CNN’s Bianna Golodryga speaks to Steven Johnson, author of “Extra Life: A Short History of Living Longer,” about some of the discoveries and innovations that have led to the average human life expectancy almost doubling over the last century.

Home Fitness Innovations: The Future of At-Home Workouts
The way we work out has changed — and it’s not just a temporary shift. Over the past few years, home fitness has transformed from