[Catherine]

Hey JGrez

I've actually taught swimming and coached a high school team for a few years. If you are a lifeguard then you must have some decent skills in he water, but it sounds like your endurance is lacking. Put some time in doing some distance swims. At least 500 m to start. Remember to breath often when doing endurance (every 2nd to every 3rd stroke = bilateral). When you start to pick up speed for sprints then you can breath fewer times because you'll only be going for a short time (hopefully less than 1:00 for 50 m!!) and your body can catch up on the O2 deficit once your done.