Your monthly period can put a crimp in some of your daily activities, but swimming and exercise shouldn't be a problem. Some women think swimming while on their period is not an option, especially if they don't wear tampons, but that isn't true. According to the Kotex website, swimming is a great exercise for a woman having her period because the water lifts the body up and takes pressure off the back, relieving cramps.
Place a reusable cotton pad in the crotch of your swimsuit. Make sure you use one that does not have wings, because those will be visible on the outside of your swimsuit. Cotton or cloth pads are reusable and will not disintegrate in water while you are swimming. According to the Lunapads website, the cloth pads can last up to five years and replaces about 120 pads or tampons in its lifespan.
Wear your swimsuit normally. Adjust the pad so it covers the entire crotch area and can't seen from the outside of your swimsuit. Check to make sure the pad is secured in your swimsuit, so it won't float out while you swim.
Swim in a pool, lake or ocean. You will be able to move freely with the pad in your swimsuit, so swim normally. According to the Children, Youth and Women's Health website, the water will wash the blood away from the vagina, and after a few minutes the amount of blood loss will be too small to notice.
Insert a tampon if you have a heavy period. Even though the water will wash away a small amount of blood, it is more sanitary to contain the blood than to let it flow out into the water. A tampon will help contain the blood, and you can use it with or without a pad.
Remove the pad and tampon when you get out of the water. The water will fill the tampon or a pad, making either unable to absorb any more blood. Put a fresh pad or tampon in before returning to the pool or beach. Repeat this step after returning to the water.