Generally hypertrophy becomes evident after around 3-4 weeks of resistance training
(1,2,3), however detraining periods have also been considered. One study examined
training and detraining in 4 subjects during 100 days. The same rate of
atrophy was observed during the detraining phase (40 days) as for the
hypertrophy rate during the training phase (60 days) (4).
Another study examined subjects across age and gender
groups using the same relative training stimulus (5). After 9 weeks of training muscle volume was twice as much
for men (across ages) as for the
women (across ages), but after 31 weeks of detraining men also experienced the greater loss of muscle mass; and muscle
volume returned to original pre-training muscle size only for the females.
However other studies have shown a lesser degree of atrophy or no significant
atrophy at all (6,7). A detraining phase of 3 weeks appears to have not
much of a difference in muscle mass and adaptations (6). In another similar
study by the same authors, while one group trained continuously for 24 weeks
the other group performed three cycles of 6-week training (or retraining), with
3-week detraining periods between training cycles; improvements in muscle CSA
and strength were similar between groups (7).
(In both studies the rate of increase in muscle CSA
and 1-RM decreased gradually after 6 week for the control group, while for both
studies the experimental group increase in muscle CSA and strength was better,
suggesting a more efficient response
after a detraining phase.)
As discussed in a previous article, full range of motion is more beneficial for hypertrophy adaptations and strength. In a
study examining the differences of training at a longer (LR) compared with a
shorter (SR) range of motion (ROM) and the time course of any changes during
detraining, the short range of motion group
experienced a more rapid relative loss of postexercise increases in strength
than that experienced by the longer range of motion group (8). Other
differences were also observed in distal anatomical cross-sectional area,
fascicle length, and subcutaneous fat in favor of the longer range of muscle
group, after 8 weeks.
References:
1. O. R.
Seynnes , M. de Boer , M. V. Narici. Skeletal
hypertrophy and architectural changes in response to high--intensity resistance
training. J Appl Physiol 2007; 102: 368-73.
2. Abe T, DeHoyos DV, Pollock ML. Time course for strength
and muscle thickness changes following upper and lower body resistance training
in men and women. Eur J Appl Physiol 2000; 81: 174-80.
3. Ogasawara R, Thiebaud RS, Loenneke JP, et al. Time
course for arm and chest muscle thickness changes following bench press
training. Interventional Med Appl Sci 2012; 4(4): 217-20
4. Narici MV, Roi GS, Landoni. Changes in force,
crosssectional area and neural activation during strength training and
detraining of the human quadriceps. Eur J Appl Physiol 1989; 59: 310-9.
5. Ivey FM, Roth SM, Ferrell RE, et al. Effects of
age, gender, and myostatin genotype on the hypertrophic response to heavy
resistance strength training. J Gerontol Med Sci 2000; 55(11): M641-748.
6. Ogasawara R, Yasuda T, Sakamaki M, et al. Effects
of periodic and continued resistance training on muscle CSA and strength in
previously untrained men. Clin Physiol Funct Imaging 2011; 31: 399-404.
7. Ogasawara R, Yasuda T, Ishii N, et al. Comparison
of muscle hypertrophy following 6-month of continuous and periodic strength
training. Eur J Appl Physiol 2013; 113: 975-85.
8. McMahon GE1, Morse CI, Burden A, Winwood
K, Onambélé GL. Impact of range of motion during ecologically valid resistance training
protocols on muscle size, subcutaneous fat, and strength. J Strength Cond Res. 2014
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