The next time you're at the beach, take a break from relaxing in the sun and get up and move around. Resist walking on the flat sand right at the water's edge and go for the dry sand. Ditch your shoes so you can really use your toes to grip the ground. Walking barefoot in the sand is not only great for the muscles in your feet and your calves, but because it's so much harder than walking on a flat surface, you'll burn more calories. If your feet get hot, you can always cool off by walking on the wet sand, which is great for exfoliating the dead skin cells from your heels.