Muscle memory demystified
Many of us have taken time off from gym, or been forced to stop training due to an injury or forced recovery. This generally leads to a certain degree of muscle atrophy and strength loss, the severity of which is directly linked to the amount of time you remain sedentary.
However, when the time comes to get back into training those athletes whose bodies have been conditioned over a number years, through systematic, periodised and scientifically-based training programmes will regain muscle size and strength much faster than someone whose body is perhaps less conditioned to training, or is starting to train with weights for the first time. This is due to a phenomenon commonly referred to as muscle memory.
Muscle memory refers to improved neuromuscular facilitation, which is the process of the neuromuscular system learning and memorising motor skills through the repeated training of a specific movement. This process is brain-muscle memory or motor memory, but muscle memory also refers to the stimulation of the bodies adaptive response, which induces a physiological change above normal levels.
As muscle adapts to training, the subsequent changes form a part of its muscle memory as the muscles become accustomed to certain activities.
As muscle adapts to training, the subsequent changes form a part of its muscle memory as the muscles become accustomed to certain activities. It is this accustomisation that allows someone to return to their previous levels of size and strength, following a long lay-off, in a shorter period of time than it took to get there when they first started training.
There are a number of different explanations for this phenomenon. However, the most common scientific explanation is that when you start weight training for the first time your body has to develop various physiological adaptions from scratch, most importantly the neuro-muscular junction. The neurons (nerve cells) that innervate your muscles stimulate your muscle fibres (muscle cells) to contract with a force that allows you to lift a certain amount of weight. When starting out only a small percentage of the neurons that innervate a particular muscle may be recruited to stimulate muscle fibres to contract. As you progress in your training, through the incremental increases in the weight and stress you place on your muscles, more neurons are incorporated into the muscle contraction. This results in more fibres being stimulated, allowing you to make gains in both muscle size and strength.
Through this development the ability and capacity to recruit a greater percentage of muscle fibers will remain intact following a lay-off from weight training, ensuring the adaptive process is faster and more efficient when you return to the gym. Training also develops the capillary beds surrounding muscle cells, improving the blood supply to the working muscle, thus enhancing nutrient availability. Increased capillary action also assists with the removal of waste and by-products, such as lactic acid and hydrogen ions, which can limit performance and gains. Therefore a developed and established capillary bed, achieved through previous training, will be restored quickly to assist with achieving a muscle stimulus that aids gains in muscle strength and size after a lay-off.
Teaching your muscles to respond appropriately to this new movement, by opening up new neuromuscular pathways, takes time, just like learning a new swimming stroke or to swing a golf club effectively
The improved utilisation of enzymes involved in important biochemical reactions may also impact the effectiveness of muscle memory, as enzymes involved in protein synthesis may increase in concentration and activity following exercise. These enzymes can also quickly return to their former concentrations when someone resumes weight training, thus ‘turning-on’ these processes earlier, allowing you to work out harder, possibly recover faster and gain muscle mass quicker when returning to the gym.
There is however a second way that neurons may be involved in muscle memory, which deals with the development of motor skills through improved neuromuscular facilitation. At the start of a weight training programme your muscles interpret most of the exercises as a new movement. In this case your neurons must develop the appropriate pattern of stimulation to allow for the muscular contraction required by a certain exercise. Teaching your muscles to respond appropriately to this new movement, by opening up new neuromuscular pathways, takes time, just like learning a new swimming stroke or to swing a golf club effectively. When you start to work out again these established neurological pathways accelerate the restoration of neurological control, enabling you to stimulate your muscles more efficiently. This will allow muscle strength and hypertrophy to reach and surpass previous levels in a shorter period of time.
By Pedro van Gaalen, Editor