Whilst medical cancer therapies are increasing in their utility and efficacy, the physiological effects of intensive combined treatment regimes on patients' reserves are becoming a greater concern. It is now routine practice to combine medical and surgical therapeutic options in the form of neoadjuvant chemoradiotherapy for conditions such as colorectal cancer. Since the 1990s we have been aware of the inverse relationship between cardiorespiratory fitness as measured by CPET and post-operative morbidity. This raises legitimate concerns over whether improvements in resection margins may come at the expense of increased surgical morbidity and mortality. Mr Malcolm West, an NIHR clinical academic fellow at the unit of cancer services in Southampton, talks to us about his ground breaking work in the field of prehabilitation medicine; the concept of improving a patient's cardiorespiratory fitness pre-operatively after a deliberate and in this case, measured toxic insult. Not only does his group's structured exercise program have a statistically and clinically significant effect on functional reserve, but this impressive pilot study hints at an unexpected and potentially yet more remarkable story.