In the running world, we always think of running as an unequivocally good thing. After all, it is good exercise, so it cannot be harmful, right? Not quite true. There is new medical evidence to suggest that it might be harmful to do too much running. Overworking the heart and arteries could lead to a shorter lifespan than if you hadn’t run at all.
It is pretty clear that the human body is well-adapted for running. From an evolutionary perspective, running is a crucial skill for humans. It allowed them to hunt down prey and track it over long distances.
Running makes use of the whole body, and the human body has a natural and clean running motion. Just from your own experiences, you have probably noticed people who were totally inexperienced being able to develop good running form without much time or effort. It certainly seems like running is in our blood or our genes.
However, just as lifting too much weight can be dangerous and risks both short and long-term injury, cardiovascular exercise—like running—might be dangerous in excess. A new scientific report in the Journal of the American College of Cardiology examined people who did not exercise at all, people who jogged regularly, and people who ran often and at high speeds. Their results were surprising.
The joggers tended to live the longest of the three groups, and the people who did not run at all and the people who ran a lot tended to die at about equal rates. In other words, running a lot was just as unhealthy as not running at all.
The study tracked more than a thousand people through 12 years of their lives. The three main groups were people who never ran, people who jogged for up to two and a half hours a week, and people who ran at a faster pace for more than four hours every week.
The study suggests that the best rate of speed for healthy running is about 8 km per hour, or about 5 miles per hour. Two and a half hours a day is the upper limit on how much people should jog, according to the authors. Jogging at faster speeds and for longer durations was associated with earlier death.
It is not yet clear why running too much might lead to dying earlier. So far, most of the scientific research into running in particular and exercise in general has been about the health benefits, not the risks. With obesity rates continuing to rise around the world, it seems counter-intuitive to examine the downsides to exercise.
It feels like we should be encouraging more people to run, not telling them that running could be dangerous to their health.
However, that very fact means that people could be running large risks by running too much and not knowing about it. Furthermore, the lack of awareness means that while people who do not exercise are generally self-aware enough to know that they are not making a healthy choice, people who run too much might mistakenly think that they are actually doing something healthy when they are not.
Implications for You
So what does this mean for you, a runner? Think carefully about how much you run and how fast you go. Training for marathons year-round certainly falls into the category of running too much. If you are at that level, or you run for more than four hours a week, it might be a good idea to think about cutting back.
This is especially true if you are doing it for health reasons. Over-running is just as harmful as not running at all, so make sure that you are in the healthy range for running. Think about turning down your speed or spending fewer hours running.
That will also reduce your risk of running injuries, so it has multiple benefits. Over-running is just like over-training for any other sport—by putting more stress on your body, you risk injuries.
These scientific findings are relatively new. There is not enough evidence to conclusively say that too much running is definitely harmful yet. It is always possible that this one study was flawed in some way, and its conclusions are not true. However, it should certainly be cause for concern.
To Run or Not to Run
How do you feel about how much you should run? Do you feel there is a point where you can run too much? Think about the people you know who run the most. Do you think they are over-running? Anecdotes are not the same as scientific data, but they can be illustrative all the same.
You and your friends could be running too much without even thinking about it, and that could have potentially deadly consequences.
You don’t need to cut back on running right away, but have a serious conversation about it and do some research. You might be surprised by what you find.