Regular and progressive running (such as running 10 km), even after age 40, does not disrupt hormones or damage joints; on the contrary, it strengthens the body (bones, tendons) and improves overall health.

noli's read

The creator is quite right to reassure their community: the idea that running 10 km 'burns out' hormones has no scientific basis for recreational runners. On the contrary, a large-scale meta-analysis published in the *Journal of Orthopaedic & Sports Physical Therapy* (Alentorn-Geli et al., 2017) demonstrates that recreational runners have a much lower rate of knee osteoarthritis than sedentary individuals (3.5% versus 10.2%). Hormonally, moderate running optimizes insulin sensitivity and stress management, with hormonal disturbances appearing only during cases of extreme overtraining syndrome or severe energy deficiency. Furthermore, observational studies published in *Osteoporosis International* confirm that the repeated and progressive impacts of running stimulate bone density and strengthen tendons, even with age. The concept of progressive mechanical stress mentioned by the creator is therefore perfectly consistent with the biological principles of the body's adaptation.

the sources

No named source held this one up — that absence is part of the verdict.