Walking is one of the best forms of cardio exercise you can perform. The reason is simple - it's low-impact, and you're more likely to stick to a walking program than any other type of exercise. A half-hour or 45-minute walk four days a week will help greatly in keeping you heart-healthy (if you think you don't have time for a full half hour, you can plug in 10 minute walking breaks here and there throughout the day - you'll be surprised at how much you can fit in!). Walking is as easy as stepping out the door - that is, unless it's raining, sleeting or you live in a scary neighborhood. But you don't have to let inclement weather or bad characters keep you from a daily walk - that's where a treadmill comes in. Not only is it handy if you can't walk out of doors, it's also a great tool if you take your walking - or running - program more seriously than most. You can pace yourself, do hill training with the use of the incline option, and try interval training. Most treadmills also come with ideal surfaces for walking and running, so they're kinder on your joints than the sidewalk. If you make use of a treadmill's many options, you'll rarely have time to get bored, but if you do, a nearby television or a CD or MP3 player containing your favorite tunes can keep your mind occupied. Nearly everyone who follows a fit lifestyle should have access to a treadmill. If you have the budget and room in your home, you might consider owning one. If the price tag of a new treadmill is too steep, look into buying one used on eBay or from an ad in the paper. If owning one isn't an option, join a gym. Keep in mind that many YMCAs also have treadmills. Add a treadmill to your fitness program and you'll never have to miss a cardio workout!