Kai Holden

Discover why VO2 max is the strongest predictor of all-cause mortality. Learn how to test, interpret, and improve your cardiovascular fitness.

Learn why low-intensity Zone 2 training may be the most effective cardio for longevity. Understand the science and how to find your optimal heart rate.

Combat age-related muscle loss with evidence-based strength training. Learn the exercises and protocols that protect muscle and bone density.