Running on a Treadmill and Knee Health
Running on a treadmill is not inherently bad for your knees and may actually be beneficial for many individuals, especially when compared to running on harder surfaces.
Benefits of Treadmill Running for Knee Health
Treadmill running offers several advantages for knee health:
Reduced impact forces: Treadmills provide a more compliant (softer) surface compared to concrete or asphalt, resulting in reduced peak tibial acceleration 1. This can be particularly beneficial for individuals recovering from injuries.
Controlled environment: Treadmills offer a consistent, predictable surface without the variability of outdoor terrain, allowing for better control of exercise parameters.
Lower tibial strain: Studies have shown that running on a treadmill results in lower tibial in vivo strains and strain rates compared to running overground 1.
Evidence Supporting Treadmill Running
Recent research provides encouraging evidence regarding running and knee health:
A 2023 systematic review found that running is not associated with worsening patient-reported outcomes or radiological signs of knee osteoarthritis in the short term and may even be protective against generalized knee pain 2.
Another study from the Osteoarthritis Initiative found no increased risk of symptomatic knee osteoarthritis among self-selected runners compared to non-runners 3.
For those with existing knee osteoarthritis, a 2018 study showed that self-selected running was associated with improved knee pain and did not worsen structural progression of osteoarthritis 4.
Considerations for Different Populations
For Healthy Individuals:
- Low-impact aerobic fitness exercises like treadmill running are strongly recommended by the American College of Rheumatology 1.
- The American Academy of Orthopaedic Surgeons recommends participation in low-impact aerobic fitness exercises such as walking or cycling 1.
For Individuals with Knee Osteoarthritis:
- The American College of Rheumatology and American Academy of Orthopaedic Surgeons recommend low-impact activities including walking, cycling, and swimming 5.
- Treadmill exercise with body weight support may allow for recommended training intensities to be achieved in elderly people with osteoarthritis, though it may not necessarily provide pain relief 6.
Biomechanical Factors to Consider
The relationship between surface hardness and injury risk is complex:
- Surface compliance (softness) explains less than 10% of tibial acceleration variance 1.
- Knee joint angle and muscle pre-activation have greater effects on the severity of tibial acceleration than the running surface itself 1.
- Runners often compensate for different running surfaces by altering leg stiffness depending on surface compliance 1.
Practical Recommendations for Treadmill Running
Proper footwear: Wear appropriate running shoes with adequate cushioning and support.
Gradual progression: Increase running duration and intensity gradually, following the "10% rule" (increasing weekly distance by no more than 10%) 1.
Incorporate strength training: Focus on quadriceps strengthening, which is strongly recommended for knee health 1, 5.
Maintain healthy weight: For those who are overweight (BMI >25), weight loss of at least 5% of body weight is recommended to reduce knee stress 1, 5.
Listen to your body: If knee pain develops during or after running, consider reducing intensity or taking a break until symptoms resolve.
Potential Pitfalls to Avoid
Overtraining: Excessive running volume without adequate recovery can increase injury risk.
Ignoring pain: Continuing to run through persistent knee pain may lead to more serious injuries.
Neglecting strength training: Failing to incorporate muscle strengthening, especially of the quadriceps, can leave knees more vulnerable to injury.
Improper form: Poor running mechanics can increase stress on the knees.
Running on a treadmill appears to be a safe and potentially beneficial activity for knee health when performed appropriately, with evidence suggesting it may even have protective effects against knee pain and osteoarthritis progression.