The Centers for Disease Control, American College of Sports Medicine (ACSM), American Heart Association, and The Fitness Doctor recommend >5 days of week of moderate (or >3 days per week vigorous) cardiorespiratory (aerobic) exercise per week to improve fitness and reduce risk of illness and disease. Specifically, this dosage of exercise has been shown to reduce all cause mortality and reduce the risk of developing coronary heart disease, stroke, type 2 diabetes, and cancer.
Also of note is the positive impact of exercise on our mental health including prevention/improvement of anxiety, depression, and other psychological disorders, as well as, improvement in quality of life and a lower risk of cognitive decline and and dementia.
WHAT IS THE RISK?
Musculoskeletal injury is the most common risk associated with exercise, but a cardiovascular event (i.e. myocardial infarct) is much more serious. Prior research has demonstrated a risk of an acute myocardial infarction with vigorous aerobic exercise (jogging) particularly among individuals with underlying heart disease, often without signs and symptoms, or among those who initiate vigorous exercise from a sedentary lifestyle.
In younger individuals, <30 in males and <40 in females, the underlying cause of cardiovascular injury is likely congenital in nature (heart defect, arrhythmia). Fortunately, these events in younger individuals are rare (approximately 1 event in 133,000 and 769,000 men and women), respectively.
Risk Factors
AGE: Man > 45 | Woman > 55
FAMILY HISTORY: Myocardial Infarction, coronary revascularization, or sudden death before 55 in father (or other 1st degree male relative) or 65 in mother (or other 1st degree female relative)
SMOKING: Current smoker (or quit less than 6 months ago)
PHYSICAL INACTIVITY: Not being active (70% of HRmax) for at least 3 days per week for at least the last 3 months
BMI: <30 | Waist size: > 40 for men (> 35 in women)
HYPERTENSION: >140/>90
DYSLIPIDEMIA: LDL > 130 | HDL < 40| Total Cholesterol > 200
DIABETES: Fasting glucose > 126 | 2 hr glucose >200 | HBA1C >6.5%
The American Heart Association recommends cardiovascular screening for high school and college age individuals at 2 and 4 year intervals or more frequently for individuals with known disease. As we age our risk for cardiovascular events (males > females) with exercise increases, regardless of other risk factors such as smoking and high blood pressure. Population data reports a yearly incidence of 1 acute cardiovascular event in between 500 to 3900 adults each year . This incidence increases substantially in individuals with known cardiovascular disease and prior history of events with exercise.
In trained individuals meeting the cardiovascular standards reported above the relative risk of an acute cardiovascular event decreases substantially to approximately 1/10th that of a sedentary individual . It is clear from the literature and guidelines individuals must determine their risk of injury and illness with aerobic exercise and adjust their exercise volume appropriately. In Table 1 below, risk factors for exercise are defined for a group of modifiable and non-modifiable categories. In addition, a HDL level above 60 mg/dl is considered a negative risk factor and reduces risk for events with exercise.
Every active individual should identify how many risk factors they have in order to gauge their risk for a cardiovascular event with exercise. For example, a 46 year old male with high blood pressure (or taking high blood pressure medication) has two risk factors. In Table 2 we can determine the American College of Sports Medicine Risk Level based on this total score.
As you can see, men over 45 (and women over 55) are at moderate risk for injury irrespective of their health or risk factors.
In closing, an appropriate exercise prescription may be one of the most powerful weapons to ward of disease, illness, and physical and cognitive decline with exercise. As we strive to reach the thresholds associated with these benefits, we must understand how to mitigate any risk associated with this training.
Before starting any physical activity program, I strongly suggest contacting your medical doctor. If you are concerned about your risk, feel free to schedule a consultation with me directly! https://www.thefitnessdoctors.com/book-online