Exactly how little can you do and still get fit? A new study suggests 1.7 might be the magic number.

Middle-aged men and women at risk for heart disease who walk at a moderate pace for just 1.7 miles a day improve several important measures of their aerobic fitness.

More Is More
Ok, we admit it. The data show that jogging at full speed for nearly 3 miles a day reaps the greatest cardiovascular benefits. But if jogging shorts and running shoes aren't your style -- or you're just feeling kinda tired today -- at least get yourself out there for 1.7 miles. It's still enough to keep you on the road to better fitness. (Need more motivation? Find a fitness buddy you can report to daily on our message boards.)

More Ways to Do Less
Going slower doesn’t always mean that you'll lose the fitness race. Here are some other ways to keep yourself in the game when you feel like throwing in the towel:

• Slow it down. You don't have to keep up with that marathon runner. Here's why going slower may actually be better for burning calories.
• Take a breather. Right in the middle of your workout. Here's how it helps you burn more fat and calories.
• Break it up. Can't pull together 30 minutes of exercise? Grab 10 minutes in the morning, 10 minutes at lunch, and 10 minutes after dinner. Done. Here's more on the 10-minute plan.

Did You Know?
A supershort workout may have advantages, too. As long as you pick up the pace. Here's how to do it.