronger and more muscular at the end of the retraining period than at the end of the initial training period, suggesting that it took less than seven weeks for the subjects to regain their lost muscle mass and strength. Similarly, a study by Henwood and Taffe involved 24 weeks of training, 24 weeks of detraining, and 12 weeks of retraining. The 12-week retraining period was sufficient to regain all of the strength lost during the detraining period (21). The aforementioned study by Psilander and colleagues had similar results (5). Subjects trained for 10 weeks, detrained for 20 weeks, and retrained for 5 weeks. The subjects were slightly stronger and slightly more muscular at the end of the retraining period than at the end of the initial training period. Similarly, a study by Ogasawara and colleagues compared two groups completing six months of bench press training (22). One group trained for six months straight, while the other group followed a pattern of training for six weeks, taking three weeks off, training for six more weeks, taking three weeks off, etc. Over the six-month training period, gains in bench press 1RM strength, pec cross-sectional area, and triceps cross-sectional area were similar in both groups. This suggests that the muscle and strength lost during the three-week detraining periods were rapidly rebuilt, allowing for each six-week training period to result in additional gains in strength and muscularity.
The Ogasawara study is particularly interesting because bench press 1RM was assessed every three weeks, thus allowing us to observe changes in strength over shorter time windows. After both three-week detraining periods, subjects experienced small decreases in 1RM strength. However, following three weeks of retraining, the subjects were (slightly) stronger than they’d been at the end of their prior six-week block of training. Unfortunately, pec and triceps thicknesses weren’t assessed as frequently as strength, thus giving us less insight into the precise time course of muscle re-growth.
A study by Taaffe and Marcus also assessed strength on a more frequent basis – every two weeks – over the course of a detraining and retraining study (10). Subjects trained for 24 weeks, detrained for 12 weeks, and retrained for 8 weeks. During the retraining period, it took the subjects six weeks to regain all of the strength they’d lost during the 12-week detraining period.
Until more granular data are published, I believe the research suggests that the period of time it takes to regain lost muscle and strength is approximately half as long as the preceding period of training cessation, with a rough confidence interval spanning from 1/3rd the length of the period of training cessation, up to 2/3rds the length of the period of training cessation. In other words, if you took three months (12 weeks) off of training, I suspect you’d be able to regain your lost muscle and strength within 4-8 weeks, with 6 weeks being my current best guess.
Mitigating the negative effects of training cessation
If you need to take time off from training, you’ll likely wonder what steps you can take to mitigate the negative impact of a period of training cessation. Is there anything you can do to minimize losses of strength and muscle mass?
Let me start by noting that training cessation exists on a spectrum. The Bosquet meta-analysis summarized the effects of “normal” training cessation (1) – subjects lifted weights for a period of time, and then stopped lifting weights while returning to their normal lifestyle. However, a period of training cessation might also be caused by a serious injury or illness, requiring bed rest or the complete immobilization of a limb. Research suggests that under these conditions, you don’t maintain muscle and strength reasonably well for up to a month. Instead, you hemorrhage muscle and strength at a pretty astounding rate – strength losses can exceed 1% per day, and muscle losses can be around half a percent per day (23). Conversely, you may put your training on pause because you start a very physically demanding job. For example, maybe you start work for a moving company, so you don’t want your back to be sore from deadlifting because you’re going to be moving couches and refrigerators up and down stairs for eight hours per day. Sure, this might be a period of “training cessation” while you adapt to the demands of your new job, but I strongly suspect that you’d maintain your muscle and strength quite well for quite a long time in this circumstance.
