The Runner’s Guide to Bone Stress Injuries and Safe Return to Performance
Bone stress injuries are one of the most common overuse injuries in distance runners. In some running populations they account for around one in five injuries each year.They are frustrating, often slow to heal, and can carry a real risk of long term problems if they are ignored.
From a physiotherapy point of view, bone stress injuries are also an opportunity. They flag that something in the runner's load, recovery, bone health or biomechanics is out of balance. Get that right and you can often return stronger than before.
This article breaks down what bone stress injuries are, why they happen, how they are managed, and what athletes and coaches can do to prevent them.
What is a bone stress injury?
Bone is a living tissue. It is constantly breaking down and rebuilding in response to load. When the load is appropriate, the bone adapts and becomes stronger. When the load is too high, or recovery and bone health are not adequate, tiny cracks develop faster than the bone can repair them.
This spectrum is called a bone stress injury (often shortened to BSI):
Early bone stress
Bone is irritated and inflamed. There may be bone oedema visible on MRI, but there is no obvious fracture line.Stress fracture
The bone has developed a small crack. This is still usually due to repetitive submaximal loading, not a single big trauma.
Common sites in runners include:
Tibia (shin)
Metatarsals (forefoot)
Fibula
Navicular and other midfoot bones
Femoral neck and pelvis in higher risk cases
Clinicians often classify sites into low risk (healing tends to be straightforward) and high risk (greater chance of non union or complications, for example the navicular or femoral neck). High risk sites usually require more aggressive load restriction and closer medical supervision.
Why runners are so prone to bone stress
Running is a repetitive, impact based sport. Each stride can load the lower limb with forces around two to three times body weight. When that is repeated thousands of times per session, the total load adds up quickly.
Epidemiological studies consistently show high rates of bone stress injury in runners and in other high impact sports such as track and field, basketball, gymnastics and military recruits.
For runners, risk tends to climb when:
Training volume or intensity increases rapidly
Speed sessions, hills or plyometrics are added without an adequate base
Life stress, sleep, nutrition or menstrual health are not supporting recovery
There is a history of previous bone stress injury
A multifactorial problem, not just “too much running”
The latest international consensus on bone stress injuries in athletes is clear. These injuries are multifactorial, with mechanical loading, bone biology and overall athlete health all interacting.PubMed+1
We can group the key risk factors into two broad categories:
Internal (athlete related) factors
Low energy availability and RED-S
If athletes are consistently burning more energy than they are taking in, the body reduces investment in non essential systems. Bone formation drops, hormones are disrupted and the risk of bone stress injury rises sharply. This is captured in the concept of Relative Energy Deficiency in Sport, which is strongly linked with bone stress injuries.Low bone mineral density or previous BSI
A history of stress fracture or low bone density is one of the strongest predictors of future bone stress injury.Menstrual disturbances and hormonal factors
In women, delayed menarche, irregular periods or amenorrhoea are red flags that bone may not be receiving adequate hormonal support. In men, low testosterone or other endocrine issues can play a similar role.Biomechanics and anatomy
Factors such as very narrow tibiae, leg length differences, high arches, excessive pronation or supination, or hip weakness can influence how load is distributed through bone. These do not guarantee injury, but they change the load puzzle.Training history
Runners with backgrounds in aesthetic sports such as ballet or gymnastics seem to have higher risk, possibly due to historical low energy availability and high impact training from a young age.PMC
External (training and environment) factors
Rapid spikes in training volume, frequency or intensity
Sudden introduction of hill running, speed work or plyometrics
Hard or cambered surfaces, especially when combined with fatigue
Footwear changes, particularly switching to a more minimalist or “super shoe” model without a transition
Competition schedules that do not allow time for recovery or progressive loading
For physiotherapists, athletes and coaches, the key message is that bone stress injuries rarely have a single cause. They arise when several risk factors pile up around a bone that is being loaded at, or beyond, its current capacity.
Recognising early warning signs
Catching bone stress injuries early can significantly shorten recovery. Some typical features runners report are:
Localised, deep bone pain that worsens with impact loading
Pain that starts only at higher volumes or speeds, then appears earlier and earlier in the run
Pain that lingers after sessions, or appears with simple walking if more advanced
Local tenderness to touch over a small area of bone
Sometimes, mild swelling
Shin pain can be confusing, as medial tibial stress syndrome (traditional “shin splints”) and tibial bone stress injury sit on the same continuum. If pain is not settling with sensible load adjustment, or if it is very focal on the bone, it is safer to assume bone stress until proven otherwise.
