The issue: Many runners (particularly women) report that their fitness trackers tell them they’re exercising in a higher zone ...

Editor’s Note: Published in 1959, this article comes from Martin Gardner’s legendary Scientific American column Mathematical Games. Read more classic Mathematical Games articles in our 2024 special ...

Hallie Levine is an award-winning health and medical journalist who frequently contributes to AARP, Consumer Reports, the New York Times, and Health.com. She lives in Fairfield, CT, with her three ...

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Thomas J Catalano is a CFP and Registered ...