Rihana Bokhari, B.S.

You have probably heard before that exercise is good for you. You know that doctors recommend people in disease states exercise, for instance in diabetes and heart disease. But did you know that exercise can do far more than help you look good and feel great? Exercise may be able to protect you if you are exposed to radiation. Radiation is well known to have negative effects on the body and lead to illness and loss of life. In this study we seek to understand how exercise, an intervention with few negative side effects, can help to battle the effects of low amounts of radiation that astronauts and radiotherapy patients get exposed to. You might say, why don’t they just wear lead vests to protect themselves? The answer is that radiation is not always delivered in the same way. Future astronauts flying to mars will be exposed to very low amounts of extremely high energy radiation. This radiation is not found on earth and cannot be shielded by conventional methods. Radiotherapy patients encounter effects of radiation within the body after only the tumor site is exposed and small amounts of secondary radiation from the machine that provides treatment. These two kinds of unavoidable radiation are not immediately life threatening but can severely increase the risk of cancer later in life or the reoccurrence of cancer following treatment. The study that we are currently conducting is able to simulate this very low amount of radiation over an extended period of time as is seen in these two human examples. The study employs a custom designed radiation field that will deliver a constant low amount of radiation to the subject animals over 4 weeks. Exercise can be a simple prevention against the previously mentioned damage that leads to increased cancer risk. When radiation interacts with cells in the body it creates reactive oxygen species (ROS), molecules that can cause oxidative stress which is toxic to the body and can damage important structures within the cell. During exercise, small amounts of ROS activate antioxidant defenses to protect against this oxidative stress. Astronauts and radiotherapy patients may benefit from exercise because it will increase antioxidant defenses and reduce the harmful oxidative stress of radiation exposure. Exercise additionally also protects against bone, muscle and heart damage caused by spaceflight and disease. Studying changes in tissues collected on this project is one way that the protective effects of exercise will be measured. Radiation and exercise have never been studied at the same time, however, as a part of a current laboratory project we have set up a continuous low dose radiation field. Animals will exercise during their 4 week exposure period to help increase natural antioxidant defenses and protect against radiation exposure.