Written by Tom Eather, Physiotherapist, BeFit Training Physiotherapy. Published 10 October 2025. Last reviewed 24 July 2026.
Often when we are active, it is common to get some discomfort both during and after exercise. This is totally normal and expected, meaning we shouldn’t fret about it. But how do we know if something is a niggle, or if it’s a more serious issue that we should pay attention to?
There are no absolutes, but there are some basic principles to follow that can help you identify whether your pain is resulting from a normal breakdown and repair cycle we encounter after exercise, or whether it’s an injury that may be more serious. These principles centre broadly around pain behaviour. In this instance, we’ll use running as an example.
First: When to Stop and Seek Assessment Regardless
Everything below assumes none of the following apply. If any of them do, the guidance in this article does not apply to you, and you should arrange an assessment rather than working through a self-check.
- You cannot put weight through the limb, or you heard or felt a sudden pop, tear or snap
- Pain that came on after a fall, collision or other trauma
- Pain that wakes you at night, or that is present at rest and unrelated to activity
- Numbness, pins and needles, or weakness that is getting worse
- Calf pain with swelling, warmth or redness, particularly after a long flight, surgery or period of immobility
- Fever, unexplained weight loss, or feeling generally unwell alongside the pain
- Changes to bladder or bowel control, or numbness around the groin or inner thighs
Some runners also carry a higher baseline risk of bone stress injury and should have pain assessed earlier rather than later. This includes anyone with a previous bone stress injury, low bone mineral density, irregular or absent periods, a recent sharp increase in training load, or a history of restricted eating relative to training demands.
Pain Intensity
Pain intensity can be a useful indicator of whether your issue is a niggle that can be run through, or something more serious that should make you stop running. If you’re training for a full or half marathon, your weekly kilometres can be large, and it’s expected to have some discomfort during those high volume weeks.
A traffic light system, adapted from the pain-monitoring model used in tendinopathy rehabilitation, is a helpful rule of thumb for deciding whether to continue running:
- 0-4/10 = Green zone (continue)
- 5-6/10 = Orange zone (beware, it might be worth stopping)
- 7+/10 = Red zone (stop)
An important caveat: this model was developed for people with a known, diagnosed condition who are working through a supervised rehabilitation programme. It tells you whether a given level of pain is likely to be safe to load, not whether the underlying problem is serious. Some injuries that need prompt attention, including bone stress injuries, can sit comfortably in the green zone. Use intensity alongside the other factors below rather than on its own.
Activity-Related Pain
How pain behaves in response to loading is a good indicator of whether an issue is a niggle. If your pain starts at the beginning of the run but subsides after a kilometre or two, it “warms up,” and in that instance it’s generally fine to continue running.
If your pain worsens as you’re running, that’s a sign your issue may be more serious and might require further assessment. Similarly, pain that hangs around long after your run is worth paying attention to, as ideally pain should subside if not immediately, then within an hour or so. This doesn’t include post-exercise muscle soreness, which can hang around for a couple of days afterward.
Non-Activity-Related Pain
Pain that isn’t related to activity can be a sign that your issue might be more serious. Night pain in particular is a recognised red flag for bone stress injuries in runners, and should prompt a detailed assessment to rule out anything more significant.
Pain Quality
Pain quality can also help guide how seriously to treat an issue. Dull aches are usually more consistent with a niggle, while sharp pain is often more serious.
Pain with nerve-related qualities, such as sharp, shooting or electric sensations, is generally a flag for something more significant than a niggle. Similarly, pain involving numbness, tingling, or associated weakness is an issue that warrants an assessment.
Getting an Accurate Diagnosis
As you can see, there are a variety of factors we look at when deciding whether an issue is a serious pathology or a manageable niggle. Pain intensity, behaviour and quality are all important pieces of information that help build a picture of your current issue.
This is where a thorough running assessment is paramount to arriving at an accurate diagnosis, which is why physios ask a lot of questions during your initial consultation.
You can use the information above to help make sense of your current issue, but if you want an expert assessment, diagnosis and treatment plan, our Sports Physiotherapy team is here to help.
Book an Appointment
Book an appointment at BeFit Training Physiotherapy. No referral needed.
BeFit Training Physiotherapy Edgecliff
Ground Floor, 287-289 New South Head Road, Edgecliff NSW 2027
Phone: (02) 9327 7749
BeFit Training Physiotherapy Coogee
Shop 1/2 Byron Street, Coogee NSW 2034
Phone: (02) 7205 2805
References
Silbernagel KG, Thomee R, Eriksson BI, Karlsson J. Continued Sports Activity, Using a Pain-Monitoring Model, During Rehabilitation in Patients With Achilles Tendinopathy: A Randomised Controlled Study. Am J Sports Med. 2007;35(6):897-906.
Warden SJ, Davis IS, Fredericson M. Management and Prevention of Bone Stress Injuries in Long-Distance Runners. J Orthop Sports Phys Ther. 2014;44(10):749-765.
