Understanding the Effects of Exercise on Blood Pressure
BP has 2 components that make up its definition: systolic aka the top number: the arterial measurement of pressure during a heartbeat/ventricular contraction. Diastolic aka the bottom number: the arterial measurement of pressure at rest (1). BP is controlled acutely through sympathetic drive of the autonomic nervous system working on smooth muscles in arteries and increased cardiac output. (2). Blood pressure as a whole is complicated and involves several other organs, like the kidneys controlling blood volume, and will not be covered in this post (3). Pathological values are controversial but generally establish 120/80 as the healthy limit and anything greater as an issue. (4,5A, 5B). That being said 180/110 is the cut off to safely to initiate exercise (6). It’s not that blood pressures can’t exceed 180 mmHg, that’s not a place you want your baseline level to be. In exercise the systolic number increase expectedly, assisting the entire cardiovascular system match the needs of the body. The diastolic number should not fluctuate much, more than 10 mmHg increase is an immediate indication to stop exercise (7). BP should be taken routinely for EVERYONE, as a screen for those you are aware have high BP/ hypertension (HTN) and those who may not be aware. HTN is largely asymptomatic, having no symptoms, but chronic uncontrolled HTN can lead to serious consequences such left ventricular hypertrophy, heart failure, artherosclerosis, and a stroke. Athletes at any age can have HTN (8). Exercise can be prescribed to help control and lower BP. Both aerobic and anaerobic exercises have the potential to lower BP (9). Other strategies can come through diet and medicine. If you have high blood pressure/ HTN it is important to work with a physician to a plan to manage your BP. Other health professionals such as physician assistants, physical therapists, exercise physiologists, athletic trainers, and even personal trainers can be part of a support team you have to manage it.
Sources:
1. Powers, S.K., Howley, E.T. Exercise Physiology – Theory and Application to Fitness and Performance ed. 9th - McGraw Hill (2015), chap.10 pp.190-194.
2. https://www.nature.com/articles/nrn1902
3. https://annals.org/aim/article-abstract/716658/progression-chronic-kidney-disease-role-blood-pressure-control-proteinuria-angiotensin
4. https://www.heart.org/-/media/data-import/downloadables/hypertension-guideline-highlights-flyer-ucm_497841.pdf
5. (A) http://thepafp.org/website/wp-content/uploads/2017/05/2014-JNC-8-Hypertension.pdf, (B) https://sites.jamanetwork.com/jnc8/
6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4369613/
7. https://www.ahajournals.org/doi/full/10.1161/01.CIR.101.6.611
8. https://www.nejm.org/doi/full/10.1056/nejmoa010273
9. Rakobowchuk, M., McGowan, C.L., de Groot, P.C… et al. Endothelial Function of Young Healthy Males Following Whole Body Resistance Training (2005). Journal of Applied Physiology, 98 pp. 2185-2190.