MUSCLE MEMORY

When we think of muscle memory we think about the ability to learn a specific task and perform it accurately and consistently even if we haven’t performed this task for a long period of time. Just like the saying “like riding a bike”. This comes down to neurological changes that, once learned, enables you to recall and perform, ‘Muscle Memory’. (Shea, C. H., & Wulf, G. 2005).

This describes the performance aspects of muscle memory but something that is often described with the same terminology is the idea that your muscles also have a memory of how big they used to be and that you can return to that former state quite quickly compared to the first time achieving this muscle size.

There are a lot of gym terms and ‘bro science’ that often have no weight in science. Typically, opinions and observations from ‘gym bros’ are just gym myths that are often a waste of time and hindrance to long term development than insider knowledge. Although the term muscle memory implies something very bizarre and could be easily waved off, it does in fact, describe a physiological mechanism. No, your old and bigger pre-lockdown muscles don’t have a memory of their former glorious self, but, they do have something very significant, myonuclei.

Myonuclei, what is it?

Myonuclei is the nuclei of a muscle fibre, it is located at the periphery of the fibre in the space between myofibrils and sarcolemma (Shenkman, B. S., et al. 2010). Myonuclei control a specific area (Domain) within the muscle fibre. When the muscle fibre wants to expand and grow, new myonuclei are created to govern the additional space of the newly formed, bigger muscle fibre.

More myonuclei = more muscles

Training & Muscle Hypertrophy

A response to resistance training is muscle hypertrophy - provided progressive overload has been correctly applied, the correct nutritional strategy in place, and enough recovery allowed, the muscles respond to the stimulus by getting bigger and stronger to deal with the stress it is exposed to.

Muscle hypertrophy occurs at different individual rates, some trainees with genetic tendencies can increase size and strength quicker than others. For example, the average time period trainees can expect to see visual changes in physique with muscle hypertrophy is usually within 4-6 weeks, (provided the correct protocols are followed). It’s worth mentioning however, that recent research into Blood Flow Restriction (BFR) training has evidenced muscle hypertrophy in much shorter time periods (Bjørnsen, T., et al. 2019).

With continued months of completing dedicated training blocks tailored toward muscle hypertrophy, the trainee will have developed additional myonuclei and they will be starting to add up. These additional myonuclei will have formed additional layers of muscle fibre and after months of training, the trainee will be sporting the fruits of their labour.

But what happens if I stop training? (lockdown)

De-Training

“If you don’t use it you lose it”

“If you don’t use it you lose it” a phrase often used in relation to training and best describes the de-training experienced when you no longer expose your physiology to a demanding or challenging stress.

The human body is highly adaptive and this has been key to our evolutionary success as a species. Although this may seem like a very basic generalisation, your training, diet, and recovery protocols are just an environment which your body adapts to. Consistently and frequently lifting progressively heavier weights coupled with high levels of protein and optimal recovery periods produces stronger and bigger muscles.

With bigger muscles comes a higher metabolic cost, the brain is geared toward survival and with bigger muscles running at a cost per day, if they are no longer needed for the current environment then they will be reduced to save on energy expenditure. For example, just like a subscription you may be paying month to month, after a while of not using it, you may look to cancel that subscription to save on your outgoing.

After 3-4 weeks of no training we start to see a reduction in muscle size, this isn’t a reduction in muscle fibre however, just the muscle glycogen starts to become depleted causing the muscle to shrink in appearance.

After the 4 week mark, we start to see reductions in muscle fibres and strength which increases as the weeks go on (again this depends on the individual, activity levels, calorie consumption and protein intake). Strength and size will drop off at different rates, though we typically see around a 10-20% reduction of gains.

With the muscle fibres starting to reduce in size and number, the myonuclei responsible for those fibres still stick around, moving back into the surrounding muscle fibres ready to be called upon.

Getting Back to the Gym and Resistance Training

Creating stimulus to grow (your muscles) is as easy as getting into the gym and lifting some weights, follow that up with adequate protein and recovery, your muscle will come back ready to deal with the stress again. That said, long term development and continued growth beyond the first few months is where things start to get a bit more complicated.

How many friends do you have that go to the gym for a short period, make some gains but then seem to stagnate? Maybe something you are familiar with yourself through your own experiences?

Short term gains are there to be had by all but it takes strategy and forward planning to continue your growth and progression, a specific element in our online coaching service.

There are some key components to be aware of to help get those myonuclei expanding their domain again.

Training at the correct volume, intensity, and frequency

VolumE

Volume is the amount of work you perform, e.g. session volume, weekly volume etc. It is a huge driver and suggested to be the key factor for muscle hypertrophy (Schoenfeld, B. J., et al. 2019). Whilst the correct volume is dependent on the individual, a range between 10-20 sets per muscle group per week is the ideal range to work within.

Volume can make or break a programme, too much volume will dig the lifter into a hole which they may not be able to get back out of. Messing up weekly volume can ruin an entire training block with under recovering seeping into each session and weeks with the trainee only getting weaker and increasingly less motivated to train.

