This is a common question asked in interviews. The interviewer wants to learn more about you as a person, what hobbies you are interested in, and that you prioritize time for yourself away from your studies. Medical school and your future career as a physician will be challenging and demanding of your time. It is important to spend time doing things you enjoy to alleviate stress and prevent burnout, such as exercising, meditating, reading books for pleasure, spending time with friends and family, playing music, or being creative.
This is also an excellent time for the interviewer to discuss the student support offered at Indiana University School of Medicine, in case you weren't aware. IU has many campuswide resources, including a Student Recreational Sports Center (SRSC) where you can "sweat out your stress with fitness classes, 400 pieces of cardio/weight-training equipment, and intramurals," libraries, and student organizations where you can make new friends. Let the interviewer know what you enjoy doing in your free time and how you are excited to utilize the resources offered at IU.