Muscle Memory-Is it real or just wishful thinking?

Muscle Memory…a term most have heard at some point in their lives, but is it real or just wishful thinking?

Especially now with the Covid crisis, people have been so thrown off track when it comes to exercise and their usual training methods.  An item or two at home has had to take the place of hi-intensity classes or multiple pieces of equipment that complimented one another to provide muscular mass and body fat burn potential.

Before we approach the subject of Muscle Memory, let’s discuss its flip side, muscle loss or disuse atrophy.

How long it takes for muscles to atrophy

• Muscles start to atrophy after 2-3 weeks. 

• You look smaller during the first weeks of detraining because your muscle glycogen and water stores shrink.

• Bed rest and limb immobilization speed up muscle atrophy.

Strength loss when detraining

• Strength can be maintained without training up to 3-4 weeks, but is gradually lost thereafter.

Endurance loss

• Endurance performance decreases by 4 to 25% after 3-4 weeks.

• Beginners can maintain endurance performance for at least 2 weeks without training.

• VO2 max declines by 6 to 20% in highly trained athletes at around 4 weeks of detraining. Recent VO2max gains can be reversed after 4 weeks.

Now the good news:

Usually, muscle mass comes back quickly when retraining because of muscle memory.

When you stop doing resistance training, you gradually lose some of the strength and muscle tissue you worked so hard to build. Here’s the good news....your muscles really do have “memory,” the ability to quickly regain the strength you lost as a result of taking time off.  Muscle memory is a phenomenon that’s well-described and one that anyone who resistance trains can appreciate, especially when they take a break from training. The question is: How do muscles “remember?”

Muscle Memory at the Muscle Cell Level

Most cells in your body have only one nucleus. An exception to this rule is muscle cells. Cells that make up your muscles are “multi-nucleated,” meaning they have more than one nucleus.  In fact, muscle cells have hundreds and sometimes thousands of nuclei. When you progressively overload your muscles through resistance training, muscle cells produce even more nuclei. The additional nuclei are donated by “satellite cells,” stem cells that fuse with muscle cells and transfer their nuclei. As a result, muscle cells have more nuclei to make new muscle proteins. This explains at the cellular level how muscles grow larger in response to training.

Now, let’s say you have to take a month or two off from training. Even though the muscle begins to shrink from lack of stimulation, the new nuclei in the muscle cells are retained. In fact, those extra nuclei stick around for 3 months or more after you stop training. This means when you get back to training, the nuclei are still there, ready to re-start the process of making new proteins to help you recover the muscle mass and strength you lost quickly.

Muscle Memory: The Role Your Brain Plays

Prior to the discovery that muscle nuclei formed in response to resistance training stick around for a while, researchers believed muscle memory was purely a brain phenomenon – your brain forges connections with your muscles that are preserved even after you stop training. It’s an example of “practice makes perfect” since the more you do the activity and reinforce those pathways, the easier it is to jump back in and do it smoothly without going through a relearning process.

When you do an activity, like sets of biceps curls, the proprioceptors in your muscles and tendons send information to your brain about the position of your muscles in 3-dimensional space. The brain uses this information to send input back to your muscles, telling them when to contract, at what angle and with what force. Over time, this interaction between brain and muscles builds communication pathways that become stronger each time you train.

If you stop training for a while and then return, the “roads” or pathways built between your brain and muscles are still there. As a result, you’re still capable of doing those movements even if you haven’t trained in a while. You don’t have to start over again from scratch. That’s good to know, isn’t it?

Think about what it was like when you learned to ride a bike. It took you time to get the hang of it, but once you did, you could park your bike and still climb back on years later and take a spin. The more you perform an activity, the deeper the connections you form between brain and muscle and the easier it is to pick the same skill back up. You may be a little rusty, but you’re not starting all over again.

Pathways forged between brain and muscle also explain why we can do some things automatically. For example, when you sit down to type a letter or play a musical instrument you don’t have to consciously think about where each letter or note is on the keypad or instrument. This assumes you learned where the keys on the keypad are in the first place and aren’t typing with two fingers.

Not to undermine the brain-muscle connection, but the fact that muscle nuclei formed during training are retained changes the way we think of muscle memory. Structural changes have taken place in the muscle that isn’t lost when you stop training for a few months. Once you begin lifting again, those nuclei quickly begin synthesizing new muscle proteins so you can recoup your gains. You don’t have to rebuild new muscle nuclei to jumpstart muscle protein metabolism.

This miracle within our bodies was confirmed in a study performed at Keele University which demonstrated for the first time that human muscles possess a 'memory' of earlier growth -- at the DNA level.

The researchers confirmed that periods of skeletal muscle growth are 'remembered' by the genes in the muscle, helping them to grow larger later in life.

The study, published in Scientific Reports, confirmed that for those of us who were active and athletic when we were younger, the advantage is there for improved results when exercising at a later point in time.

So, for those who were derailed when the Covid crisis disrupted our personal and business lives, greatly impacting how we tried to retain our health and the fitness levels that we worked so hard to achieve, here are some interim pointers in salvaging what you busted your butts to initially achieve:

• To maintain strength during detraining, train at least once per week (for beginners). Trained lifters could maintain strength gains with eccentric training.

• To maintain hypertrophy during detraining, train at least once per week (for beginners). There’s not much long-term data for trained lifters, but eccentric training could help.

• To maintain endurance during detraining, you can lower training volume by 60 to 90%, training frequency by no more than 20-30% in athletes but beginners can reduce it by 50 to 70%. Training intensity should be the same.

• If injured, use alternative training forms such as underwater running. 

We all know that taking off from training wasn’t part of your plan, but recouping your gains is easier and faster the second time around because you’ve already laid the groundwork.  

Muscle memory is a real phenomenon that works in your favor as long as you learned how to train properly the first time. So, if you’re disappointed when you’ve looked in the mirror or stepped on the scale lately don’t focus on what you see…have faith that your muscles are primed to rebuild once you begin training again.

You could be back to where you were when your life was turned upside down in less time that you ever imagined, what is most important is that you maintain a POSITIVE mental outlook and that you once again regularly take care of yourself and your health through exercise, proper diet, stress reduction (I know easier said than done), proper sleep, and above all STAY SAFE!