"Is everyone at home taking some time off to recover + prime future muscle growth?"

Systematically periodized trainig routines (yet often with only one detraining phase per season) are among the various reasons professional athletes are at a lower risk of developing the athletes' triad than overambitious gymrats.

"[A]fter short-term (>1 month) cessation of training (detraining), muscle adaptation responses may return to their initial levels, and the effects of retraining after short-term cessation on muscle growth are comparable with those observed during the early phase of training." (Ogasawara. 2012)

*Why is it problematic that the study participants were untrained? With the initial growth response to weight training being much more pronounced in previously untrained individuals, it is very likely that the same is going to be the case for the similarly pronounced response to "retraining" after a three-week detraining phase. This does not generally speak against the usefulness and maybe even the need for well-planned periodization in advanced trainees, but it renders the concept of a complete three weeks lay-off (=classic detraining) at least questionable. Read my comments towards the end of this post for possibly better-suited alternatives.

"[...] assuming that the decrease in thigh muscle CSA during 3 weeks of detraining is 2.1 % (estimated at 0.10 % per day and 21 days), and the increase in muscle CSA during 6 weeks of retraining is 5.9 % (estimated at 0.14 % per day and 42 days), the increase in muscle CSA during a 3-week detraining/6-week retraining period (estimated at 0.06 % per day during 9 weeks) would be 3.8 %. The estimated value of 0.06 % per day is similar to values obtained in previous studies, where the average increase in thigh muscle CSA was reportedly around 0.05 % per day." (Ogasawara. 2012)

"Both groups performed high-intensity, free-weight bench press exercise training 3 days per week. [...] Training intensity was set at 75 % of one repetition (rep) maximum (1-RM), and training volume was set at 3 sets of 10 reps (with 2–3 min rest between sets). To ensure an adequate training load, all training sessions were overseen by a supervisor. Training load was renewed every 3 weeks, and, if subjects could perform 12 reps or more at the 3rd set during training sessions, the training load was increased by about 5 % for the next training session." (Ogasawara. 2012)

Figure 1: Relative changes 1-RM and maximal voluntary contraction (MVC) + time-course of these changes (left); time-course of relative changes in cross sectional area in triceps bracchii (top, right) and pectoralis major (bottom, right; based on Ogasawara. 2012)

Figure 2: Just in case you've forgotten about that - different muscles react in different ways to modulations in training volume. So why would they react identically to off-times? Moreover if legs benefit most from a higher training volume, wouldn't it be likely that they suffer most from longer periods of detraining?

Detailed data on the pre / post body composition. The identical increase in body weight (+2%) is not of interest to me (and probably to only very few of you) and the simple assumption that identical body weight gain + identical CSA gains of triceps brachii (TB) and pectoralis major (PM) would translate into identical changes in total body fatness / muscularity is about is unwarranted (see link in figure 2). A realistic full-body workout routine: The low volume chest only workout regimen is not just unrepresentative of a real workout protocol, it does also raise the question if other body parts as the legs, for example, would not respond very differently to a three week lay-off phase (see figure 2 + respective reference to a previous post on training volume).

not

Possible alternatives for advanced athletes: Rather than taking a complete 3-week time out from all athletic endeavors, you can to stick to ...

a maximal complete off-time of 1-week (as in not doing anything),

(as in not doing anything), a 2-3 weeks of active off time (as in going on vacation w/ regular non-exhaustive physical activity), or

(as in going on vacation w/ regular non-exhaustive physical activity), or the incorporation of a tapering regimen as described in Part VI of the Step By Step Guide to Your Own Workout Alternatively you can combine / mix one or two of these (you won't go on vacation every 6 weeks, will you?) Rather than taking a complete 3-week time out from all athletic endeavors, you can to stick to ...Alternatively you can combine / mix one or two of these (you won't go on vacation every 6 weeks, will you?)

The discrepancy between the accrual of skeletal muscle protein and the loss of the latter in response to total laziness gets lower, if not totally reversed, the bigger you get. Consequently the added bonus of "faster gains" upon recommencing the training will diminish, or even disappear completely.

Many more or less "professional" trainees follow dietary regimen that are not sustainable, when they are not training. During a complete time-off of three weeks without any alternative "outlet", the chances to gain fat are thus much higher for them, than for the average beginner, who - if anything - guzzles a protein shake after each of his three weekly training sessions.

Competitive amateur athletes who are training 5x a week or more actually run the risk of both, physical and psychological withdrawl symptoms, when they simply stop training altogether (another argument in favor taper, if you asked me; see infobox on the right).

