This programme looks at the problems of investigating the continually changing process of exercise and fitness training by looking at the work of Malcolm Emery and his team at Borrough road. We will see one technique called the Bruce Protocol which involves a volunteer exercising on a special bicycle with progressively increased resistance applied until exhaustion. Heart rate, breathing rate, cardiac output, tidal volume, blood gas content, pH, and lactate levels are all measured. Exhaustion occurs at different times and for different reasons depending on 'fitness'. Normal subjects are usually restricted by their muscles, an endurance athlete will be limited by cardiac output and will continue for much longer, whilst an asthmatic will be limited by the lungs. As part of the application of this work Malcolm's group are helping Eric Shaw to regain his fitness after a series of heart attacks and recent open heart surgery. eric, a fanatical golfer, is making remarkable progress demonstrating the importance of both understanding and undertaking physical exercise and training.