As is custom at the start of a new year, many people resolved to sit around less and exercise more. In light of the global pandemic, this is as great an idea as ever, according to Arthur Weltman and Siddhartha Angadi, kinesiology professors in the University of Virginia’s School of Education and Human Development
“We know that being physically active and exercising regularly, as well as reducing sedentary behavior, are among the best things an individual can do to improve their health, quality of life and overall well-being,” Weltman said.
UVA Today caught up with Weltman and Angadi to learn, among many things, just how much exercise is the right amount to be of benefit, and how to safely return to pre-sickness exercise regimens after you’ve contracted COVID.
Q. In general, what are the benefits of regular physical activity?
AW: They include and are not limited to: reduced risk of all-cause mortality; reduced risk of developing coronary heart disease, stroke, multiple forms of cancer, type 2 diabetes, obesity, hypertension and osteoporosis; improved functional capacity, quality of life and ability to engage in activities of daily living; improved brain health and conditions that affect cognition, including depression, anxiety, dementia and Alzheimer’s disease; reduced risk of falls and fall-related injuries; and improved sleep.
Exercise is also an effective treatment for a variety of chronic diseases – oftentimes more effective than prescription medication – and comes with fewer side effects. Exercise that improves physical fitness – particularly cardiovascular and muscular fitness – conveys additional health-related benefits.
Q. What are the current recommended levels of physical activity needed to achieve these health benefits?
SA: They are 150 minutes per week of moderate intensity or 75 minutes per week of vigorous intensity activity (or an equivalent combination) and two or more days a week of muscle strengthening activities that work all major muscle groups – legs, hips, back, abdomen, chest, shoulders and arms. If you go beyond these basic recommendations, you will gain even more health benefits.
Q. How do you define sedentary behavior, and what are the risks?
AW: Sedentary behavior can be defined as any waking behavior associated with low levels of energy expenditure. For example, sitting, reclining or lying down.
The 2018 Physical Activity guidelines defined sedentary behavior to include sitting – leisure and/or occupational – television viewing or screen time, or low level of measured movement. Sedentary behavior independently increases the risk of all-cause mortality, cardiovascular disease and cardiovascular disease mortality, type 2 diabetes and certain forms of cancer.
Risk of All-Cause Mortality in Adults
SA: The heat map above is taken from the 2018 Physical Activity Guidelines (Figure 1-3). The vertical axis depicts sedentary behavior, and the horizontal axis depicts moderate to vigorous activity. As you can see, those who have a high amount of sitting time with low levels of moderate-vigorous physical activity (MVPA, top left corner) have the highest risk of all-cause mortality, whereas those with little daily sitting time and a high amount of MVPA have the lowest risk of all-cause mortality (lower right corner).
However, their findings suggest that even in those with high amounts of sitting time, the risk of all-cause mortality decreases as MVPA increases (top left to right) and at the highest levels of MVPA the risk of all-cause mortality is low, regardless of sitting time (top right). The current estimate for the volume of daily physical activity needed to lower risk is 60 to 75 minutes of moderate intensity or 30 to 40 minutes of vigorous-intensity activities.
Q. How does regular physical activity and exercise – if at all – impact the severity of COVID-19 symptoms?
AW: We want to state unequivocally that regular exercise is not a substitute for scientifically accepted preventive measures – vaccination, masking, social distancing.
That said, these were the results of the most comprehensive report to date by Robert Sallis and his colleagues, who identified 48,440 adult patients with a COVID-19 diagnosis from Jan. 1, 2020 to Oct. 21, 2020, who had at least three exercise vital sign measurements between March 19, 2018 and March 18, 2020.
- Patients with COVID-19 who were consistently inactive during the two years preceding the pandemic were more likely to be hospitalized, admitted to the intensive care unit and die than patients who were consistently meeting physical activity guidelines.
- Other than advanced age and a history of organ transplant, physical inactivity was the strongest risk factor for severe COVID-19 outcomes.
- Meeting U.S. Physical Activity Guidelines was associated with substantial benefit, but even those doing some physical activity had lower risks for severe COVID-19 outcomes, including death, than those who were consistently inactive.
Q. Did the authors have any recommended suggestions for the future?
AW: The potential for habitual physical activity to lower COVID-19 illness severity should be promoted by the medical community and public health agencies. And pandemic control recommendations should include regular physical activity across all population groups.
It should be noted that meeting activity guidelines does not lower transmission rates of COVID-19; it only appears to reduce severity of symptoms associated with the virus. Many individuals who exercise regularly will contract COVID-19 (particularly the highly contagious omicron variant) with a wide variety of symptoms associated with the virus.
Q. If you’ve contracted COVID-19 and want to try and get back into exercise, is there a recommended approach to doing so?
SA: Since COVID-19 often affects multiple systems, such as the lungs, heart and kidneys, a graduated return to play or exercise is recommended. This primarily applies to those that have a mild or moderate case of the illness, which is typically observed in vaccinated and boosted individuals and has special relevance given the current omicron outbreak.
For those with complicated infections requiring hospital support, medical assessments including testing of cardiac injury biomarkers, along with assessment of pulmonary function, EKG, exercise treadmill testing and/or cardiac MRI are often indicated prior to return to physical activity.
AW: Before considering a return to exercise, it’s important that the individual has been symptom-free for at least seven days and can walk about 500 meters (0.3 miles) on a flat surface without excessive feelings of fatigue or breathlessness.
The recommended way to return to your baseline level of exercise is to take it slowly in stages. It’s recommended that you spend a minimum of seven days in each phase. Ratings of perceived exertion – how hard you feel you are exercising or working to carry out a given activity – can be used to guide choice of exercise intensity. The scale below depicts the rating of perceived exertion scale. A 6 on the scale corresponds to no exertion at all, while 20 corresponds to maximal effort.
|Little to no movement, very relaxed
|Able to maintain pace
|Comfortable and breathing harder
|Minimal sweating, can talk easily
|Slight breathlessness, can talk
|Increased sweating, still able to hold conversation but with some difficulty
|Sweating, able to push and still maintain proper form
|Can keep a fast pace for a short time period
|Difficulty breathing, near muscle exhaustion
|STOP exercising, total exhaustion
Phase 1: Flexibility, stretching, walking at an RPE of 6-8.
Phase 2: Low-intensity activity, such as walking or yoga. Build up your time walking in 10- to 15-minute increments per day. RPE 6-11. The goal is to get up to 30 minutes of walking per day at an RPE of 11.
Phase 3: Moderate-intensity aerobic exercise (and you can add on some resistance training) at an RPE of 12-14. The goal is to make sure you get to 30 minutes per day and feel recovered within an hour after exercise. You can add one 5- to 10-minute interval per day as tolerated. One day of exercise should be interspersed with one day of recovery.
Phase 4: You can move up to two days of exercise with one day of recovery. RPE Intensity same as in Phase 3.
Phase 5: You should be able to get up to your baseline level of exercise in phase 5. Exercise intensity can be ramped up to an RPE above 15 as tolerated.
Make sure you keep the following in mind when going through these phases: Spend a minimum of seven days per phase. Only exercise if you feel like you have recovered from the previous day and are having no new symptoms. Make sure to spend a few minutes warming up and cooling down. If, at any point during exercise, you feel an abnormal shortness of breath or chest pain, seek medical advice.
Those individuals with co-morbidities, such as a history of diabetes, cardiovascular or renal disease, should undergo a medical assessment prior to commencing intense exercise.