Recent studies have shown that survival after a colorectal cancer diagnosis may be affected by a person's activity level and body size. This research says that for colorectal cancer patients, the less active and more obese they are, the more likely they are to have a cancer recurrence or die from their cancer. Chemotherapy has been shown to reduce activity levels, fitness, and body size in some cancer patients. However, it is not known how chemotherapy specific for colon cancer patients affects their activity levels, fitness, and body size. The main goal of our study will be to look at how chemotherapy treatments affect the fitness, activity levels, and body size in colon cancer patients. In order to do this, we will measure these variables before chemotherapy treatments, and at 1 and 6 months following the end of treatment. Our results will show how chemotherapy affects fitness, activity levels, and body size in colon cancer patients and provide data to help in designing an exercise intervention specifically for colon cancer survivors.