Drs Chris and Xand explore the science of exercise and the dangers of inactivity.
Series 3: Exercise homepage
Drs Chris and Xand van Tulleken explore if people can change and how they do it.
Series 2: Can I Change? homepage
Chris van Tulleken is on a mission to get his twin Xand to quit ultra-processed food.
Series 1: Addicted to Food homepage