Physical Activity and Exercise - Part 1

With the holiday season in full swing, I am preparing myself for large calorie consumption and New Year's resolutions. A resolution heard around the world: exercise more in the new year. Before I go further, I want to give a shoutout to Brentsen for his series on prescribing exercise. Many of us at RxTeach are fanatics of exercise and physical activity, so I would like to add to the discussion. I have planned a two-part series on aerobic and anaerobic exercise and some of its benefits related to diabetes and hypertension. The second part, planned for release next month, will discuss aerobic and anaerobic exercise regimens as well as the utility of weight training.

I wanted to write about this topic now given that New Year’s resolutions have started or will occur soon. In addition, I find all forms of exercise to be extremely therapeutic. From a public health perspective, there is a need to continue promoting the necessity for and importance of exercise. According to the Human Services Office of Disease Prevention and Health Promotion (ODPHP), 80% of adults do not meet the guidelines for both aerobic and anaerobic exercise.¹ The lack of physical activity is linked to about $117 billion in annual healthcare costs as well as about 10% of premature mortality.¹ Participating in physical activity is essential for maintaining and improving our health and well-being. 

The American Heart Association

To begin, let's highlight the physical activity recommendations from the American Heart Association (AHA). The AHA recommendations are based on the Physical Activity Guidelines for Americans 2^nd Edition published by the US Department of Health and ODPHP. The AHA recommendation for adults 18 years and over include:³

• At least 150 minutes per week of moderate-intensity aerobic activity, 75 minutes per week of vigorous aerobic activity, or a combination of both. preferably spread throughout the week.
• Add moderate- to high-intensity muscle-strengthening activity, such as resistance or weights, at least 2 days per week.
• Spend less time sitting. Even light-intensity activity can offset some of the risks of being sedentary.
• Gain even more benefits by being active at least 300 minutes, or 5 hours, per week.
• Increase the amount and intensity gradually over time.

For those with children, the AHA recommendations include:²

• Children 3-5 years old should be physically active and have plenty of opportunities to move throughout the day.
• Kids 6-17 years old should get at least 60 minutes per day of moderate- to vigorous-intensity physical activity, mostly aerobic.
• Include vigorous-intensity activity on at least 3 days per week.
• Include muscle- and bone-strengthening activities on at least 3 days per week.
• Increase the amount and intensity gradually over time.

Key takeaways to highlight from the above recommendations are to increase physical activity duration and intensity over time for adults and children and keep children as physically active as possible as they continue to grow and develop. 

A common assessment of physical activity intensity is through heart rate. The below table shows target heart rate zones for different ages. We have a previous article on heart rate zone training linked below if you are interested in more information.

Table 1: AHA Target Heart Rate and Estimated Maximum Heart Rate by Age⁴

The target heart rate during moderate-intensity activities is between 50%-70% of the maximum heart rate, and the target heart rate during vigorous-intensity activity is between 70%-85% of the maximum heart rate.⁴ If you are new to your exercise plan, aim for the lower range of your target zone, 50%, and gradually increase duration and intensity. Over time, you will be able to achieve around 85% of your maximum heart rate.

Important Note:

The ODPHP guidelines discussion of intensity includes a term called absolute intensity, which is described as the rate of work being performed without considering the physiologic capacity of an individual.¹ Absolute intensity is measured through MET (the metabolic equivalent of task). One MET is the rate of energy expenditure while sitting at rest and corresponds to an oxygen uptake of 3.5 milliliters per kilogram of body weight per minute. Light-intensity activity requires less than 3.0 METs, moderate-intensity activity requires 3.0-5.9 METs, and vigorous-intensity activity requires 6.0 or more METs. For those interested in taking a deeper dive into the science of exercise from a kinesiology perspective, please consider reading the publicly available articles from the Journal of Applied Physiology and Clinical Cardiology discussing METs. 

Throughout our respective schooling, we have learned about the association between exercise and diabetes as well as exercise and hypertension. I am including highlights of the association in this article due to the prevalence of diabetes and hypertension in the US. I cannot stress enough the importance of regular exercise for individuals who have diabetes and/or hypertension. I hope that the below benefits can help empower individuals to begin, continue, or gradually increase their exercise regimens. At the same time, the below benefits can be utilized as talking points for respective family and friends who may be reluctant to participate in regular exercise. 

