You may know that exercise is good for you, but have you ever wondered specifically what exercise is doing for you while you go through a workout? This is part two and we'll be looking at how exercise works your skeletal system! 

Skeletal Muscle

“As we age, there is an age-related loss in skeletal muscle mass and strength, known as sarcopenia” (McCormick & Vasilaki, 2018). In addition, “skeletal muscle capillarization is a determining factor in gas and metabolite exchange, while its impairments may contribute to the development of sarcopenia” (Leuchtmann et al., 2020). Skeletal muscle can decrease with age due to a number of factors typically exacerbated by a sedentary lifestyle. As a result, muscle cells are lost and/or atrophy which decreases both strength and function (Ehrman et al., 2013). 

Regular physical activity can slow these age-related changes. HIIT has been shown to help increase muscle mass and can have a significant increase in the rate of ATP demand compared to at rest (Baker et al., 2010). Furthermore, Leuchtmann et al., (2020) conducted a 12-week study involving elderly men and compared resistance training (RT) to HIIT. They found that RT and HIIT both elicited similar effects of enhancing capillarization and oxidative enzyme activity and RT helped preserve the changes made as a result of HIIT (Leuchtmann et al., 2020). Therefore, if one is considering an exercise program at an elderly age, HIIT has been found to be an effective and efficient method to build muscle and help slow the rate of muscle loss. 

Always be sure to consult your physician when you're starting a new exercise routine. However, more often than not, they will encourage you to start getting active because of the numerous benefits. Each little step, like parking farther away at your destination or making sure to take the stairs, will add up over time. And if you're able to add in regular HIIT sessions, that's even better!

References

Baker, J. S., McCormick, M. C., & Robergs, R. A. (2010). Interaction among Skeletal Muscle Metabolic Energy Systems during Intense Exercise. Journal of nutrition and metabolism, 2010, 905612. https://doi.org/10.1155/2010/905612

Ehrman, Gordon, Visich, & Keteyian. (2013). Clinical Exercise Physiology. Human Kinetics.

Leuchtmann, A. B., Mueller, S. M., Aguayo, D., Petersen, J. A., Ligon-Auer, M., Flück, M., Jung, H. H., & Toigo, M. (2020). Resistance training preserves high-intensity interval training induced improvements in skeletal muscle capillarization of healthy old men: a randomized controlled trial. Scientific reports, 10(1), 6578. https://doi.org/10.1038/s41598-020-63490-x 

McCormick, R., & Vasilaki, A. (2018). Age-related changes in skeletal muscle: changes to life-style as a therapy. Biogerontology, 19(6), 519–536. https://doi.org/10.1007/s10522-018-9775-3