Red flags that warrant prompt medical review and imaging include:
Sudden sharp pain with an audible “crack”
Night pain that is unrelated to activity
Pain in high risk areas such as the hip or groin
History of significant menstrual disturbance, eating disorder or known low bone density
How a physiotherapist assesses a suspected bone stress injury
A thorough physiotherapy assessment will usually include:
Detailed history
Training loads over the last three to six months
Recent changes in volume, intensity, surface or footwear
Menstrual history and energy availability questions
Previous injuries, especially previous bone stress injuries
Nutrition patterns and any history of RED-S or eating concerns
Physical examination
Local palpation for focal bone tenderness
Functional tests such as single leg hop or step downs, if appropriate
Assessment of strength, flexibility and running mechanics
Imaging
Plain X rays can be normal in early stages
MRI is the gold standard, as it can detect early bone oedema and grade severity on a spectrum, which helps guide prognosis and return to run timelines.
Based on the latest consensus, classification systems now look at both the site of injury and the severity on imaging to determine risk and guide management.
Management: unloading to reload
The core principle of bone stress injury rehabilitation is simple:
Reduce bone load enough to allow healing, then gradually reload in a structured way.
The specifics depend on the site and severity of the injury, but physiotherapy management typically involves:
1. Relative rest and load management
High risk injuries or advanced stress fractures often need a period of non weight bearing or protected weight bearing in a boot under specialist supervision.
Lower risk injuries may only require removing impact loading and painful activities, while maintaining pain free cross training (for example bike, deep water running or swimming).
A physio can help create a clear plan that balances protection of the bone with maintenance of fitness.
2. Addressing energy availability and bone health
If there is any concern about low energy availability, RED-S or poor bone health, this must be addressed early. That may include:
Referral to a sports physician, dietitian or psychologist
Ensuring adequate total energy intake
Prioritising protein, calcium and vitamin D
Screening for other medical contributors to low bone density
Ignoring this side of the puzzle raises the risk of recurrent or multiple bone stress injuries.
3. Strength and conditioning
Even when running is off the table, most runners can continue meaningful strength work. A physio guided program will often:
Maintain or improve hip and calf strength
Target any side to side asymmetries
Introduce progressive, bone loading exercises in a controlled way, for example squats, deadlifts and step ups in later stages
Well designed strength work not only supports bone, it also improves tendon and muscle capacity, which can offload bone during impact.
4. Running mechanics and footwear
Where relevant, the rehab process may include:
Gait retraining, such as cadence changes or step width adjustments
Gradual transition to any new footwear type
Education about surface choices during the return to run phase
This is not about forcing everyone into one “perfect” technique. It is about identifying patterns that overload the injured region and making practical changes.
5. Staged return to running
Once walking is pain free and the runner tolerates hopping or low level plyometrics without symptoms, a graded return to run program can begin. A physio might structure this as:
Walk run intervals on alternate days
Gradual increases in total running minutes
Monitoring of pain during the run and for 24 hours afterwards
Simple tracking of weekly load, using distance or time plus a session RPE score to generate training load numbers
The key is that pain stays low and does not worsen across the week, and that overall training load increases are modest, often in the range of 5 to 10 percent per week during early return.
High risk injuries, such as femoral neck or navicular stress fractures, will also be guided by medical and imaging review timelines.
Prevention: building a bone friendly running program
For athletes and coaches, prevention strategies sit across several domains.
Training structure
Avoid large, sudden spikes in weekly volume or intensity.
Build in at least one lighter week every three to four weeks, where overall load is reduced.
Introduce hills, speed work and plyometrics gradually on top of a solid aerobic base.
Be cautious when stacking high impact sessions close together, for example long run, track session and plyometrics in the same 48 to 72 hour window.
Monitoring load and wellness
Simple tools such as:
Training logs that record distance or time plus session RPE
Brief wellness check ins that note fatigue, soreness, sleep quality and mood
can help identify accumulating stress before injury appears.
Supporting bone health
Promote adequate energy intake relative to training, especially in growing athletes and those in high volume programs.
Encourage athletes to speak up about menstrual changes or fatigue rather than normalising them as “part of training”.
Include year round strength training rather than only in the off season.
Technique and footwear
Periodically review running mechanics, especially when athletes are increasing volume or changing events.
When changing footwear, transition gradually rather than switching overnight.
Key takeaways for athletes
Bone stress injuries are common in runners, but they are not random bad luck.
Persistent, focal bone pain with running is a reason to see a physiotherapist or sports doctor early.
Successful rehab is not just about rest. It is about solving the load and bone health puzzle, then building back capacity step by step.
With a structured plan and the right support, most runners can return to, and often exceed, their previous level.
Key takeaways for coaches
Watch for athletes who increase training quickly, change events or surfaces, or who show signs of low energy availability and fatigue.
Make it normal for athletes to communicate about niggles, menstrual health and tiredness.
Work closely with physiotherapists and sports physicians when a bone stress injury is suspected, so that training can be adjusted rather than stopped altogether.
Invest in strength training and sensible periodisation. These are among your best tools for protecting your squad's bones.
At SurfEdge Sports Physiotherapy we work closely with runners at every level, from recreational athletes to high performance competitors, to identify bone stress risk early and guide a structured return to running when injuries occur. If you are dealing with persistent bone pain or want help designing a safer and more effective training plan, get in touch and our team can support you through assessment, management and performance programming.