Truth: If you're looking to lose weight, you shouldn't assume that you can simply "work off" whatever you eat. Experts say slimming down almost always starts with significant changes to your eating habits.

"In terms of weight loss, diet plays a much bigger role than exercise," University of Texas exercise scientist Philip Stanforth tells Business Insider.

That said, being active regularly is an important part of any healthy lifestyle. And when it comes to boosting your mood, improving your memory, and protecting your brain against age-related cognitive decline, research suggests exercise may be as close to a wonder drug as we'll get.