Look, I’m gonna be straight with you – those online calculators that tell you exactly how many jumping jacks you need to burn 500 calories? They’re basically making educated guesses about your body.

Jumping jacks are an efficient total-body workout that you can do almost anywhere. This exercise is part of what’s called plyometrics, or jump training. Plyometrics is a combination of aerobic ...

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 ...