Jogging is a very good way to stay fit. However, there are many who couldn't get into it for a number of reasons. Some have medical conditions that prevent them from jogging, while many others, this writer included, couldn't do so because of weak knees and much weaker ankles. That is why more and more people, this writer included, instead take up walking as their primary aerobic exercise.
However, from an alpha male point of view, walking seems to be for sissies. You don't see too many guys walking around Central Park, do you? But the truth is, walking provides as much benefits as jogging. In fact, any walking provides general health benefits and helps reduce health risks.
The key to getting a maximum cardio workout from walking is reaching your target heart rate (thr) by walking fast enough, but not to the point where you'll be gasping for air. There are several ways of determining your thr, and the Karvonen Formula is one of them.
One advantage walking has over jogging is the lesser probability of injuries. Jogging is a high-impact aerobic exercise, and it does take its toll on your joints with every high-impact stride you take. With walking, you're less likely to miss days of exercise due to injuries. As long as you're wearing the right walking shoes, walking should be, excuse the pun, a walk in the park.
Once you've taken up walking, it would be a great idea not to stop at 30-minute or 1-hour sessions. Try incorporating walking into every facet of your life. Unless you're working at the topmost floors of the Sears Tower, try taking the stairs instead of the elevator. When dropping mail, walk to the nearest mailbox or post office and save gas in the process. Walking, after all, is a lifetime exercise, and you might as well get the most out of it. It's a win-win proposition anyway, as walking is an accessible, inexpensive, effective and virtually injury-free workout.