Overtraining in Runners: Signs, Causes and How to Avoid It
Overtraining is what happens when your training load exceeds your ability to recover for too long. It goes well beyond a bad day or a hard week: it is a state in which you perform worse even when you rest, you feel exhausted and it takes weeks or months to feel well again. Luckily, it almost always gives warning signs and can be avoided. In this guide I explain the difference between normal fatigue and overtraining, the signs to watch for, why it happens and what to do if you think you have it.
Normal fatigue, overreaching and overtraining
Training makes you tired, and that is normal. A hard week leaves you fatigued for a few days and, after resting, you perform better than before. That is called functional overreaching, and it is exactly what you are after.
The problem comes when you pile up load without recovering. First comes non-functional overreaching: you have been tired for weeks and your performance stalls or drops, although a few weeks of rest bring you back. If you keep pushing, you can reach overtraining syndrome, where recovery takes months. That is how the European and American consensus statement on overtraining syndrome describes it.
Signs of overtraining
The clearest sign is performance that keeps dropping even when you rest: paces that used to be easy become hard and intervals don’t go well. Other signs add to that.
Fatigue that doesn’t go away after a couple of rest days. A higher resting heart rate and lower HRV for days, as I explain in the guide on resting heart rate. Trouble sleeping, irritability, no motivation to train or low mood. Loss of appetite. Frequent colds and aches or injuries that never quite heal. In women, changes in or loss of periods, which should always be checked with a doctor.
Why overtraining happens
It is almost never just from training a lot. It is usually several things added together: increasing volume or intensity too quickly, doing too many hard sessions in a row, sleeping too little, eating less than you burn and stress from work or personal life.
Under-eating deserves a special mention. If for weeks you take in less energy than you need, your body starts saving and fatigue, injuries and hormonal problems appear. It is a common problem among runners trying to lose weight while training hard.
How to prevent overtraining
Build your load gradually and include an easier week every three or four. Keep most of your kilometers easy and don’t stack hard sessions, as I explain in the guides on how to train in zone 2 and how many days a week to run.
Sleep seven to nine hours, eat enough, with carbs around your sessions, and take the stress of the rest of your life into account: a tough week at work is also load. And watch the early signs, like your resting heart rate or bad feelings that keep repeating.
What to do if you think you are overtrained
The first thing is to stop or cut your load a lot. If it is only overreaching, a few days or a couple of weeks of very easy runs or rest are usually enough. If the symptoms are strong or last longer, see a doctor: other causes with similar symptoms, like anemia, thyroid problems or infections, should be ruled out.
Your return has to be gradual, starting with short, easy runs and building up slowly, with no intervals until the fatigue is gone. There is a similar guide on getting back into running after a break. And look at what got you there, so you don’t repeat it.
Conclusion
Overtraining is a sustained imbalance between load and recovery that makes you perform worse even when you rest. Watch for the signs: dropping performance, fatigue that won’t go away, high resting heart rate, poor sleep and frequent colds. Preventing it is easier than fixing it: gradual load, easy days kept easy, good sleep, eating enough and lighter weeks. Choose well, run better.
Frequently asked questions
What are the symptoms of overtraining?
Performance that drops and doesn’t improve with rest, persistent fatigue, high resting heart rate, sleep problems, irritability, loss of appetite, frequent colds and injuries that don’t heal.
How long does it take to recover from overtraining?
Overreaching recovers in days or a few weeks. Overtraining syndrome can take months, which is why spotting it early matters so much.
How do I know if I am tired or overtrained?
If two or three rest days make you feel good again, it is normal fatigue. If you are still exhausted and performing worse after resting, it may be overreaching or overtraining.
Can under-eating cause overtraining?
Yes. Taking in less energy than you burn for weeks increases fatigue, injury risk and hormonal problems, and it is a common cause in runners.
What should I do if I think I am overtrained?
Cut your load a lot or rest, sleep and eat well, and see a doctor if the symptoms are strong or last more than a couple of weeks. Return to training gradually.
