Treadmill training: In mid-May, newspaper headlines trumpeted the news: treadmills are the best exercise device for individuals interested in burning calories and losing weight, beating stationary bicycles, stair machines, rowing devices, and cross-country ski machines by a whopping margin.
As a result, people who trained in gyms and clubs began to cast a cold eye on stair steppers, bikes, and rowers and somewhat furtively began trudging along on treadmills in hopes of shedding extra pounds of blubber.
The actual research with the good news about treadmills - and the less heartening words about the other contraptions - was carried out at the Medical College of Wisconsin in the United States ('Energy Expenditure with Indoor Exercise Machines,' Journal of the American Medical Association, vol. 275(18), pp. 1424-1427, 1996). In the study, 13 healthy young volunteers (eight men and five women) completed exercise tests on a treadmill, a stair stepper, a rowing ergometer, a cross country skiing simulator, a regular exercise bike, and an exercise bicycle equipped with bars which worked the arm muscles (an Airdyne). Subjects were about 30 years old, were fairly lean, and were moderately fit (with average VO2max of about 50 ml/ kg.min).
In order to become more familiar with each machine, each subject worked out on each exercise device at least eight different times (workouts lasted about 15 minutes) during a four-week preparatory period. In this same time period, subjects learned how to use ratings of perceived exertion (RPE) to evaluate the intensity of their workouts. The RPE scale ranges from 6 to 20, with 11 being a 'fairly light' workout, 13 a 'somewhat hard' session, and 15 a 'hard' bout of training.
Before the actual tests, there was a five-minute warm-up, a two-minute rest, and then three five-minute 'stages' of exercise at RPEs of 11, 13, and then 15, with two minutes of rest between each stage. Testing on the six different devices was carried out on separate days. No caffeine could be ingested during the three-hour period before testing, and no food could be taken within two hours of exercise.
Pity the poor stationary bike!
As mentioned, exercise on the treadmill tended to produce much higher rates of calorie burning. During 'hard' exercise at an RPE of 15, treadmill walking or running burned about 850 calories per hour, against around 700 or so for the stair stepper, rowing ergometer, and Airdyne. The cross country ski machine checked in at 650, while the lowly stationary bike averaged only about 600 calories.
During 'somewhat hard' exercise at an RPE of 13, treadmill exertion topped out at 700 calories per hour, while stair stepping settled at 627, rowing reached 606, skiing sank to 595, Airdyning to 509, and regular biking to just 498.
And treadmilling racked up greater caloric expenditures even during 'fairly light' efforts at an RPE of just 11. At such intensities, treadmill exercise expended 550 calories per hour, compared with 500 or so on the stair machine, rower, and ski device - and just 350 to 380 on the bicycle and Airdyne.
Is the treadmill really the best indoor exercise device, as the calorie-burning data suggest? Well, that depends on lots of things. First of all, as Anne Zeni, one of the Wisconsin researchers points out, the results of the research might not apply to the elderly or to people who are out of shape. Conceivably, non-fit people might actually burn more calories on a stair stepper or rower than a treadmill, since they're much less familiar - and much more uncomfortable - with climbing steps and rowing, compared to walking or running.
In addition, although calorie-burning rates differed, none of the exercise devices really fared badly in the tests. 'All of the machines can be used successfully to maintain or improve fitness,' notes Zeni.
Finally, treadmilling enjoyed an important 'edge,' compared to the other modes of exercise utilised in the research. As Dr. Zeni points out, people begin walking and running at the age of two and are usually completely comfortable with both activities in adulthood. Cycling, rowing, skiing, and stair climbing are simply less familiar - and less comfortable activities. Thus, in spite of the habituation period which called for each study subject to work out several times on the various exercise devices, most of the research participants probably still felt more relaxed and confident walking or running, compared to rowing, biking, skiing, or climbing. This created a situation in which 'hard' efforts could be reached at lower intensities and lower heart rates on the non-treadmill exercise machines, leading to lower calorie burning.
Experience counts
Of course, that scenario could be totally turned around if athletes had greater experience with the alternative exercise devices. For example, someone who trained four to five times per week on a stair stepper and became a skilled stair machiner would gradually increase calorie-burning rates until they equalled - or even exceeded - the rates associated with treadmill walking/running.
And of course that means that athletes, even ones who want to burn mega calories during workouts, shouldn't avoid alternative exercise devices. Having to confine one's workouts to the treadmill might actually decrease one's workout frequency if treadmill sessions are viewed as boring, and - as mentioned - calorie-burning rates will gradually increase on the other pieces of equipment.
In addition, each device has its own unique merits. Rowing machines are great for building upper-body strength and accentuating bone fortification, along with their positive impact on cardiovascular development. Stair machines build hip- and leg-muscle strength and probably enhance running economy. Ski machines are terrific for stimulating the cardiovascular system without giving the musculoskeletal system a thorough pounding. And bicycling, despite its low rating in the Wisconsin research, can provide very high-intensity workouts and has actually boosted running capacity in several different scientific studies.
The bottom line? Do what you like to do - and utilise the exercise machines which are most likely to help you in your particular sport. If you do that, there's no way anyone can say your exercise machine is 'worse' than any other.
Owen Anderson