How to Tell If a Running Pain is Serious or Just Normal Discomfort
If you’re looking to reduce injury risk while running, it’s important to differentiate pain vs discomfort.
As runners, we know that some level of discomfort is part of the sport. Whether it’s the burning in our quads during a tough hill repeat, the soreness after a long run, or the stiffness that greets us in the morning, running isn’t always pain-free. But how do you know when that discomfort is normal and when it’s a sign of a real problem?
As a Doctor of Physical Therapy specializing in running injuries, I help runners navigate this fine line during my coaching and return to run programs. Let’s break it down so you can run with confidence and avoid unnecessary injuries…
Understanding Normal Discomfort vs. Injury Pain
Discomfort is a natural response to training stress, but pain is a warning sign that something may be wrong. Remember that running is not an “all or nothing” sport - there are always modifications that can be made to your program to keep you active!
Normal Running Discomfort:
Muscle fatigue and soreness: Feeling tired or sore after a hard workout, especially 24-48 hours later, is normal and expected. This is called Delayed Onset Muscle Soreness (DOMS), and it’s a sign that your muscles are adapting to training stress.
Mild tightness or stiffness: Experiencing some stiffness when you first start a run but loosening up after a warm-up is typical, especially in colder weather or after a previous hard session.
Burning or fatigue during a workout: A burning sensation in your muscles during intense efforts is a normal response to lactate buildup. It should subside when you slow down or stop.
Warning Signs of Injury:
Pain that alters your running form: If you find yourself limping, favoring one side, or adjusting your stride to avoid pain, that’s a red flag.
Pain that doesn’t warm up: If your discomfort doesn’t improve after 10-15 minutes of running or worsens as you go, it could indicate an underlying issue.
Sharp, stabbing, or localized pain: Unlike general muscle fatigue, sharp or pinpoint pain is more likely to be due to tissue damage, such as a stress reaction or tendon irritation.
Pain that persists after you stop running: Normal discomfort should fade with rest. If pain lingers for hours or days after your run, it’s a sign that something more serious is going on.
Swelling, redness, or warmth: These are signs of inflammation and should not be ignored. Especially if they appear suddenly!
Pain that wakes you up at night or is present at rest: Persistent pain even when you're not active suggests a more serious injury that needs medical attention.
When to Push Through & When to Modify
It can be frustrating to take time off, and in most cases I find that my runners do well with modification of their running. I rarely recommend a full stop to a run training program.
✅ It’s Okay to Keep Running If:
The discomfort is mild and doesn’t worsen as you run.
The pain disappears after a proper warm-up.
It doesn’t affect your running form.
It’s general muscle soreness rather than joint or bone pain.
❌ You Should Modify If:
Pain alters your stride or running mechanics.
The pain increases as you continue running.
It persists after your workout and into the next day.
There is swelling, redness, or significant tenderness in one spot.
The next step is being aware of the intensity of your pain. Rating it on a scale of 1-10 (10 being the highest pain), this chart may help guide you. Or, if rating it is challenging, ask yourself if it is “light”, “moderate” or “intense” pain.
(Created from Silbernagel et al 2007)
Pain that you rate as 1-3 out of 10 is considered safe to keep running with, although at this point you should be considering what exercises you can do to address the issue.
Pain that is 3-5 out of 10 is considered acceptable, but at this point you should be modifying your program and not increasing distance or intensity. In fact, if I’m working with someone reporting pain at this level, often I’ll prescribe a walk/run program.
Pain that is 5+ is risky, and you should stop and seek care.
Modify, Don’t Take Away
Pain is no stranger to runners, but it’s important to modify workouts if you are feeling pain. If it is a pain that you notice more than 2 days or 2 workouts in a row, it is time to reach out for assistance.
Strengthening and therapeutic exercises should increase if you have pain. I’ll always encourage my clients to keep running if it is safe (and most of the time it is!), but modifying pace, distance or incorporate walking is key to staying healthy.
And if you’re unsure whether your pain is serious, reach out—I help runners navigate injuries and training adjustments so they can stay on track with their goals.
Have questions about a pain you’re experiencing? Reply to me to ask your questions!