As the group tackle the final fitness challenge, Michael explores stress, exercise and inner motivation. He also reveals how far they've come in 21 days - with some astonishing results
The group come together for a rooftop high-intensity training session. They also go cold-water swimming. And a self-confessed 'junk food vegan' makes some changes.
Michael runs tests on the five volunteers to assess their health, and examines what they eat. And then they begin a new training plan.
Five volunteers put their lives in Michael Mosley's hands. Can food, fitness and lifestyle changes really transform their health and well-being in just three weeks?