Squats. "Knee joints deteriorate naturally with age. When you're in your 40s, it's best to avoid exercises that can damage any joints, and squats require a lot of strength in your knees," says Velikova.

What exercises not to do after 40?

Here is a look at seven exercises people over 40 should avoid.

Can you reshape your body after 40?

It's never too late to get in shape and reap the health benefits of physical fitness. So says a new study published in the journal JAMA Network Open.