How Much Running Is Too Much?
Current exercise guidelines recommend that people get at least 150 minutes of exercise per week. Running is widely considered the best form of exercise for overall health and longevity, because it requires no equipment and improves stamina and cardiovascular health.
Now, I would dispute that– weight training gets your heart rate up, reduces inflammation, and builds muscle which both keeps your metabolism high, preventing creeping weight gain, and helps you maintain mobility as you age. That said, I’m not one of those trainers who thinks resistance training can fully substitute for cardio, and I do believe running has an important place in a balanced health program, even for bodybuilders.
That said, running does have its risks. There is growing evidence that endurance activities like marathons may cause progressive damage to the cardiac muscle over time. One study even found that jogging produces better health outcomes than fast running. In fact, this study found that people who run fast don’t live longer than couch potatoes. I’d take that one with a grain of salt– it’s just one study– but it does show that the evidence doesn’t always support that more exercise is better.
So what gives? How much running is too much, and how hard is too hard?
What Overtraining Is
Overtraining is a state of chronic stress and fatigue that occurs when you overtax your body, exceeding its ability to recover from strenuous exercise.
Contrary to what the name would suggest, overtraining is not purely caused by training too much, or too hard. Rather, overtraining results from a combination of many factors: too much training, too much life stress, lack of sleep, under-eating, illness, and nutrient deficiencies.
In addition to variables like diet and exercise, your propensity for overtraining will depend on training status. As you train more and more, your body both becomes more resistant to training fatigue, and better able to recover from it. Due to these training adaptations, more experienced trainees can train longer and harder-and in fact, need to do so to keep making progress.
Thus, the amount of training that it takes for a person to overtrain is highly variable. A novice trainee with high stress and a poor diet might overtrain if they run 20 miles a week. An experienced trainee who’s doing everything right might be able to run 100 miles a week, and lift weights 4 days a week, without overtraining.
Most experts make a distinction between overreaching- in which a person trains more than is productive, and stops making progress- and overtraining syndrome, in which a person beats themselves up so much that they feel chronically sick and fatigued. It’s not clear that these are really two different conditions, and it seems the difference may simply be a matter of degree. The mechanisms behind overtraining syndrome are still poorly understood.
Evidence for Overtraining in Practice
In my previous article on heat adaptation, I mentioned Alberto Salazar, an Olympic marathon runner who suffered from severe overtraining syndrome for many years. At one time he was one of the best marathon runners in the world, and typically ran about 120 miles a week. When he increased his training load to 180 miles a week- or more- he suffered from severe overtraining syndrome, to the point where he was diagnosed with exercise-induced asthma and bronchitis, and eventually was unable to run even five miles at a stretch.
True overtraining syndrome- in which an athlete feels sick and fatigued for months on end- is rare. However, most athletes do overreach from time to time, training to the point where their progress stalls for weeks at a time. The average athlete suffers from overreaching once every few years, with the average episode lasting around a month.
That said, very mild overreaching isn’t necessarily bad. Some scientists believe that occasional, mild overreaching, followed by a period of light activity and adequate recover, can lead to long-term performance increases. This theory is disputed however, as other studies have suggested that it’s better to avoid overtraining, thereby avoiding the need for time off.
That leads us to the million-dollar question: How much does it take to overtrain?
How Much Top Runners Run Per Week
As previously mentioned, Alberto Salazar ran 120 miles a week when he was one of the best runners in the world. This is typical of world-class endurance athletes.
Boston Marathon winner Des Linden runs 16-18 miles a day, every day, or 112-126 miles a week. She splits this daily training into one long run in the morning, and a shorter, active recovery session in the evening. She also occasionally hits the gym or does yoga. This is her routine when prepping for a marathon; she does go through periods of lighter activity.
Meb Keflezighi, another Boston Marathon winner, reports running about 105-120 miles a week. This includes two or three long runs a week, including an occasional run of longer than marathon length, as well as several speed and interval sessions per week. he also cross-trains by using an elliptical machine and doing daily core strengthening exercises.
In short, the world’s best athletes can run over a hundred miles a week while also mixing in some other training modalities. Most people can’t train that much- but for intermediate-level distance runners, 30-40 miles a week split between 5-6 runs, plus several gym sessions, should be fine as long as you’re recovering well. Newbies might want to start at 10-20 miles a week, split between 3-4 sessions.
Bear in mind, these are soft maximums– you could run a bit more, and you also don’t need to run nearly that much to reap major health benefits. I certainly don’t!
So far though, we’ve only talks about performance. What about longevity?
Run Longer to Live Longer?
It is true that too much running can be bad for your heart, and even runners can still develop heart disease. Sudden cardiac death is even possible, but exceedingly rare.
What about that study showing that people who run “too fast” don’t live longer? The vast majority of studies have reached the opposite conclusion: exercise of any kind is consistently associated with a greater lifespan.
And what about cardiac damage from marathon running? It does happen, but there is some dispute as to whether it truly constitutes “damage” in the sense of being bad for you in the long run, or is merely a training stress that the heart later recovers from, given adequate rest. As always, the dosage makes the poison.
That said, when looking at the life expectancy of elite athletes, endurance athletes like marathon runners consistently live longer than both couch potatoes and strength athletes like powerlifters. It has been suggested that the relatively poor results for strength athletes may be due to anabolic steroid usage. Since resistance training has health benefits that can’t be obtained from running- like improvements in bone density and testosterone levels- it is most likely that optimal health requires a mix of weight training and cardio.
To be clear: while running a hundred miles a week may be alright, it isn’t necessary. To maximize longevity, a few short runs or jogs plus a few gym sessions per week will suffice.
Practical Guidelines for Avoiding Overtraining
How do you know if you’re overtraining? You’ll start to suffer from chronic fatigue. You’ll get sick more often. Subjectively, you’ll feel terrible. Most notably, your progress will come to a halt- maybe even start reversing itself.
The symptoms of overtraining can be hard to distinguish from other things like having a cold, stress or lack of sleep. The best way to know for sure is to experiment. If you perform better after taking a couple of days off, that’s the surest sign that your body could use more rest than it’s getting.
Ultimately, you need to listen to your body, and you need to auto-regulate your training, adjusting the workload to match your recovery capacity. When you notice your progress slowing down, and training makes you more tired than it used to, it’s time to dial back the volume and intensity a bit. After one to four weeks of lighter workouts, you’ll be back to normal and ready to push yourself again.