Aerobic respiration began hundreds of millions of years earlier than previously thought, study suggests

Oxygen is a vital and constant presence on Earth today. But that hasn't always been the case. It wasn't until around 2.3 ...

82-year-old ultramarathoner has the fitness level of a 20-year-old — what sets him apart

Most people slow down after retirement. Juan López García hit the gas. The car mechanic from Toledo, Spain, didn’t lace up ...