A while back, Medical Daily published an article suggesting that more than 50 minutes of endurance exercise “may lead to early death” due to overexertion of the heart. While I understand that writers are pressured by the need for a good headliner, the notion that longer duration exercise is hazardous to heart health is both inaccurate and misleading. This article is burdened by two misinterpretations and I’ll address both.
First off, the writer misinterpreted an editorial written by clinicians who used the results of two separate studies to back their claim that “extreme endurance exercise” may pose a threat to cardiovascular health.
The studies discussed involved runners and joggers. That’s it! Herein lines the first issue, overgeneralizing. Are running and jogging the only forms of endurance exercise? Absolutely not as the list of endurance exercise types is virtually endless—walking, bicycling, stair climbing, elliptical treading, hiking, basketball, volleyball, racquet sports, group fitness, etc. Furthermore, those of us who exercise on a regular basis may perform these exercise for hours a day.
Does this mean we’re at risk?
More than likely this is not the case.
Findings from a study inclusive of only joggers and runners is biased and cannot be generalized to all types of endurance exercise.
The second problem is the writer only pointing out the fact that individuals in these studies who “ran more quickly” were at increased risk when compared to those who “ran at a comfortable speed at about six to seven miles per hour.”
How does this connect to the health risks associated with 50-plus minutes of endurance exercise?
Truth is, the ‘Average Joe’ who calls himself a ‘runner’ is actually a jogger because, on average, most people who ‘run’ pace themselves somewhere between five and six miles an hour. Furthermore, it’s walking (not running) that’s the most popular form of endurance exercise these days and there is ample evidence that walking for prolonged periods of time offers cardiovascular protection.
In light of these facts, I would dare say that the general population is not at risk of ‘early death’ from longer duration exercise.
Now, here’s the science behind the misinterpretations I’ve highlighted.
Exercise intensity is inversely related to duration, which essentially means that exercises performed at a higher intensity (high-speed running) should be performed for shorter periods of time while low-to-moderate intensities of exercise (walking and jogging) can be performed for longer periods of time.
Excessive amounts of high-intensity exercise can impair vascular function (a precursor to heart disease), which is why we as exercise scientists generally don’t recommend prolonged exposure to high-intensity exercise bouts. When viewed in the lens of the science, now suddenly the misinterpreted results make since right? It’s not that too much time spent exercising is a problem, it’s that too much high-intensity exercise may present issues in the long-term.
So, don’t be discouraged from taking your 5-mile walk because it takes you well over 50 minutes to finish. Don’t stop enjoying your 2-hour tennis games either. You won’t be checking out of here any time soon as a result of such exercise habits. At the same time, if you prefer to engage in higher intensities of exercise, don’t fret. Just alternate your high-intensity workouts with those of low-to-moderate intensity and you’ll be just fine.