In this blog post we will take a closer look at what a stress fracture is, why it occurs in runners, and how the right training volume can help prevent it.
What is a stress fracture?
A stress fracture/fatigue fracture is an injury that occurs because of overload and repetitive stress on bone tissue. This injury is usually the result of increased training volume or intensity without sufficient rest and recovery time. Stress fractures are common among runners, especially those training for longer distances or marathons. In runners, the tibia (the thickest bone of the lower leg) is one of the bones most exposed to stress reactions, and it can occur at different places in the bone. Injuries at the top of the bone (the tibial plateau) and the lower part of the bone near the ankle are rare. Injuries to the middle and back part of the tibia are the most frequent. This is due to the combined stress affecting this area, both from bending forces and the contact force against the ground.
Why do stress fractures occur in runners?
Fatigue fractures are often caused by repetitive loading of the bones, especially when they do not get enough time to recover. Runners who increase their training volume too quickly, without gradual adaptation, are particularly prone to this injury. In addition, factors such as poor running technique, wrong footwear, undernutrition and underlying bone injuries can also increase the risk of stress fracture.
How can the right training volume prevent stress fractures?
The right training volume is crucial for preventing stress fractures. Here are some important tips for avoiding this injury:
1. Gradual increase in training volume: Avoid increasing your training volume too quickly. Increase distance and intensity gradually over time, so that the bone tissue can adapt to the increased load.
2. Variety: Build variety into your training by including different types of running, such as interval training, hill running and long runs. This will reduce the repetitive load on the bones and thus the risk of stress fracture.
3. Strength training: Add strength training to your training routine. Strong muscles around the bones help offload the bones and reduce the risk of injury.
4. Nutrition: Bone tissue that is exposed to high load needs energy. Low energy availability over time can lead to a reduction in bone mineral density or osteopenia. In addition, calcium and vitamin D are important factors for strengthening bone.
5. Proper footwear and running technique: Use footwear that suits your running style and make sure it is in good condition. It is also important to work on proper running technique to minimise the load on your bones. Shortening your stride length can reduce the stress on the tibia by 10%. There is also a greater chance of getting a stress fracture in the tibia when running uphill compared with running on flat ground or downhill. This is because the bending forces from muscle pull are substantially greater than the contact force against the ground. Hard uphill running therefore puts more stress on the tibia than running downhill or on flat ground.
6. Listen to your body: Pay attention to your body’s signals. If you experience pain or discomfort while running, you should take it as a sign that you need rest or that something is not as it should be. Do not ignore these signals, as it can lead to serious injuries such as a stress fracture.
Summary
A stress fracture/fatigue fracture is an injury that can occur as a result of overload and repetitive stress on bone tissue. Runners are particularly prone to this injury because of increased training volume and a lack of sufficient rest. By implementing the right amount of training, you can significantly reduce the risk of stress fracture. Listen to your body, increase your training volume gradually and include strength training to keep your bones strong and free from injury. Our practitioners have good expertise to help you with this. Get in touch if you need help.
References
- Edwards, W. B., Taylor, D., Rudolphi, T. J., Gillette, J. C. & Derrick, T. R. Effects of running speed on a probabilistic stress fracture model. Clinical biomechanics 25, 372-377, doi:10.1016/j.clinbiomech.2010.01.001 (2010).
- Rice, H. et al. Estimating Tibial Stress throughout the Duration of a Treadmill Run. Medicine and science in sports and exercise 51, 2257-2264, doi:10.1249/MSS.0000000000002039 (2019).
- Matijevich, E. S., Branscombe, L. M., Scott, L. R. & Zelik, K. E. Ground reaction force metrics are not strongly correlated with tibial bone load when running across speeds and slopes: Implications for science, sport and wearable tech. PloS one 14, e0210000, doi:10.1371/journal.pone.0210000 (2019).
- Giffin, K. L., Knight, K. B., Bass, M. A. & Valliant, M. W. Predisposing Risk Factors and Stress Fractures in Division I Cross Country Runners. Journal of strength and conditioning research / National Strength & Conditioning Association, doi:10.1519/jsc.0000000000002408 (2017).