image Karyn Simmonds isn't your ordinary athlete. The 40-year-old mother of one has completed three 100-mile runs, twelve 50-milers, 65 marathons, and countless 10Ks and 5Ks in the past 15 years. She trained for the endurance races, which are usually run on trails in mountainous terrain, by ]]>running]]> 50 to 70 miles per week and riding a stationary bike for 30 minutes four times per week—that is, until she fractured a tibia.

"After my stress fracture, my doctor advised me to walk, so I started walking hills," says Simmonds, who took a six-week hiatus from running in order to heal. "When I got back to training, I realized that I could walk hills faster than I could before. Actually, there was a time when I was power walking in a race past people who were running. I decided then to train for walking, too."

Why Walk?

While many athletes view walking merely as a means of transportation, a way to get from here to there, what they don't realize is that it can actually be a complement to their vigorous training programs. In fact, research has shown time and again that walking is comparable to other forms of exercise in terms of cardiovascular benefit. For example, a study conducted by Bill Byrnes, PhD, professor of kinesiology at the University of Colorado, compared the cardiovascular benefits of people who ran, walked, or did aerobics. They all exercised at 75% to 85% of their maximum heart rate, and each group saw almost identical improvements in aerobic fitness.

Another study on cross training showed similar results, supporting what is called the "independence of the exercise mode effect." "Basically, this means you can select any aerobic activity or mode, and if you perform these two different activities at the same intensity level and for the same duration, you will get the same improvements in cardiovascular fitness," says Michele Olson, PhD, professor of exercise physiology at Auburn University and author of the study. But both Byrnes's and Olson's studies showed something else: the runners experienced significantly more, and more serious, musculoskeletal injuries than the non-runners. In fact, in Byrnes' s study, the running group missed 11 days due to injury, while the walking group missed only 1.5 days.

Why the difference in injury rates? Mainly it is because of the force with which you hit the ground when running versus when walking, says Mark Fenton, five-time national race walking team member and former editor of Walking magazine. While the impact force of running is roughly three times that of your body weight, the impact force of walking is just one and a half times your body weight—not a difference to sneeze at.

Better Running Times?

It's true that walking can improve your level of fitness and help reduce the amount of time you spend pounding the pavement (or grass or trail), taking the pressure off your joints. But can it help you with your running times? According to Olson, the answer is yes.

"There's an old saying in exercise physiology that if you mix training, you get mixed results," she says. "If you want to excel at running, you'd want to stick to activities that closely mimic running, such as interval training and sprinting, so that you continue to develop that skill. Walking would fit in with that."

Simmonds can testify to that. She says that walking has not only increased her overall fitness, but it has also helped her race times. "There's a race I've done three times—the Quadruple Dipsy. It's 28.4 miles and goes up and over two mountains. The times I had walking in my training, I won the races and was significantly stronger than the time when I was only running (for training)."

Take a Walking Break

So if you're suffering from overuse injuries but don't want to forego exercising every day, try incorporating walking into your program. At the very most, you'll improve your health, well-being, and race times. At the very least, you'll give your knees (and hips and ankles) a much-needed break.

How to Make Walking a Workout

"National caliber race walkers routinely train at 7 mph or faster and get their heart rates up over 85% of max," says Mark Fenton, a five-time national race walking team member. "With a normal walking gait, without any technique modification, you can't get above about 60% to 65% of max, because most people top out at about 4.5 miles per hour."

In other words, if you want to walk at speeds high enough to get a great workout, you need to work on your form. Follow these four tips, and you'll be on your way:

  1. Maintain an upright posture. Don't lean forward at the waist; look forward, not down at the ground.
  2. Take quicker strides, not longer ones. To make it a real workout, you have to stride between 140 to 150 steps per minute.

    Tip: Try counting steps for 20 seconds. You should be doing about 50 steps in that period.

  3. Bend your arms. Use a compact and quick arm swing; hands should trace an arc from your waistband at the back to chest height in front. (Taking a longer arm swing will actually make you take slower steps.)
  4. Push off your toes. At the end of each stride, aggressively push off the ground with your toes.

No-frills Drills

The Straight-away

At your local track, jog along at a slow pace around the turn. When you get to the straight-away, break into a fast walk, trying to stay at the same pace as your jogging. When you get to the turn, jog again.

Do two to three laps. Next time out, make it four laps. Build up to six laps.

When you feel comfortable doing six laps, start to extend the drill to an entire lap of walking for every half-lap of jogging. Build up to the point (over a couple of weeks) where you can do six to eight laps of that. When you feel comfortable, move up to walking an entire half-mile or mile at a time at a brisk tempo. This could take as long as five or six weeks.

The Prance

Start at one end of the track. For 10 seconds, walk with the shortest, quickest steps you can take. Try to take three or four steps in one second, which would put you at 180 steps per minute. If you can do this, then getting to 150 steps per minute (the goal set in the Straight-away) won't seem that extreme. Rest for a minute, then repeat a half-dozen times. The goal here is to be able to go a half-mile or a mile at a time at 150 steps per minute.