loose and baggy clothes can get in the way while working out and also trying to do push ups in a loose shirt means everyone can look up and down your shirt while it’s hanging loose and in the way. a tight shirt secures everything and keeps from being exposed. same with loose pants. a medium compression feels a lot more supportive and doesn’t get in the way while biking running etc. but definitely the tighter tops are a must for securing breasts and not creating exposure. it may seem like the right clothes are to show off body but it’s often more like the opposite- a way to hold everything in place so you have plenty of movement flexibility (tried wear loose pants to a yoga and aerobics workout once and it was awful) and security. as a bonus it helps people with vein and lymph issues to have some compression.