"Hearst Magazines and Yahoo may earn commission or revenue on some items through the links below." YOU MIGHT THINK back to your childhood gym class and remember learning the basics of physical fitness ...

Look, I used to think those “100 jumping jacks = 10 calories” calculators were gospel. Then I started paying attention to real people doing real workouts, and wow – was I wrong. Those generic formulas ...

It's called anaerobic endurance, and it's that crucial physical ability that sets apart good athletes from those who truly shine. Whether you're a weekend warrior or a seasoned fitness enthusiast, ...