They know how much muscle you had before you stooped training. So these muscle nuclei seems to acts like ‘memory cells’. So what? Since now the muscle has the same number of muscle nuclei after we stopped training, it is easy to build the muscle back to its previous size. However, recently, studies using different animal models (denervation, unloading, synergic ablation) showed that as muscle atrophies or shrinks due to inactivity or detraining (until 3 months), there is no loss of muscle nuclei as we previously thought! As shown in the picture, the muscle size decreased by 50% (lines) but the muscle nuclie count (stained with green dye) remained the same. And this was supported in studies which showed as muscle shrinks in size, the number of nucleus decreases too. Just like muscle growth, we believed that when we lose muscle, the opposite happens - we lose some nuclei since there is no reason for the extra nuclei to sit around. It has been shown that people who take steroids and people who grow muscle easily have lot more muscle nuclei than normal. The increase in nucleus with muscle growth has been shown in number of studies. So when your muscles get bigger, you have to add more muscle nucleus. So why do muscles need so many nuclei? The nucleus is basically what controls the cell and since your muscles are a lot lot bigger and way more complex than other cells in the body, one or two nuclei just cannot do the job. Unlike other cells, muscle cells have more than one nucleus (probably thousands). The nervous system mechanisms may explain the strength gains, but it doesn’t explain how you can gain back the muscle size so quickly.īut recent studies show that we may have finally solved the mystery of muscle memory How did they solve it? We used to believe this is largely due to the nervous system mechanisms. This phenomenon is called ‘ muscle memory’. However, if you start training back again, you gain the lost muscle or strength within a few weeks - as if the muscle remembers where you left off. Reversal of fibre cross-sectional area with detraining, and only modest improvement with retraining, suggests that much of the retention in strength with detraining and reacquisition of lost strength with retraining reflects neural adaptation.Muscle memory is what? We all know that if you lift weights and stop lifting for a few months (3-6 months), you will lose strength and muscle. The results indicate that elderly men lose some muscle strength following short-term detraining, but that only a brief period of retraining suffices to regain maximal strength. After 8 weeks of retraining, muscle strength returned to trained values, but without a significant change in fibre morphology. However, type I and II fibre cross-sectional area reverted to pretraining values. Of initial strength gains, only 29.9 +/- 5.2% was lost with detraining. Increased strength was accompanied by hypertrophy (P < 0.05) of type I (17.4 +/- 4.1%) and II (25.8 +/- 12.4%) muscle fibres. Muscle strength increased during initial training by 40.4 +/- 5.5% (mean +/- SEM), ranging from 26.0 +/- 5.0 to 83.9 +/- 15.6%, depending on muscle group. Needle biopsies of vastus lateralis muscle were obtained from seven men. Dynamic muscle strength was assessed by the 1-RM method every 2 weeks for 44 weeks. The resistance programme included three sets of eight repetitions at 75% of one-repetition maximum (1-RM), three times per week, for 10 upper and lower body exercises. During the detraining and retraining phase, subjects did not receive rhGH. To investigate the effects of cessation and subsequent resumption of training on muscle strength in elderly men, 11 men (aged 65-77 years), just completing a 24-week randomized controlled trial of recombinant human growth hormone (rhGH) and resistance exercise (rhGH, n = 6 placebo, n = 5), detrained for 12 weeks and subsequently retrained for 8 weeks.
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