In the movie "Pitch Perfect," the captain of the a capella group the Barden Bellas decides they all need to get in shape, so she has them run around the gym.

She comes over to one of the Bellas, Amy, to ask why she's lying on her side. "I'm doing horizontal running," Amy responds, lazily cycling her legs in the air.

If you're a horizontal runner like Amy, it's time to get vertical and start walking, cycling and, yes, doing more effective horizontal exercise, like swimming.

Why? It can boost your chances of a sharper mind as you age.

Scientists used to think people lost cognitive ability because their brain's nerve cells died off with age, but it turns out that's not the case.

Researchers looked at the brains of 28 people ranging from 14 to 79 and found that older folks made as many new neurons in the brain regions associated with memory as younger people, but had less oxygen-delivering blood flow to these areas.

The researchers suggest lack of oxygen could cause age-associated cognition problems.

How do you increase blood flow to your brain? Stand on your head?Not if you have joint, spine or cardio problems.

Instead, aim for 10,000 steps daily or the equivalent, and get at least 150 minutes of added aerobic exercise weekly.

Also try yogic deep breathing: Expand your lungs outward as you inhale for the count of four and exhale slowly from the bottom of your lungs first (your belly will sink in) for a count of eight.