Lost in Space: Just how much exercise do I need each week

The questions lurk in the back of many of our minds—and here are the answers, according to two experts Fortune spoke to.

• Adults ages 65 and older should add to this routine activities to improve balance, such as standing on one foot.

• Adults with chronic health conditions and disabilities should get 150 minutes a week of moderate-intensity activity, with two days a week of muscle-strengthening work.