With that in mind, if the option is available to you, my best recommendation would be to not actually stop training entirely. It takes way less effort to maintain muscle and strength than to build additional muscle and strength – it doesn’t take a very large stimulus to maintain your muscle and strength for a very, very long time. For example, in a 2011 study by Bickel and colleagues young lifters (20-35 years old) and older lifters (60-75 years old) initially underwent a 16-week training phase, followed by a 32-week (8-month) phase of training with reduced volume, or complete detraining (24). A third of the lifters stopped training entirely, a third of the lifters reduced their volume by 2/3rds, and a third of the lifters reduced their volume by 8/9ths. The researchers found that the younger lifters could maintain their muscle and strength over 8 months by maintaining just 1/9th of their original training volume (Figure 10), and older lifters (60-75 years old) could maintain strength with just 1/3rd of their original training volume, though they may still experience some reduction in muscle mass.
A more recent study by Antunes had similar findings (25). Older women (> 60 years old) completed a 20-week training intervention involving three sets per week of multiple exercises. Following the 20-week training program, a third of the women continued training with three sets per exercise, a third of the women continued training with two sets per exercise, and a third of the women continued training with just one set per exercise for an additional 8 weeks. The group that cut their training volume down to one set per exercise was able to maintain (or slightly increase) their strength and lean soft tissue mass over the 8-week period of training with reduced volume.
So, even if you’re away from the gym, losses in muscle and strength should be minimal if you can just find a way to still do some resistance exercise. Something as simple as 2-3 sets of push-ups, pull-ups, split squats, and back raises or hip thrusts once or twice per week should be sufficient to maintain the vast majority of your muscle and strength for a long, long time. There are some muscle groups that are more challenging to train without any gym equipment (the spinal erectors and hamstrings, in particular), but if you can just carve out 30-45 minutes per week for a bit of bodyweight training, you can really put the brakes on muscle and strength losses when you’re away from the gym.
I realize that “still do a bit of training, actually” really stretches the definition of “training cessation,” but it actually meshes well with some of the reasons why someone might go through a period of full training cessation. Lack of time and lack of enjoyment are cited as two of the primary reasons people don’t participate in dedicated exercise (26). So, you might be staring down a period of training cessation because changes in your schedule severely curtail your leisure time (for example, maybe you recently became a new parent, you started a new job with a significantly longer commute, or you’re enrolling in night classes while still working a 9-to-5 job), or if you might be stepping away from serious training for a period of time because the grind of intense workouts is making your feel burnt out. In one of those situations, shorter-duration, less taxing workouts may allow you to reap the benefits of a period of training cessation, without losing the muscle and strength you’d worked so hard to build.
If you either can’t do any form of resistance training, or you simply don’t want to do any resistance training during a period of training cessation, then my primary recommendation would be to simply maintain a protein intake of approximately 1.3-1.4g of protein per kg of lean mass (27), and to avoid large caloric deficits or surpluses (28). We’re frequently asked if considerably higher protein intakes or any specific supplements can help with the maintenance of muscle mass during a period of training cessation, but I’m unaware of any research suggesting that extreme protein intakes or legal supplements can have a significant impact on muscle retention in the absence of a resistance training stimulus.
Returning to training
Assuming you don’t intend to give up on resistance training entirely, you’ll need to consider how you plan to return to training following a period of training cessation. Dr. Zourdos has already made a great video about returning to training after a layoff, and Dr. Jason Eure has written a great article about the risks of returning to training. I’d recommend those two pieces of content for in-depth examinations of this topic. However, I feel that this article about training cessation would be incomplete without at least touching on the subject of returning to training.
When you return to training, you’re probably going to be focused on regaining lost muscle and strength so that you can start making further gains. However, I think you should also be concerned with minimizing injury risk (since some evidence suggests that injury rates are elevated when athletes re-introduce intense training after an offseason; 29, 30) and re-conditioning your muscles. With that in mind, I think it makes sense to start with a rough, somewhat conservative plan for your return to serious training.
For your first week back under the bar, I’d recommend including all of the exercises you plan to perform in your “normal” training (once you’ve regained your strength), with the same set and rep volume you intend to use. However, for this first week of training, use very light weights. Using about 1/3rd as much weight as you used before your period of training cessation should provide you with a good starting point.
