RecruitingBehavioural interventionExercise for Gut Microbiome in Patients With Young-Onset Colorectal Cancer Undergoing Chemotherapy: The COURAGE TrialThis research study is a randomized controlled trial that will observe changes in microbiome activity, changes in chemotherapy toxicity, and any changes in treatment outcomes between two groups of participants undergoing chemotherapy with either early-stage or metastatic colorectal cancer. The names of the study groups involved in this study are: * Exercise * Waitlist Control