“Heart Beast” — The Discovery Files

For over 30 years, Terrie Williams has been studying exercise physiology in wild animals: African lions and wild dogs, dolphins and whales, coyotes and mountain lions, as well as a few human athletes. She has put mountain lions on treadmills and strapped heart-rate monitors onto big-wave surfers at Mavericks. These studies have given Williams, a professor of ecology and evolutionary biology at UC Santa Cruz, a unique perspective on exercise and health.