A 2023 human study investigated exercise, klotho gene, and epigenetic clock relationships:

“Named after the spinner of the thread of life, klotho (KL) is involved in the aging process and may act as an anti-aging hormone in mammals. We hypothesize that circulating KL is correlated with age-associated methylation of the KL gene promoter region, and this is one reason for age-related decline in circulating KL.

202 subjects between ages 37 and 85 were included in the study. A great percentage of volunteers participated in the World Rowing Masters Regatta in Velence, Hungary. They were considered to be the trained group (TRND): n = 131; 80 males: age 59.14 ± 10.8; 51 females: age 57.24 ± 9.4. Results were compared to the sedentary group (SED): n = 71; 27 males: age 55.63 ± 13.4; 44 females: age 61.91 ± 10.5.

Circulating level of KL showed a negative correlation with chronological age in the TRND group, but not in the SED group.

Examining the relationship between circulating KL level and PhenoAge and GrimAge, KL is associated with PhenoAge acceleration in the TRND group only. It appears that higher KL can decelerate the DNA methylation-based aging process assessed by PhenoAge.

The present study revealed that circulating KL level is associated with exercise status level and general strength level, and is greatly dependent upon exercise-induced DNA methylation.”

https://www.mdpi.com/2073-4425/14/2/525 “The Circulating Level of Klotho Is Not Dependent upon Physical Fitness and Age-Associated Methylation Increases at the Promoter Region of the Klotho Gene”