Whether you enjoy doing it or not, you know your daily workout is good for you. Good for your muscles. Good for your bones. Good for your heart. But did you know that it’s also good for your brain? Older people who exercise regularly — and face it, the habit begins when you’re much younger — have a slower rate of decline in thinking skills that naturally occurs with aging. And it makes a big difference. People who reported light to no exercise experienced a decline equal to 10 more years of aging as compared to people who reported moderate to intense exercise, according to researchers from the University of Miami in Florida and Columbia University in New York City. Translation: Spending 30 minutes speed-walking on a treadmill most days of the week will help you keep your wits about you much longer than if you are sedentary. More than anything else, it will help you delay the cognitive effects of aging.