Lukus Klawitter M.S
What’s up endurance fam? Here we are stemming off the previous blog post of strength training for the master’s athlete and getting more detailed on how the muscle itself responds to aging. It is well known that physical activity is mandatory for long term health. While aging we naturally produce less anabolic hormones that are needed for growth such as, in a young growing body. Muscle aging is associated with a lot of risks including, decreased capabilities to perform regular physical activity (household chores/activities), falls, and an increased risk for cardiovascular and heart disease.
Into our third decade of life, muscle related loss known as atrophy begins to take place and between 50 and 60 years there is a 2 – 4 % decrease in muscle force production and overtime up to a 35% loss of that force generating capacity due to the loss of fast twitch muscle fibers. Atrophy is a decrease in overall muscle mass, which leads to a loss of force production and aerobic metabolism. Therefore, we see a lessened voluntary neural drive and loss of information connection at the neuromuscular junction, which leads to low motor neuron firing rates. Put simply, we lose the capabilities to produce large amounts of immediate anaerobic power and force.

Muscle aging also has an effect on aerobic metabolism within the muscle. Muscle loss compromises the muscle function and blocks the transportation of oxygen via the blood, which also carries essential nutrients, hormones, and amino acids. This can lead to limited aerobic capacity and regenerative properties post exercise therefore, limiting sustained aerobic power and recovery purposes.
As aging endurance athletes it is important to understand the physiology of the skeletal muscle in the human body and how we can maintain or increase muscle health to increase performance and live a long-term healthy life. Luckily, research on the prevention of muscle aging and exercise is quite robust. Exercise can reverse age related muscle loss and increase force capacity, muscle metabolism, mitochondrial capacity, and muscle recovery. It has been stated that endurance trained masters athletes maintain the size and function of the motor unit, which means keeping the size of the muscle fiber and the information that it receives from the neuron. Exercise and training can also re-generate the innervation of the neuron and the muscle fiber bundle leading to enhanced information to the muscle and more force or power production.

As aging athletes it is important to take some things into consideration. Firstly, athletes that have been training aerobically in some method for many years have laid a very large aerobic base. They are able to get aerobically fit and adapt the mitochondria within the muscle fiber sooner than a new or very young athlete. Therefore, a heavy focus on VO2 and anaerobic sprint work should be emphasized to help maintain the size of the fast twitch muscle fiber and the neuron innervation capabilities for anaerobic power. It is also important to note that recovery and volume at VO2 should be emphasized due to the slowed recovery processes with age. Secondly, adequate protein of 1.2-1.5g of protein per kg of body weight, focusing on quality amino acid consumption, especially lysine to help maintain and build muscle mass and strength. Masters athletes should focus on consuming a minimum of 20-30g of protein every 3-4 hours to help initiate muscle protein synthesis. Lastly, energy intake should not be decreased due to the thought of decreased metabolism. A decrease in energy intake has been researched in master’s endurance athletes and showed that levels of protein, carbohydrates, vitamins, and minerals fall below even the basic RDA values for regular non-training individuals.
If you have any questions, message me on Instagram or email me at lukus@matthansoncoaching.com, keep sawing logs!