What would 10 lengths of a swimmin pool do for fitness?

I completed 10 lengths of a swimming pool in approx. 15 mins. I then went to the saunw for 10 mins and the steam room for 5. After I did two more lengths. What would this do for my fitness? Im 15 and a girl. Very sporty except im lacking fitness atm as I have not done much fitness trainin while preparing for exams.What would 10 lengths of a swimmin pool do for fitness?congraduations. keep up the good work and stay fit.