Stress fractures are quite common in sport; they’re estimated to make up around 15 per cent of running injuries. They might just look like tiny cracks in a bone but can take you out of running for months at a time so aren’t minor at all. It isn’t always easy to know whether the pain you have is just a niggle and you can keep running or whether it could be a stress fracture. Let’s explore what causes them, how you might know if you’ve got one and when to see a doctor.
What actually is a stress fracture?
Bones love a bit of stress, in fact, it’s when you stress them that they strengthen. Whether it’s impact with the ground as you run or your tendon tugging on the muscle as you lift a weight, that stress is what stimulates bone growth. Astronauts in space quickly lose bone mass as they float around gravity free. As usual, too much of a good thing can be bad and if there’s too much stress then cracks can form and a stress fracture is the result. Most stress fractures are in the lower leg, the shins and feet are the most common location for runners with stress fractures but you’ll hear of them in the upper leg (femur) and pelvis too. Shin splints and stress fractures are often confused but they are not the same thing. Read my blog on shin splints for more information.
Why have I got a stress fracture?
If the balance between the stress put on a bone and its ability to recover, repair and strengthen itself is wrong then the bone can be damaged.
Causes of stress fractures in runners:
- Running too far
- Running too frequently
- Increasing running miles too quickly
- Inadequate rest
- Poor nutrition – the body doesn’t have the building blocks or energy it needs to make bone
- Injuries and poor biomechanics which result in unusual stress on bones
- Low bone density – osteopenia or osteoporosis. Bones are already weakened and fracture more easily. This is more common in postmenopausal women
- Fatigued or weak muscles which are unable to help absorb impact which results in extra stress on the bone.
- It’s not clear whether certain running styles such as heel-striking or forefoot running put you at an increased risk of stress fracture. Similarly, it’s not clear whether cushioned shoes reduce your risk.
It’s not clear whether certain running styles such as heel-striking or forefoot running put you at an increased risk of stress fracture. Similarly, it’s not clear whether cushioned shoes reduce your risk.
Warning signs that you may have a stress fracture
How do you tell the niggle from the fracture? How do you decide whether it’s OK to keep running? Here are six warning signs that might indicate you have a stress fracture in which case you should get a medical opinion:
- Pain comes on suddenly. You can pinpoint the day the pain started, this is unlike lots of other musculoskeletal injuries which worsen more slowly.
- It hurts more when you run. Stress fracture pain isn’t going to ease up by warming up and running a few miles, it gets worse with activity.
- Pain on resting. This is an important one, especially if you have pain at night.
- Point tenderness. Rather than a vague area of pain you can put your finger on exactly where it hurts.
- There’s swelling. Bone injuries often cause swelling in the soft tissues around them. Remember gravity might take that tissue fluid down to your ankle or foot.
- You have a higher risk of bone fracture. If you know you have osteopenia or osteoporosis or you have had a stress fracture before then you should have a higher index of suspicion.
What should I do if I think I have a stress fracture?
First up, stop running. Don’t train on what you think might be a bony injury. Ease any pain with paracetamol and ice packs. If you’re unsure as to whether you have a soft tissue or a bony injury, a physiotherapist can be a great help.
Stress fractures don’t always show up straight away on x-rays so you might end up getting referred to a doctor for a CT or MRI scan. Some physios can organise these directly. Stress fractures usually take around eight weeks to heal and it’s really important that you follow instructions and rest properly. You can often cross-train if it doesn’t cause any pain but check with your doctor.
Your return to running should be planned, gradual and only begin once you are clear as to whether there are any underlying causes for your fracture and the causes of stress fractures in runners have been addressed.
To learn more about bone health and running, head to my book Run Well: Essential health question and answers for runners, published by Bloomsbury and available from all good booksellers.

Featured image: Vilius Kukanauskas from Pixabay