The Science Behind Skeletal Muscle Memory and Exercise


Imagine that you are a marathon runner, an Olympic swimmer or a professional football player for the NFL. (This shouldn’t be too hard to do as most of us have dreamed about this at one point or another in our lives.)

You train for months and months and even years to run a marathon, swim in the Olympics or play professional football. You train for hours and hours in the weight room, on the field or swimming laps. After years of this consistent training routine, you’re ready for that race or game.

After the event is over, you take a few months off. You rest up and help your body repair before beginning your next training session. After nine months of “rest”, you jump back into the weight room or dive in the pool.

Your muscles should be able to pick right up where they left off, right? Maybe not…

Do Muscles Retain Memory?

We all know the main benefits of exercise: fat and weight loss, building and toning muscle, lowering cholesterol and the risks for other diseases. However, there are also some little-known facts and benefits of exercise that make a big impact, such as improved cognitive functions, reduced depression and anxiety symptoms, sleep quality and even skeletal muscle function.

Although the benefits of exercise are seemingly endless, scientists and medical researchers are still puzzled with just how much regular and consistent exercise positively impacts skeletal muscle functions, and particularly the memory of muscle functions.

In fact, studies have shown that high-intensity and regular, consistent training results in many physiological, structural, biochemical, and transcriptional changes, although many of these changes aren’t permanent after a period of rest from training.

In contrast, other research has shown that regular, consistent, and repetitive exercise and training is often lost if and when an individual stops exercising, leading to the theory that skeletal muscles don’t retain memory.

What the Studies Show

A medical research team at the Karolinska Institutet in Sweden studied the impact of endurance training on the physiological, structural, biochemical, and transcriptional changes of skeletal muscle memory in endurance and high-intensity training.

As a part of the study, researchers recruited 23 individuals to participate in the study over a three-month period and a nine-month period respectively.

The first three-month training period, one leg underwent significant training. After nine months of careful study, 12 out of the 23 participants participated in a second training that involved training both legs.

After performing a biopsy from both legs before and after each training session, it was concluded that muscle cells represented approximately 3400 genes differently as a result of endurance, training, and exercise.

Data Analysis and Discovery

The data output and analysis of this study showed that the outcome of the performance tests conducted were collected at different points throughout the study. The trained leg that went through training through both time periods was compared with the untrained leg.

Although there were a number of transcriptional changes as a direct result and impact of exercise, after a nine-month period of no training or exercise, those specific exercise and training-induced differences were no longer present in the trained and untrained legs, leading medical researchers and biologists to believe that skeletal muscle cannot retain memory.

Authors of the study explain, “Although there were several differences in the physiological and transcriptional responses to repeated training, no coherent evidence of an endurance training-induced transcriptional skeletal muscle memory was found.”

Nothing Tastes as Good as GENES Feel…

Skeletal muscle is highly adaptable to different environments and conditions, such as regular, consistent endurance and even high-intensity training. In the study discussed, as well as many others, individuals who participate in regular exercise have a particular gene present in their skeletal muscle tissue.

The presence of this gene has piqued researchers’ interest levels, and their studies and persistent research have shown that this gene can be regulated with different variations of training.

This conclusion also shows that the presence of this gene is also associated with proteins, which are also present in the post-training skeletal muscle tissue.

Regular and consistent exercise actually changes the activity of the gene, promoting the development and presence of new proteins. Now, you would think that the proteins released by the gene would remain dominant and present even throughout a rest period, or a period without consistent training. However, studies are showing quite the opposite…

Anyone trying to get on the weight loss and fitness train have likely heard the motivating quote, “Nothing feels as good as skinny feels” to help them maintain discipline in eating right, dieting, and exercise. And although those skinny “genes” feel great after months and months of rigorous, highly intensive training, we may understand just really what happens with our “genes” when we give up exercise.

If we give up on exercise and forget all of our hard work and diets, those skinny “genes” become a distant memory – both on the inside and the outside.

In the End, We Are All Different…

Although extensive studies and research have been dedicated to the study we outlined above, the truth is that a global study has yet to be conducted. With that fact to consider, it is possible that other individuals who follow the same training and endurance track followed by a long-term period of rest may find that their muscles do “remember” a training sequence, making it easier to pick back up where they left off.

However, there is also a lack of studies and research that thoroughly investigate the results of consistent, regular training in the same individual.

All in all, these situations have gained the interest of medical researchers, biologists, and scientists, and we can certainly expect to see more time, information, and long-term research being dedicated to this theory.