If you are not the one in a million expection from the rule,

you cannot simply "play this by ear"!

in advance

Bemben DA, Fetters NL, Bemben MG, Nabavi N, Koh ET. Musculoskeletal responses to high- and low-intensity resistance training in early postmenopausal women. Med Sci Sports Exerc. 2000: 32:1949–1957

Hakkinen K, Newton RU, Gordon SE, McCormick M, Volek JS, Nindl BC, Gotshalk LA, Campbell WW, Evans WJ, Hakkinen A, Humphries BJ, Kraemer WJ. Changes in muscle morphology, electromyographic activity, and force production characteristics during progressive strength training in young and older men. J Gerontol A Biol Sci Med Sci. 1998; 53:B415–B423

Hakkinen K, Alen M, Kallinen M, Newton RU, Kraemer WJ. Neuromuscular adaptation during prolonged strength training, detraining and re-strength-training in middle-aged and elderly

people. Eur J Appl Physiol. 2000; 83:51–62.

people. Eur J Appl Physiol. 2000; 83:51–62. Hakkinen K, Alen M, Kraemer WJ, Gorostiaga E, Izquierdo M, Rusko H, Mikkola J, Hakkinen A, Valkeinen H, Kaarakainen E, Romu S, Erola V, Ahtiainen J, Paavolainen L. Neuromuscular adaptations during concurrent strength and endurance training versus strength training. Eur J Appl Physiol. 2003; 89:42–52

Hulmi JJ, Kovanen V, Selanne H, Kraemer WJ, Hakkinen K, Mero AA. Acute and long-term effects of resistance exercise with or without protein ingestion on muscle hypertrophy and gene expression. Amino Acids. 2009; 37:297–308.

Narici MV, Hoppeler H, Kayser B, Landoni L, Claassen H, Gavardi C, Conti M, Cerretelli P. Human quadriceps crosssectional area, torque and neural activation during 6 months strength training. Acta Physiol Scand. 1996; 157:175–186

Ogasawara R, Yasuda T, Sakamaki M, Ozaki H, Abe T. Effects of periodic and continued resistance training on muscle CSA and strength in previously untrained men. Clin Physiol Funct Imaging. 2011 Sep;31(5):399-404.

Ogasawara R, Yasuda T, Ishii N, Abe T. Comparison of muscle hypertrophy following 6-month of continuous and periodic strength training. Eur J Appl Physiol. Oct 06, 2012.

Human beings are creatures of habit. This is particularly true, when it comes to those things and procedures we either like or enjoy or have found to be highly conducive to our goals, in the past. Just like some people simply won't drop their belovedand, although they know that these sugar bombs are bad for them, and others tend to stick to whatever dietary regimen has allowed them to lose 20lbs of body weight in the past, despite the fact that this "trick" has long ceased working for them, many "recreationally active" individuals (aka gymrats) are totally reluctant to any form of carefully planned deviation of their training regimen.If anything, switching gears from a more hypertrophy to a more strength training oriented program, or vice versa, is probably the one modification most trainees could come to terms with. The notion to take one, let alone three weeks off after the completion of a 6 weeks mesocycle, on the other hand, scares the hack out of 99% of the ambitious strength trainees. Unjustly, as a study that's been published less than one week ago in the online edition of thegoes to show you (Ogasawara. 2012).As surprising as it may sound to the "I will lose my precious muscle" faction, the results of the study Riki Ogasawara and his colleagues from theconducted do actually just confirm what we knew all along:If we further acknowledge that the loss of protein from the muscle during the detraining phase is much slower than the rapid gain, during the early weeks of (re-)training, it should be obvious that any retraining phase will lead to overall increments in skeletal muscle cross sectional area that will easily overcompensate the small amount of size your muscles will have lost during the comparatively short phase without physical exercise.Based on the actual results of previous research by Narici et al, Bemben et al. Hakkinen et al. and Hulmi et al., Ogosaware et al. propose the following example to illustrate this effect:Well, I see this alone can't convince you, right? What about the detailed results of Ogasawara very own study, then? Allegedly, it was done in untrained individuals*, 14 young men (age 25 ± 3 years, standing height 1.72 ± 0.06 m, body mass 65 ± 10 kg), but the results the training regimen the researchers characterize as follows,speak for themselves and were virtually identical in both groups - regardless of whether the subjects trained for 24-weeks continuously (CTR), or performed their regimen in the form of two cycles of 3-week detraining/6-week retraining periods after an initial 6-week mesocycle.Aside from the already mentioned training status of the study participants there are yet two other things I am missing in this study:As far as theandspecific gains in muscle size and strengths in strength training newbies are concerned, the results of the study at hand do however add o the initially mentioned practicability of a simplistic, but effective "6 weeks on, 3 weeks off" approach to periodization, which - and this is a novel finding compared to Ogasawara's study from last year (Ogasawara. 2011) - does still work even in the third mesocycle (take another look atthe "catch up growth" does not diminish!).Despite the fact that the last mentioned sustainability of this approach over a pretty long time period (24 weeks, i.e. 3x complete macrocycles) would indicate that a similar approach will work for trained (maybe even elite) athletes as well, I am pretty convinced that a period of three weeks of complete idleness isthe optimal periodization strategy for advanced trainees, because:Regardless of which of the alternatives in the blue infobox next to the three arguments that make a complete 3-week lay off at least questionable for advanced / professional trainees you pick, if you decide against the, there is one thing you should keep in mind:Periodization requires planning and planning is doneand not in aor. Alright?