"It was surprising when we looked at similarities between astronauts during spaceflight and cancer patients during treatment. Both have a decrease in muscle mass, and they have bone demineralization and changes in heart function," says senior author Jessica Scott, an exercise physiology researcher at the Memorial Sloan Kettering Cancer Center's Exercise Oncology Service. The similarities also extend to brain function: "Astronauts may get something called space fog, where they have trouble focusing or get a little forgetful. That's very similar to what some cancer patients experience, which is called chemo brain."
Despite similar symptoms, astronauts and cancer patients often receive very different advice on how to take care of their bodies. Astronauts are required to exercise prior to their mission while physicians monitor their cardiorespiratory fitness and other systems to develop a baseline level. The astronauts are then required to exercise during their mission utilizing special equipment made for working out in space. When they return to Earth, physicians continue to monitor the astronauts until their cardiorespiratory fitness and other systems return to their pre-mission baseline levels.
"That's completely backwards to how it is on Earth, where cancer patients may still be advised to rest in preparation for and during treatment and may have to ask permission to exercise from their physicians," says Scott.
But Scott and her team of researchers suggest that basic exercise such as walking on a treadmill could benefit cancer patients in the long term. Like astronauts preparing for spaceflight, cancer patients that are monitored using similar tests such as cardiorespiratory fitness could develop their own baseline levels prior to receiving treatment. Exercising during and after treatment could then potentially reduce the negative side effects of treatments such as heart problems.