Reducing the risk of Bone Stress Injuries in runners

Written by Mitch Kennedy - Accredited Exercise Physiologist

Bone stress injuries (BSIs) are common among endurance runners and can often occur in the lead up to a running event, which can cause a significant pain and disrupt training, depending on the severity of bone stress.

When we run, we apply load that produces stress and strain within bone tissue which produces microdamage to the bone. This is a completely normal and necessary part of our physiology as it initiates a bone remodeling response, where bone cells remove damaged tissue, and are replaced with new, undamaged tissue.

Distance runners have some of the highest rates of BSIs. This is because after a short period of running, the bone cells responsible for bone remodeling start to become bored with the monotonous, repetitive load, and (according to animal studies) become “deaf” to the signal for the bone remodeling response. The good news is that bone cells start to pay attention to the mechanical stress again after a four-to-eight-hour rest period, which is an important consideration if you are training for a running event.

There are ways to encourage strong bone tissue and promote longevity in running. Here are some tips to minimise your risk of BSI:

1. Appropriate fuelling: Eating enough calories is extremely important in supporting good bone health.  An energy deficit, where calorie intake is insufficient to meet the demands of training and daily activities, can lead to a condition called Relative Energy Deficiency in Sport (RED-S). This condition can negatively impact bone health by decreasing bone density and increasing the risk of BSIs. To learn more about RED-S, check out our blog here.

2. Periods off from running: If you participate in distance running year-round, aim to give your skeletal system structured breaks from running. This might be at least 1 day off every week, and 1 week off every 12 weeks. Periods where the bone tissue is not exposed to the mechanical stress of running will give your skeletal system a reset. You can use these periods to supplement cross-training as a way of maintaining fitness.

3. Shorter, more frequent bouts of running: If we know that a four-to-eight hour rest period is enough time for bone cells to resensitise, then consider frequent, shorter bouts of running, as opposed to longer periods of time on feet.

4. Avoid “spikes” in training volume: Since there can be delays of 3-4 weeks between a training error, and the presentation of a BSI, it is important that any increases in workload are closely monitored, particularly in the lead up to events where mileage can be relatively higher compared to general phases of training.

5. Progress duration before intensity: BSI risk increases when you run faster due to exponential increases in load magnitude. If you decide to add more intensity to your weekly running schedule, be sure it's accompanied with a reduction in your overall training volume.

6. Targeted strength and plyometric work: Plyometrics and specific strength work can be a great way of stimulating bone in different ways, through different tissues, and in different planes of motion. Introducing 1-2 exposures a week of fast, high-magnitude, multidirectional exercises can help support bone health for runners.

In summary, a runner’s risk of BSI relates to the complex interaction between changes in workload and a multitude of other factors such as biomechanics, footwear, psychology, physiology, musculoskeletal qualities, energy availability, and sleep. By implementing some of the strategies above, you can significantly reduce your risk of BSI and enjoy all the benefits that running has to offer.

If you are interested in some advice on how to integrate strength and plyometric work into your running training to support your bone health, don’t hesitate to reach out to the Eureka Health team. In particular we have Mitch, Holly, Grace, James and Chris all with excellent knowledge in this field. Book here to make an appointment.

References:

Warden SJ, Edwards WB, Willy RW. Preventing Bone Stress Injuries in Runners with Optimal Workload. Curr Osteoporos Rep. 2021 Jun;19(3):298-307. doi: 10.1007/s11914-021-00666-y. Epub 2021 Feb 26. PMID: 33635519; PMCID: PMC8316280.