Add Yahoo as a preferred source to see more of our stories on Google. Luis Alvarez/Getty Images Have you ever worked out and watched your muscles grow before your very eyes? You probably have, and ...
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Your body has a 'second heart', and it's crucial you keep it pumping
Veins and arteries in the leg. (szjphoto/Moment/Getty Images) Every step, ankle flex, or rise onto your toes activates a remarkable pump below your knees. Your calf muscles squeeze the veins in your ...
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