Swimming with an injured knee

It's funny how few people realize that "swimming" as a form of exercise doesn't refer to just floating around the pool and relaxing, but it's actually doing laps. Swimming is actually MORE exhausting than running, as it's harder to breathe steadily.

For this reason, if you have an injured knee, you're advised against doing serious "swimming". It can lead to more damage, so stick with the simple options like water aerobics or swimming laps slowly.