Flu kills tens of thousands in the U.S. each year, but the numbers vary widely by season, strain, and who gets sick. Here's what the data actually shows.
Adding a weighted vest to your walks burns more calories, strengthens bones, and challenges your heart — but there are a few things to know before you start.
Whole blood donors can give up to 6 times a year, but iron levels often determine your real limit. Here's what affects how often you can safely donate.