Key benefits of exercise for diabetes include:

1. In individuals with type 1 diabetes, aerobic exercise increased cardiorespiratory fitness, decreased insulin resistance, improved lipid levels, and improved endothelial function.^5,6
2. In individuals with type 2 diabetes, aerobic exercise reduced A1C, triglycerides, blood pressure, and insulin resistance.^{5, 7}
3. Moderate to high volumes of aerobic activity are associated with substantially lower cardiovascular and overall mortality risks in both type 1 and type 2 diabetes.^{5, 8}
4. High-intensity interval training, a form of anaerobic exercise, results in increased skeletal muscle oxidative capacity, insulin sensitivity, and glycemic control in adults with type 2 diabetes. It can also be performed without deterioration in glycemic control in adults with type 1 diabetes.^5,9

Key benefits of exercise for hypertension include: 

1. Aerobic and anaerobic exercise has been shown to reduce blood pressure, body weight, risk of stroke or heart attack, and risk of hypertension.^10,11
2. Aerobic and anaerobic exercise results in reduced systolic and diastolic blood pressure, body mass index, and low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) cholesterol as well as an increase in high-density lipoprotein (HDL) cholesterol.^10,11
   1. This results in decreased atherosclerotic cardiovascular disease (ASCVD) risk, which correlates to improved blood flow and reduced risk of hypertension, heart attack, or stroke.
3. Aerobic and anaerobic exercise has shown strong correlations with prolonged rapid eye movement (REM) sleep and increased levels of endorphins. This has been associated with reduced stress and improved general mood, which has been shown to reduce the risk of hypertension.¹²
4. Aerobic and anaerobic exercise has been shown to strengthen the heart muscle, which improves the heart’s ability to pump blood to the lungs, organs, and muscles throughout the body. The heart pumping blood more efficiently has been shown to result in increased SpO2 levels and reduced risk of hypertension, heart attack, or stroke.¹³

Overall, physical activity has therapeutic effects, can reduce comorbidities, and can prevent risk factors that contribute to the progression of chronic diseases. Physical activity helps prevent heart disease and factors related to the progression of diabetes and hypertension by, among others, decreasing body weight, low-density cholesterol, elevated hemoglobin A1c, and risk of cardiovascular disease mortality. Participating in a consistent physical activity regimen is beneficial because moving towards greater amounts of physical activity and its intensity per week results in greater benefits. Simply put, physical activity is the gift that keeps on giving. Being physically active is one of the most important steps we can take to improve our overall health. As we near the new year, aim to push your exercise boundaries in a safe and responsible manner. Find activities you enjoy to aid in a consistent exercise regimen. Lastly, physical activity and exercise are a positive feedback loop where results fuel motivation.

Wishing you and yours a very Happy Thanksgiving!

References:

1. Piercy KL, et al. The Physical Activity Guidelines for Americans. JAMA. 2018;320(19):2020-2028. doi: 10.1001/jama.2018.14854.
2. World Health Organization. Physical activity. 2024. Accessed November 16th, 2024.
3. American Heart Association. American Heart Association Recommendations for Physical Activity in Adults and Kids. Accessed November 16th, 2024.
4. American Heart Association. Target Heart Rates Chart. 2024. Accessed November 16th, 2024.
5. Colberg SR, et al. Physical Activity/Exercise and Diabetes: A Position Statement of the American Diabetes Association. Diabetes Care. 2016;39(11) 2065-2079. doi: 10.2337/dc16-1728.
6. Chimen M, Kennedy A, Nirantharakumar K, Pang TT, Andrews R, Narendran P. What Are The Health Benefits of Physical Activity in Type 1 Diabetes Mellitus?. A literature review. Diabetologia. 2012;55(3):542-51. doi: 10.1007/s00125-011-2403-2.
7. Snowling NJ, Hopkins WG. Effects of Different Modes of Exercise Training on Glucose Control and Risk Factors for Complications in Type 2 Diabetic Patients: A Meta-Analysis. Diabetes Care. 2006;29(11):2518-2527. doi: 10.2337/dc06-1317.
8. Sluik D, et al. Physical Activity and Mortality in Individuals With Diabetes Mellitus: A Prospective Study and Meta-analysis. Arch Intern Med. 2012;172(17):1285-1295. doi: 10.1001/archinternmed.2012.3130.
9. Jelleyman C, et al. The Effects of High-Intensity Interval Training on Glucose Regulation and Insulin Resistance: A Meta-Analysis. Obes Rev. 2015 Nov;16(11):942-961. doi: 10.1111/obr.12317.
10. Whelton PK, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. 2018;71(6):13-115. doi:10.1161/HYP.0000000000000065.
11. Masmoum MD, et al. The Effectiveness of Exercise in Reducing Cardiovascular Risk Factors Among Adults: A Systematic Review and Meta-Analysis. Cureus. 2024;16(9):68928. doi: 10.7759/cureus.68928.
12. Alexander L. How Does Exercise Affect Sleep?. The National Council on Aging. 2024. Accessed November 16th, 2024.
13. National Institute of Health. National Heart, Lung, and Blood Institute. Physical Activity and Your Heart: Benefits. 2022. Accessed November 16th, 2024.

*Information presented on RxTeach does not represent the opinion of any specific company, organization, or team other than the authors themselves. No patient-provider relationship is created.