Dr. Darren Warburton
School of Kinesiology
Dr. Shannon Bredin
School of Kinesiology
Abstract: A risk-benefit paradox applies when considering how much exercise is needed for good health. Vigorous exercise can transiently increase the short-term risk for an adverse event (such as a myocardial infarction or sudden cardiac death); however, participation in routine exercise can also markedly reduce the long-term risk for premature mortality and is an effective primary and secondary preventive measure for more than 25 chronic medical conditions. Active individuals often exhibit risk reductions of 50% or more for mortality and morbidity. An exercise dose-response relationship exists; with the greatest benefits seen when previously inactive individuals become more active. There may, however, be an attenuation of benefit at the extreme end of the exercise continuum (e.g., for ultra-endurance events). Prolonged strenuous exercise training or events have been associated with various risks, including sudden cardiac death, atrial and ventricular arrhythmias, and pathological remodeling of the myocardium. The optimum and minimum amounts of physical activity/exercise needed to achieve health benefits are disputed. Inactive individuals may be discouraged by recommendations for an amount of activity that seems unachievable and is greater than what is required for clinically relevant health benefits, while endurance athletes often exercise at levels and intensities well beyond what is needed to achieve health benefits. Current physical activity guidelines have been widely criticized because they do not include varied types and amounts of activities to address the diverse needs of society. There is strong evidence to support the need for individualized exercise prescriptions for patients, including varied recommendations for improving health-related physical fitness and functional status. Despite the risk-benefit paradox, it is clear that the health benefits of physical activity far outweigh the risks, and virtually everyone can benefit from becoming more physically active.
Read More: http://www.bcmj.org/articles/risk-benefit-paradox-exercise
Warburton, D. E. R., Taunton, J., Bredin, S. S. D., & Isserow, S. (2016). The Risk-Benefit Paradox of Exercise, BC Medical Journal, 58:4, 210–218.
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