Too little weekly volume and you aren’t gaining and progressing as quickly as you could be. Finding the optimal balance and then increasing it as you increase your work capacity is key for long term development.

Intensity

Intensity describes the weight on the bar, it was previously thought that hypertrophy could only be achieved with a certain intensity, so lifting lighter weights and training at low percentages of your 1RM is pointless.

This is now accepted not to be the case with numerous studies showing just as much muscle hypertrophy achieved with light load training when compared to lifting with heavier weights when total volume was equated, provided the lighter load training was taken to muscular failure. (Schoenfeld, B. J., et al. 2017).

Two things to be aware of with training at heavy and light loads:

1. When training with heavier loads at 5-12 reps you do not need to train to failure. Due to the heavy loads there is an increase in muscle unit activation to produce high amounts of force needed to shift the heavier weight. This means a high % of the target muscle fibre is stimulated. Training with heavier loads and close to failure using reps in reserve has been shown to be a potent stimulus for muscle hypertrophy.

2. When training with lighter loads at 15-20+ reps, to achieve the muscle building response of the heavier loads, lighter load lifts must be taken to failure. With lighter loads, your body only recruits enough muscle fibre to lift the load. As you continue to go through your reps the muscle fibre starts to fatigue and with this additional fibres are recruited to continue the task. As the fibres continue to fatigue more become recruited, this increases the motor unit activation, increasing the percentage of the target muscle fibre being stimulated.

This is an important concept to understand and it explains why muscle failure must be achieved with these loads.

Frequency

This refers to how frequently you train the target muscle per week. Training the muscle once per week will still move you forward for example, if you consider your training session is pressing a button to grow your muscles, once the button is pressed it is only active for 1-2 days (potentially 3 depending on how hard you press it). However, if the goal is building bigger muscles and you achieve this by pressing the button, doesn’t it make sense to try to press this button as much as possible?

A completely hypothetical number but for example, if it takes 60 presses of the button to achieve your goal, be it bigger pecs or legs, it would make sense to structure your training so you can press this button as much as possible? Getting to the hypothetical target hits quicker?

Applying this idea to your training week, it is optimal to train each muscle 2-3 times per week (Schoenfeld, B. J., et al. 2016). But, don’t forget, you also need to structure your volume and intensity correctly so you are able to train again. Targeting muscles that are still trying to recover does not give any additional gains than if the muscle was left an extra day to recover, and potentially wastes an opportunity to stimulate muscle growth only to acquire extra training fatigue for no benefit.

Conclusion

If you have recently taken a break from resistance training it is quite possible you have lost some muscle size and strength, but don’t worry, your previous training efforts will have created the additional myonuclei that are still within the surrounding muscle fibres. On returning to your training routine, these myonuclei will be active and ready to start moving into the additional muscle fibres created in response to your training.

You can build muscle in any rep range so long as the weekly volume is sufficient, 10-20 sets per week per muscle group. If you are training with heavier loads, implement some autoregulation with reps in reserve and avoid failure, however, if training with lighter loads to optimise hypertrophy, failure sets must be used to get higher levels of motor unit recruitment.

Always be careful with your total volume as too much may put you in a position that you can’t recover from the previous session before moving into the next, reducing your potential to build muscle and increasing your fatigue which will eventually lead to lack of motivation to train and stick to your diet.

Look to optimise your training to fit your lifestyle manipulating your training volume and frequency to effectively stimulate muscle growth as much as possible. Follow your nutritional strategy to feed your body’s recovery and performance.

When your work capacity starts to increase, increase your training load to continue applying stressors.

Stu

References

1. Bjørnsen, T., Wernbom, M., Løvstad, A., Paulsen, G., D’Souza, R. F., Cameron-Smith, D., ... & Raastad, T. (2019). Delayed myonuclear addition, myofiber hypertrophy, and increases in strength with high-frequency low-load blood flow restricted training to volitional failure. Journal of Applied Physiology, 126(3), 578-592.

2. Schoenfeld, B. J., Contreras, B., Krieger, J., Grgic, J., Delcastillo, K., Belliard, R., & Alto, A. (2019). Resistance training volume enhances muscle hypertrophy but not strength in trained men. Medicine and science in sports and exercise, 51(1), 94.

3. Schoenfeld, B. J., Grgic, J., Ogborn, D., & Krieger, J. W. (2017). Strength and hypertrophy adaptations between low-vs. high-load resistance training: a systematic review and meta-analysis. The Journal of Strength & Conditioning Research, 31(12), 3508-3523.

4. Schoenfeld, B. J., Ogborn, D., & Krieger, J. W. (2016). Effects of resistance training frequency on measures of muscle hypertrophy: a systematic review and meta-analysis. Sports Medicine, 46(11), 1689-1697.

5. Shea, C. H., & Wulf, G. (2005). Schema theory: A critical appraisal and reevaluation. Journal of motor behavior, 37(2), 85-102.

6. Shenkman, B. S., Turtikova, O. V., Nemirovskaya, T. L., & Grigoriev, A. I. (2010). Skeletal muscle activity and the fate of myonuclei. Acta Naturae (англоязычная версия), 2(2 (5)).