Exercise: A Two Edged Sword

It has been well engrained in our psych by years of emphasis by doctors that exercise is always good and more the better. It is no doubt, there is abundance of evidence in the medical literature to support such understanding. But lately data have been pouring in to point out the risks associated with heavy and intense exercise. Basically what the data shows is that at a certain optimum level human body attains a plateau for the good efforts of exercise especially on the cardiovascular system. Beyond this level the exercise pushes one into the domain of optimum risks and increase the chances of death. Even at a moderate exercise level the risk of sudden cardiac death increases a little and lasts for one hour afterwards. Yet the moderate exercise protects against death for the other 23 hours of no exercise. So in the long range one who exercises regularly comes out a winner. The inherent minor risk with any moderate level of exercise does of course get augmented if the intensity is increased.

A paper published in the journal “HEART” in 2014 by Dr. Ute Mons and collegues from the German Cancer Center, showed that the risk of cardiovascular death decreases with moderate exercise in patients who otherwise rarely or never exercise. However they also showed that the risk of death was higher in those who exercised daily than for those who exercised only for two to four times per week. This is shown in the diagram below. Another study published in the journal. Mayo Proceedings reinforced similar results in a focused group of patients who survived a heart attack. It showed that those patients from this group who took a brisk walk average 6.6 miles per day increased their risk of death more than three times.

A study published from Oxford university in the journal Circulation in February 2015 which examined the life-style habits of one million women showed very clearly that the risk of heart attack and stroke decreased 20% in those who exercised vigorously three times or more per week and the risk increased in those who exercised more vigorously and more frequently.

Based upon the above clearly defined evidence physicians now understand the risks/benefits pendulum oscillates between two extremes. While sedentary lifestyle definitely increases cardiovascular risk of stroke, heart attack and death, the other extreme at increasing levels of exercise also increases risks proportionately. The happy medium of moderate exercise like walking brisk for 2 miles, or its equivalent in bicycling or any other form, 2 to 3 times a week definitely is protective and beneficial. It reduces the risk of heart attack, stroke and death. The American Heart Association and American College of Cardiology guidelines written by Robert H. Eckel M.D. professor of cardiology at the University of Colorado, Denver and collegues even define the optimal duration of exercise for laymen to understand. It is 150 minutes per week of moderate exercise or 75 minutes per week of more than moderate exercise. In an interview Dr. Eckel emphasized that one should begin spending 10 to 15 minutes a day walking brisk. This is modest and can be put into even busy schedule. From there gradual increases in the physical activity are recommended as tolerated until a level of maximum benefit achieved.

From a recent cover story of the journal Cardiolog Today, here are some of the quotes from renowned physicians to further reinforce this understanding.

“My advice for sedentary patients s to do something, go for a walk even just 5 to 10 minutes at a time. It doesn’t take much…… to see a difference.”

Michael J. Joyner M.D. Professor of anesthesiology at Mayo Clinic, Rochester, Minnesota


“With general encouragement, you want to get people to lose the habit of sitting and adopt the habit of moving.”

John Swartzberg M.D. FACP Professor of Public Health, University of California, Berkeley.


“From a health perspective, you don’t need to do extreme exercise to gain all the cardiovascular”… to be continued…