In the barefoot running world, we CONSTANTLY talk about the idea of listening to your body. This is a more palatable way of saying “If it hurts, stop or do something else.”
The same concept applies to ultrarunning. If you're doing something that causes pain, you're probably doing it wrong. Learn to listen to the signals your body gives, then adjust accordingly.
Of course, there's a serious problem with this advice. Running really long distances hurts. A lot. I'll give you some tips to deal with the pain later on, but it does leave us with the question- how do you know if it's “I'm injured” pain or “This is just normal pain everybody experiences when running ultras”?
The question is difficult to answer. Experience will teach you the difference. But what do you do in the interim? Follow these tips:
Here's my annoying disclaimer: I'm not a medical professional, and I'd recommend consulting one before doing any of this.
1. Generally speaking, muscle soreness is okay. If you've ever lifted weights, it's that feeling you have when you first started. Never felt that? Here's a demo. Do 100 pushups as quickly as possible. Pause to rest if needed, but the quicker the better. That burning you feel? That's usually okay. Stop reading and come back tomorrow.
[one day later]
Feel that soreness in your pecs? That pain is okay, too.
2. Sharp shooting pains are generally bad. If it feels like someone is impaling you with a burning hot fireplace poker. You should stop. Rest until the pain subsides, seek medical attention if needed.
3. If you experience dull aches hours or a day after a workout, that could be bad. Rest until the pain subsides, seek medical attention if needed.
4. If you experience any weird sensations or symptoms like discoloration, pain that isn't muscular, chest pain, light-headedness, abnormal swelling, fever, weight gain, or anything else abnormal, seek immediate medical attention. Always better to be safe than sorry. and there's always a chance the ambulance driver/nurse/doctor will be hot.