Prof Thomas talks to ecancertv at NCRI 2015 about how physical activity can benefit a cancer patient's health and wellbeing.
Three to four hours of exercise a week is enough, he says, to make a significant difference to individuals and health systems.
He explains how a lot of people think they shouldn't exercise because it will increase the problems associated with their cancer, such as joint pain or fatigue. Actually, he says, exercise can relieve these symptoms. This is a point that needs more emphasis and understanding from healthcare professionals and patients.
Prof Thomas is also a visiting professor of Applied Biology and Exercise Science at the Coventry University.