Sometimes it's easy to know when to call it quits, but other times bailing on a run or race can be a tough decision. Not finishing a run (a.k.a. a DNF or "Did Not Finish") can feel like a tough blow, but sometimes it can actually benefit you in the long term. The next time you consider a DNF, suss out the cause and then try to make an informed decision.
If you want to DNF due to external circumstances...
A common (and very understandable!) reason for bailing on a run is the weather. However, there's not always a clear-cut answer about whether you should call it quits or persevere. If conditions are dangerous (e.g. thunderstorms, icy roads, bad air quality), it's definitely safer to end the run and try again another day (or inside). If the weather is a bit too hot, too cold or too...anything, consider modifying your workout before giving up completely.
For example, if you planned on a PR attempt but race day is during a heat wave, it's probably OK to still run for fun, but you'll need to modify your pace. Likewise, if you're in the middle of a tempo run and you encounter a brutal headwind, consider backing off your pace or transitioning into an easy run instead. Above all else, use common sense when it comes to safety. If conditions feel dangerous, it's better to DNF and stay safe for tomorrow's attempt.
If you want to DNF due to physical issues...
An injury or illness is likely the most common reason for a DNF, but of course there's always special considerations. An acute injury that's very painful (e.g. a torn muscle or a suspected stress fracture) is a one-way ticket to a DNF.
But what about a chronic ache like a sore IT band? Or how about congestion and a runny nose? It will likely depend on your goal for the day. Is this a once-in-a-lifetime event like a major marathon? If so, you might consider packing some tissues and enjoying the experience. However, if it's a training run, it's probably smarter to take it easy and save the miles for another day. If physical issues crop up once in awhile, it's no biggie, but if you're constantly bailing on runs or races due to injury or illness, it might be time to take a deeper look at your lifestyle and training habits.
If you want to DNF because your mental game is struggling...
The final category is probably the murkiest. What if the weather is great and your body is cooperating and...you still want to DNF? It's important to ask yourself why you're feeling low. Are you going through a stressful time (i.e. a major life change)? Or are you just having a bad day? If it's the former, it's a good idea to cut yourself some slack. If it's the latter, try adding in some walk breaks (or switching to walking completely). If you're feeling blah, take the pressure off and just focus on breaking a sweat.
Of course, if your lack of focus is due to overtraining, that's a good sign it's time to take a longer break from running. If the feeling persists, a coach can help you figure out what's going on.
If you're like most runners, the goal is to run for a lifetime. So remember that bailing on one race or training run is simply a blip on the radar.
READ THIS NEXT: How to Adjust Your Race Goals in Less-Than-Ideal Conditions