Just be aware that swimming builds a different type of muscle than impact cardio (like running) does. In swimming you are building long smooth muscles that are good at continuous effort over a range. In running, the muscles are much bunchier and are more explosive. Obviously, HIIT type running will produce the most explosive muscle fibers (relative to swimming or long distance running).
This was readily noticable to me in my calves when switching sports from swimming to soccer as a child. That said, swimming will also provide more of an overall muscle endurance workout in addition to the cardio than running does. Swimming hard makes me tired in a way that running never can.
This was readily noticable to me in my calves when switching sports from swimming to soccer as a child. That said, swimming will also provide more of an overall muscle endurance workout in addition to the cardio than running does. Swimming hard makes me tired in a way that running never can.