Why Exercise Will Save Your Life: A Review of Medical Literature.
Conclusions and recommendations from recent medical literature publications:
- Cardiorespiratory fitness is as strong a predictor of mortality and death, above and beyond established risk factors such as cigarette smoking, high blood pressure, high cholesterol and diabetes.
- A Cardiorespiratory fitness level of less than 5 metabolic equivalents (METs) in adults is associated with a high risk for mortality and death; Cardiorespiratory fitness levels greater than 8 to 10 METs are associated with increased survival.
- More than half the reduction in all-cause mortality and death occurs between the least fit (eg, CRF <5 METs) group and the next least fit group (eg, CRF 5–7 METs).
- Small increases in Cardiorespiratory fitness (eg, 1–2 METs) are associated with considerably (10% to 30%) lower adverse cardiovascular event rates.
- Adults should do at least 150 minutes to 300 minutes a week of moderate intensity, or 75 minutes to 150 minutes a week of vigorous intensity aerobic physical activity.
Exercise is essential and vital for health. Growing research and medical literature are supporting the vital role that exercise has in our lives. Medical literature refers to being “fit” as having a strong and robust cardiorespiratory capacity. Cardiorespiratory fitness (CRF) refers to the capacity of the circulatory (heart and blood vessels) and respiratory (lungs and breathing structures) systems to supply oxygen to skeletal muscle mitochondria for energy production needed during physical activity. Mitochondria are a part of human cells that are in charge of creating energy for cells to function and continue their job.
A consistent finding in medical literature exercise studies is that cardiorespiratory fitness is a strong and independent marker of risk for cardiovascular disease, mental health, all-cause mortality and death. These observations have been made in healthy men and women, those with suspected or known cardiovascular disease, and those with comorbid conditions, including obesity, Type II diabetes, hypertension, and lipid abnormalities. In a growing number of studies, cardiorespiratory fitness has been demonstrated to be a more powerful predictor of mortality or death risk than traditional risk factors such as hypertension, smoking, obesity, hyperlipidemia, and Type II diabetes. These are significant findings that make exercise and cardiovascular fitness an enormous priority in one’s health. It’s crucial to exercise and improve cardiovascular fitness, so that one can stay healthy and live longer.
Some benefits of physical activity can be achieved immediately, such as reduced feelings of anxiety, reduced blood pressure, improvements in sleep, positive effects on some aspects of cognitive function and insulin sensitivity. Other benefits, such as increased cardiorespiratory fitness, increased muscular strength, decreases in depressive symptoms, and sustained reduction in blood pressure, require a few weeks or months of participation in physical activity. Physical activity can also slow or delay the progression of chronic diseases, such as hypertension and type 2 diabetes. See Table 2-1. Benefits persist with continued physical activity. As a primary care sports medicine physician, Dr. Kevin Mangum has completed extensive training in advising patients in regards to exercise, and creating exercise prescriptions to assist patients with health and longevity.
Some of the benefits of physical activity on brain and mental health occur immediately after just one session of moderate-to-vigorous physical activity (acute effect), such as reduced feelings of state anxiety (short-term anxiety), improved sleep, and improved aspects of cognitive function. With regular physical activity (habitual effect), improvements are seen in trait anxiety (long-term anxiety), deep sleep, and components of executive function (including the ability to plan and organize; monitor, inhibit, or facilitate behaviors; initiate tasks; and control emotions). Table 2-3 describes the benefits of physical activity for brain and mental health.
In many studies, cardiovascular fitness is measured by complicated formulas and tests. In order to simplify cardiovascular fitness, some studies convert cardiovascular fitness into metabolic equivalents (METs). One MET is defined as the resting metabolic rate, that is, the amount of oxygen consumed at rest, sitting quietly in a chair. This equates to approximately 3.5 ml 02/kg/min (1.2 kcal/min for a 70-kg person). As such, work at 2 METS requires twice the resting metabolism or 7.0 ml O2/kg/min and three METS requires three times the resting metabolism (10.5 ml 02/kg/min), and so on.
Here is a list of activities and their associated METs:
When exercise is performed frequently over weeks or months, a wide variety of endurance-type physical activity regimens produce clinically significant increases in CRF (ie, ≥1 MET) in most adults. In general, the greater the activity amount or intensity, the greater the increase in CRF. Increases in CRF appear more responsive to increases in intensity than increases in session duration or frequency.
Work intensity is a most important factor in the establishment of a conditioning or rehabilitation exercise pro- gram. For aerobic training, a proper dosage of exercise is considered to vary from 40% of maximum METS for poorly conditioned and/or symptomatic persons to perhaps 85 % of maximum METS for well-conditioned athletic persons. A training intensity of 60-70% of maximum METS, the average level of anaerobic threshold, is typically prescribed for most healthy, asymptomatic individuals when performing continuous aerobic training. Balke recommends the following sliding scale for prescribing an acceptable training intensity: Training Intensity = [(60 + Max METs)/100] X Max METs.
Light-intensity activities, like non-sedentary walking, require less than 3.0 METs; examples include walking at a slow or leisurely pace (2 mph or less), cooking activities, or light household chores. Moderate-intensity activities require 3.0 to less than 6.0 METs; examples include walking briskly (2.5 to 4 mph), playing doubles tennis, or raking the yard. Vigorous-intensity activities require 6.0 or more METs; examples include jogging, running, carrying heavy groceries or other loads upstairs, shoveling snow, or participating in a strenuous fitness class. Many adults do not engage in vigorous-intensity physical activity unintentionally.
To simplify the exercise equations and exercise prescription, the CDC has published these recommendations. For substantial health benefits, adults should do at least 150 minutes (2 hours and 30 minutes) to 300 minutes (5 hours) a week of moderate intensity, or 75 minutes (1 hour and 15 minutes) to 150 minutes (2 hours and 30 minutes) a week of vigorous intensity aerobic physical activity, or an equivalent combination of moderate and vigorous intensity aerobic activity.
If you have questions about how you can improve your physical activity with your specific medical conditions, please make an appointment with the sports medicine physician Dr. Kevin Mangum to discuss appropriate modifications that can help you to optimize your physical activity and health.
Ross, Robert, et al. “Importance of assessing cardiorespiratory fitness in clinical practice: a case for fitness as a clinical vital sign: a scientific statement from the American Heart Association.” Circulation 134.24 (2016): e653-e699.
Kodama, Satoru, et al. “Cardiorespiratory fitness as a quantitative predictor of all-cause mortality and cardiovascular events in healthy men and women: a meta-analysis.” Jama 301.19 (2009): 2024-2035.