By Bonnie Stein, M.Ed.
If you jumped on the walking bandwagon earlier this year, as a New Year’s resolution, was your goal health or fitness? If you’re not sure there’s a difference, think of Jim Fixx, the running guru who died of a heart attack. He was fit, but unhealthy. You can also be healthy (free of disease) and not very fit.
Since January I’ve noticed many more strollers in the neighborhood parks. Emphasis on the stroll. While strolling (loosely defined as a 20 minute mile or above) will give you some health benefits, it does little for your fitness. For most of us it’s a walking pace at which you wouldn’t “break a sweat.” One woman asked me, “is it OK to walk slow enough so that I can still read while on the treadmill?” (She set the treadmill for 2.2 mph.) My answer was, “It’s OK if you want to get more out of your reading than your walking.”
Surely, walking a 2.2 mph pace is better than doing nothing. Since it’s higher up on the energy expenditure scale, you’ll burn more calories than walking at 2.1 mph and even more than standing still. Yet, at that pace, about 27-28 minutes per mile, unless you are extremely out of shape to start, you’ll be doing little to improve your fitness level.
Your walking workout should be designed differently depending on the results you wish to achieve. Health benefits such as lowered blood pressure and a raise in HDL (the good) cholesterol occur with any regular walking program, even strolling. However, cardiorespiratory improvement, as measured by maximum oxygen uptake, and serious calorie burning will occur when the walking intensity is increased so that the subject is exercising in the target heart rate zone, defined as a heart rate which is 60-90% of maximum.
The first study to measure VO 2 Max improvement of walkers was done at Dr. Kenneth Cooper’s Institute for Aerobic Research in 1990 by Dr. John Duncan. The results of the study compared the benefits of different walking intensities with results of previous running studies.
Three walking intensities were studied: strolling (20 minutes per mile), brisk walking (15 minutes per mile), and aerobic walking (12 minutes per mile). The study involved healthy, but sedentary 20-40 year old women. All women walked five days a week and all walked three miles per session. The only variable was walking intensity. The 102 participants were divided into four groups and labeled the strollers, brisk walkers, and aerobic walkers. The fourth group was sent home to continue being sedentary for the duration of the study.
To sum it up, the study revealed that walking intensity indeed does make a difference, both in terms of cardiorespiratory improvement, as well as the amount of calories burned per exercise session. As measured by maximum oxygen uptake, the strollers improved fitness by 4%, the brisk walkers by 9%, and the aerobic walkers by 16%. The strollers exercised at 56% of maximum heart rate, the brisk walkers at 67% (the low end of target heart rate), and the aerobic walkers at 86% of maximum heart rate (the high end of target heart rate.)
Over the 14 week study, only the aerobic walkers improved in fitness similarly to an exercise runner. The aerobic walkers were not racewalkers although they did utilize the bent arm technique of the racewalker. I have found that even very fit runners can achieve upper levels of target heart rates once they’ve mastered racewalking techniques. This makes racewalking an ideal cross training sport for runners. Walking at high intensity also serves as a worthwhile exercise for running related injury recuperation. None of the exercise walkers at any pace, incurred an injury during the study.
The terms “strolling, brisk walking, and aerobic walking” refer to pace as far as I’m concerned. In my experience, anyone can be a racewalker by incorporating racewalking techniques. A very overweight, beginning exerciser can start out at a strolling pace, but by using racewalking style, will more easily move to the brisk walking pace as fitness improves. Likewise, by utilizing racewalking technique, the 15 minute mile brisk walker will be able to have a more dynamic walking workout and increase his pace more easily as his fitness improves.
The aerobic walker, referred to in the study, is better described as a high intensity walker, since some out-of-shape walkers will be able to attain aerobic or target heart rate intensity with a fairly slow pace. Furthermore, if you are just beginning a walking program and you try to walk at a 12 minute mile, you will most likely be beyond your target heart rate zone; thereby not receiving the maximum benefits of your walking workout. Heart rate is the way to keep track of intensity either by taking your pulse, using a heart monitor, or utilizing perceived exertion (it should feel somewhat hard.)
Whatever your pace, decide what you wish to achieve with your walking workout, from health benefits to losing weight and fitness improvements to competition aspirations. As running coach Roy Benson often says, “effort is the answer.” And so it is true with walking.