Can exercise make you think better? In some cases, yes. Here's what works best.

Aerobic Training

Don't cut that PE class! In 2006, Arthur Kramer of the University of Illinois used MRIs to prove that aerobic exercise builds gray and white matter in the brains of older adults. Later studies found that more aerobically fit grade-schoolers also perform better on cognitive tests.

__Impact on intelligence: __ Strong

__Lifting Weights __

When weight lifters talk about getting huge, they aren't referring to their hippocampus. Researchers have found only the most tenuous link between heavy resistance training and improved cognitive function. Got that, meathead?

__Impact on intelligence: __Negligible

Yoga

When facing a stressful situation or even a scary email, people often hold their breath. Yoga can break that habit. Under pressure, "most people breathe incorrectly," says Frank Lawlis, a fellow of the American Psychological Association and author of The IQ Answer. The result: more stress and less oxygen to your brain. "So the first thing that goes is your memory."

Impact on intelligence: Possibly strong

Studying on the StairMaster

A spinning class may rev up your mental muscle, but that doesn't mean you should study while huffing and puffing on the StairMaster. Research shows you'll just confuse yourself. "It's like doing something while you're driving," says Charles Hillman, a kinesiology professor at the University of Illinois. In other words, you won't do either task well.

Impact on intelligence: Negligible

Illustration: Christoph NiemannRelated Get Smarter: 12 Hacks That Will Amp Up Your Brainpower 1: Distract Yourself 2: Caffeinate With Care 3: Choose Impressive Information 4: Think Positive 5: Do the Right Drugs 6: Juice Your IQ Score 7: Know Your Brain 8: Don't Panic 9: Embrace Chaos 10: Get Visual 11: Exercise Wisely 12: Slow Down Plus: 6 Intelligence Myths Exposed