For example, maybe your typical upper body workout previously included 3 sets of 10 bench press with 225lb, overhead press with 150lb, pull-downs with 120lb, barbell rows with 150lb, curls with 30lb, and triceps extensions with 45lb. Eventually, you’d like to get back to those numbers.
For your first week of training, jump straight back to 3 sets of 10 reps for all of those exercises, but use 75lb for bench, 50lb for overhead press, 40lb for pull-downs, 50lb for barbell rows, 10lb for curls, and 15lb for triceps extensions.
This may seem like hilariously easy training, even after a prolonged period of training cessation, but it actually serves a purpose. Research has shown that training with just 10% of maximal force for a single session can dramatically attenuate soreness, post-training strength reductions, and blood markers of muscle damage when training ramps back up (31). As you’re returning to training, excessive soreness could derail early attempts to rebuild the habit and lifestyle of training consistently. If you planned to do upper body training on Tuesday and Friday, and lower body training on Wednesday and Saturday during your first week back in the gym, you may be demotivated to stick to that schedule if you can’t raise your arms over your head on Friday, and you can’t walk comfortably on Saturday due to the effects of your Tuesday and Wednesday workouts. By taking the first week of training really easy, you should significantly reduce the risk of excessively severe DOMS derailing your path back toward consistent training.
For your second week of training, your aim should be to feel out weights that are challenging but not hard for all of your exercises. Some prior experience with autoregulation using reps in reserve-based ratings of perceived exertion (RIR-RPE) helps considerably. For your first set of each exercise, you should aim to have at least 5 reps in reserve, and you should aim to still have at least 3-4 reps in reserve for your final set of each exercise. This is just your second week back in the gym, and your first week of somewhat challenging training – you’re still reconditioning your muscles and re-acclimating to training, so you should be disciplined and resist the urge to test your limits and, in doing so, potentially increase your injury risk. Don’t be afraid to reduce your working weight if you selected a weight that’s a bit too heavy for your first set, and don’t be afraid to increase your working weight if you selected a load that’s a bit too light for your first set. Also, don’t be surprised if your performance changes from set to set in an unpredictable manner. If your muscles are severely deconditioned, it’s entirely possible that your first set of an exercise will leave you with 6 reps in reserve, and your second or third set will leave you with just 1-2 reps in reserve due to the rapid onset of fatigue. Conversely, it’s also entirely possible that your second, third, or fourth set of an exercise will be noticeably easier than your first set, as your nervous system de-rusts old motor patterns in real-time. So, during this week of training, it’s very important to pay close attention to the feedback your body is giving you so that you can select appropriate training weights.
From there, you should be able to sketch out a rough plan for regaining the rest of your lost strength and muscle mass, following this process:
- Add up the number of weeks you spent away from the gym. Divide by two. That’s roughly how long it should take to return to your prior levels of performance.
- Treating the week of training you just completed as week 1 (i.e., ignore the introductory week that involved training with ⅓ of your prior training weights), subtract your pre-training cessation training weights from your week 1 post-training cessation training weights.
- Divide your current strength deficit by the number of weeks it should take to regain your lost strength, minus 1. That will tell you how much your training weights should increase week-by-week.
- Repeat for all of your lifts. That should provide you with a rough blueprint for returning to training.
Here’s an illustration, which should help clarify this process:
First, let’s assume that your period of training cessation was 12 weeks. 12 ÷ 2 = 6. So, it should take about 6 weeks to regain your lost strength.
Next, let’s assume that you were previously squatting 405lb for 5 sets of 5 reps. During your first introductory week of training, you performed 5 sets of 5 reps with 135lb. We’re ignoring that week. During your first “real” week of training, you found that 255lb was a challenging but comfortable working weight for 5 sets of 5 reps. So, your current working weight is 405 – 255 = 150lb lower than your prior working weight.
