This Nutrient Improved Bone & Inflammation Markers In Female Runners

Running is one of the most accessible ways to build cardiovascular fitness, clear your head, and stay strong as you age. But the repetitive impact that makes it so effective also puts stress on your bones, especially if you're logging serious miles.

A new pilot study published in Frontiers in Nutrition1 explored whether collagen peptide supplementation could support bone health in female endurance runners (and the results are promising). Here's what you need to know.

About the study

Researchers wanted to test whether daily collagen peptides could influence markers of bone turnover and inflammation in women who run at high volumes. Bone stress injuries affect a significant portion of female runners each year, particularly those training at high intensities or dealing with low energy availability. While collagen supplements have gained popularity for joint and skin health, their effects on bone remodeling in active women have been less studied.

To investigate, the team recruited 22 premenopausal, endurance-trained women who ran at least 35 miles per week. Participants were randomly assigned to take either 20 grams of collagen peptides or a placebo daily for four weeks. Before and after the intervention, researchers measured several biomarkers: P1NP (a marker of bone formation), CTX-1 (a marker of bone resorption), IL-6 (an inflammatory cytokine), and sRANKL (a protein that promotes bone breakdown).

Collagen group showed increased bone formation and lower inflammation

After four weeks, the collagen group showed a 5.1% increase in P1NP, indicating greater bone formation activity. The placebo group, by contrast, saw a slight decrease in this marker. IL-6 levels dropped significantly in the collagen group, suggesting reduced systemic inflammation. The collagen group also experienced a decrease in sRANKL, while the placebo group saw an increase (a potentially meaningful shift since sRANKL promotes the activity of cells that break down bone).

One marker, CTX-1 (which reflects bone resorption), did not change significantly in either group. This suggests that collagen's benefit in this study was primarily on the formation side of the bone remodeling equation rather than slowing breakdown.

Why these markers matter for runners

Your bones are constantly remodeling, which means old bone tissue is being broken down and new tissue is being formed. But high training loads, inadequate fueling, or low energy availability can tip the scale toward breakdown, increasing the risk of stress fractures and other bone injuries.

The fact that collagen supplementation appeared to support bone formation (P1NP) while also lowering markers associated with inflammation (IL-6) and bone breakdown signaling (sRANKL) is encouraging. For female runners who face unique risks related to hormonal fluctuations, energy availability, and training volume, these shifts could be meaningful for long-term skeletal health. Pairing collagen with inflammation-fighting foods may further support recovery.

How to incorporate collagen into a running routine

The study used 20 grams of collagen peptides per day, which is on the higher end of typical supplement doses. If you're considering adding collagen to your routine, here are a few things to keep in mind:

The takeaway

While this is a small study, collagen peptide supplementation appeared to support bone formation and reduce inflammation in female endurance runners—a promising signal for those concerned about bone health. For now, collagen remains a reasonable addition to a well-fueled running routine, but it's not a replacement for proper nutrition and recovery.