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 three and we'll be looking at how exercise works your cardiovascular system! 

Cardiovascular System

The cardiovascular system goes through many changes as a result of the normal aging process. These changes also increase the risk and prevalence of cardiovascular disease because many of the associated factors of heart disease also underlie the age-related changes that take place (Najjar et al., 2007). As a result of age-related arterial stiffening and thickening, this reduces vasodilation capacity, reduces maximal heart rate and subsequently lowers peak aerobic capacity, and causes left ventricular hypertrophy that may lead to hypertension (Ehrman et al., 2013). A sedentary lifestyle in addition to other poor habits such as improper nutrition and smoking only exacerbates the almost inevitable issues.

Regular physical activity can slow or potentially even prevent the detrimental effects associated with aging and declining cardiovascular health, and several recent articles have demonstrated that HIIT is very effective at this. Essentially, HIIT helps train the cardiovascular and respiratory systems by exercising at high intensities (85%-90% maxHR) for short bursts of time and allowing for a short recovery before starting a high-intensity burst again. In an article by Coswig et al., (2020), this 8-week study involving 46 elderly, female volunteers (~80 years old) were divided into a HIIT group, moderate-intensity interval training (MIIT) group, and a moderate-intensity continuous training (MICT) group. They found that HIIT provided greater overall benefits for body composition, functional performance, reduced resting heart rate, lowered blood pressure, and less pronounced effects of detraining compared to MIIT and MICT (Coswig et al., 2020). Other research found improvements in HR, blood pressure levels and baroreflex activity, and VO2max values (Sant'Ana et al., 2020). Another study found a lower all-cause mortality trend after HIIT compared to MICT (Stensvold et al., 2020). Finally, the positive cardiovascular changes following HIIT have been found to be comparable or better than MIIT or MICT (Winett & Ogletree, 2019). Therefore, HIIT is a very valuable way to train elderly individuals in order to help slow the normal aging process of the cardiovascular system.       

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

Coswig, V. S., Barbalho, M., Raiol, R., Del Vecchio, F. B., Ramirez-Campillo, R., & Gentil, P. (2020). Effects of high vs moderate-intensity intermittent training on functionality, resting heart rate and blood pressure of elderly women. Journal of translational medicine, 18(1), 88. https://doi.org/10.1186/s12967-020-02261-8 

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

Najjar S.S., Gerstenblith G., Lakatta E.G. (2007) Aging and the Cardiovascular System. In: Willerson J.T., Wellens H.J.J., Cohn J.N., Holmes D.R. (eds) Cardiovascular Medicine. Springer, London. https://doi.org/10.1007/978-1-84628-715-2_118 

Sant'Ana, L. O., Machado, S., Ribeiro, A., Dos Reis, N. R., Campos, Y., da Silva, J., Scartoni, F. R., Brown, A. F., Monteiro, E. R., Novaes, J., Vianna, J. M., & Budde, H. (2020). Effects of Cardiovascular Interval Training in Healthy Elderly Subjects: A Systematic Review. Frontiers in physiology, 11, 739. https://doi.org/10.3389/fphys.2020.00739 

Stensvold, D., Viken, H., Steinshamn, S. L., Dalen, H., Støylen, A., Loennechen, J. P., Reitlo, L. S., Zisko, N., Bækkerud, F. H., Tari, A. R., Sandbakk, S. B., Carlsen, T., Ingebrigtsen, J. E., Lydersen, S., Mattsson, E., Anderssen, S. A., Fiatarone Singh, M. A., Coombes, J. S., Skogvoll, E., Vatten, L. J., … Wisløff, U. (2020). Effect of exercise training for five years on all cause mortality in older adults-the Generation 100 study: randomised controlled trial. BMJ (Clinical research ed.), 371, m3485. https://doi.org/10.1136/bmj.m3485 

Winett, R. A., & Ogletree, A. M. (2019). Evidence-Based, High-Intensity Exercise and Physical Activity for Compressing Morbidity in Older Adults: A Narrative Review. Innovation in aging, 3(2), igz020. https://doi.org/10.1093/geroni/igz020