Next, to calculate weekly load increases, divide your current strength deficit (150lb) by the number of weeks it should take to regain strength, minus 1 (6 – 1 = 5). So, 150 ÷ 5 = 30lb. So, your training loads for the squat should increase by 30lb per week. Repeat this process with each lift.
Of course, doing a lot of math by hand is no fun, so I’ve made a spreadsheet that will do all of these calculations for you. You can access it here to make a copy in Google Sheets, or here to download it for use with some other spreadsheet program.
As a general note, these return-to-training guidelines should be interpreted as a rough directional indicator, rather than a fixed roadmap that you can’t stray from. Monitor your level of exertion as you retrain. If reps in reserve start trending up (i.e., you had 3 reps in reserve on your final set during your first week of retraining, but you feel like you have 5+ reps in reserve on your final set during your third week of retraining, in spite of absolute loads increasing), you should be able to progress training loads a bit faster. Conversely, if you start consistently having just 0-1 reps in reserve, you may need to progress training loads a bit slower. Once you can’t increase loads week-to-week anymore, that indicates that your retraining period is over, and it’s time to shift back to “normal” training. For most folks, this should roughly coincide with the point at which your current training loads equal the training loads you were able to handle prior to your period of training cessation. However, some people will likely fall a bit short of their prior training loads (especially if they lost a significant amount of weight during their period of training cessation), and some people will be able to slightly exceed their prior training weights before linear progress slows to a halt.
If your period of training cessation was less than a month long, just treat it like it was an extended deload. Easing back into training shouldn’t need to be a big, multi-week process. In your first week back under the bar, just bump your training loads down by about 20% (relative to the loads you used in your last completed week of training). From there, you should be able to resume “normal” training without a hitch.
If your period of training cessation was more than a year long, I’d probably recommend treating yourself like an untrained lifter, and embarking on any training program employing a standard linear progression (adding 5-10lbs per week to lower body exercises, and 2.5-5lbs per week to upper body exercises).
The main thing I wouldn’t recommend is progressing in load as quickly as possible with very low training volumes, with the intention of increasing training volumes only after your strength has mostly recovered. For example, if you just worked up to a single hard set of 3-8 reps for each lift once or twice per week, your strength performance would rapidly increase. However, you’d also be leaving your muscles and tendons relatively deconditioned. I won’t pretend like I have solid references to back this up, but I think you’re better served to recondition your tissues with relatively low loads as you ease back into training, rather than reconditioning them with heavy loads once you’ve already regained most of your lost strength.
Wrapping things up
I realize this is a lengthy article, so let’s briefly recap the key points:
- Younger adults can probably “get away with” about a month of training cessation before losing too much strength and muscle mass. Older adults may be able to get away with about two weeks of training cessation. After that, losses accelerate.
- Strength endurance seems to fade a bit faster than maximal strength, and older adults (>60-65 years old) seem to lose strength (and likely muscle) at about twice the rate of younger adults during a period of training cessation.
- Due to the phenomenon of “muscle memory,” the retraining period (the amount of time it takes to regain lost muscle and strength) following a period of training cessation seems to be about half as long as the period of training cessation. So, if you’re out of the gym for 12 weeks, you should be able to regain the vast majority of your lost strength and muscle mass in approximately 6 weeks.
- If you have the time, ability, and inclination to do any training, you can significantly mitigate the losses in strength and muscle mass you’d otherwise experience during a period of total training cessation.
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- I’m aware that a recent meta-analysis has called myonuclei-related mechanisms of muscle memory into question. However, I’d refer you to my previous article on the topic. Studies that employ the most rigorous measurement techniques are the studies most likely to report a preservation of myonuclei, leading me to suspect that the meta-analysis overestimates the extent of myonuclei loss that occurs with muscle atrophy. And, more generally, it’s less a question of whether myonuclei are retained forever, and more a question of whether myonuclei are lost at the same relative rate at which muscle atrophy occurs. A myonuclei-mediated mechanism of muscle memory doesn’t necessarily require true myonuclear permanence.