No need to ditch the elliptical......(long)

This is a new blog I just posted today. Yeah, I write long.

Is there one type of cardiovascular exercise that is better than all others? Does it make a difference what cardiovascular (aerobic) exercise you do?

In general, the answer is “NO”. When it comes to aerobic exercise, HOW you do it is much more important than WHAT exercise you do.

The primary training goal of all aerobic exercise is to improve the function of your cardiovascular system, i.e. to improve your ability to deliver oxygenated blood to the tissues where the oxygen is used to create energy. This is referred to as increasing your maximum aerobic capacity, or maximum oxygen uptake (VO2max). The higher your cardiovascular fitness level, the more oxygen your body can use to create energy via the aerobic metabolic pathways.

For people looking to lose weight, aerobic exercise, in addition to the training effect, contributes to maintaining a calorie deficit by burning a large number of calories at one time.

The higher your VO2max, the higher intensity you can sustain during your workouts. And the higher intensity you sustain, the more calories you will burn, since caloric burn is the direct result of workout intensity X body wt.

While any activity can burn calories, in order to achieve a training effect, aerobic exercise must be performed at a minimum intensity, frequency, and duration. For sustained results, the intensity needs to be at least 60% of VO2max, for 20 minutes a session, three days per week. (This is not set in stone, but is still the generally accepted guideline).

If the activity meets the above intensity, frequency, and duration guidelines, then ANY cardiovascular exercise will yield the same general cardiovascular training benefits. And if you are working at the same intensity level, ANY cardiovascular exercise will burn the same number of calories.

The idea that “doing ‘Exercise X’ burns twice the amount of calories as a treadmill” for example, is physiologically impossible. In order to “burn twice the amount of calories”, you have to be working twice as hard.

While hypothetically doing any aerobic exercise can result in similar fitness and weight loss benefits, there are some practical differences between aerobic exercises. There are some movements that are inherently more intense, some movements that “feel” easier when working at higher intensities, some that require more adaptation before one can work harder, and some that require a greater skill level.

One of the reasons why running is such an effective exercise—both for conditioning and weight loss—is because, even at slow speeds, running is a relatively high intensity exercise. The dynamic motion of running also does not focus the effort on one small area of muscle, so musculoskeletal adaptation tends to be faster. When compared to other types of exercise, more people find that running—even though the actual intensity of effort is higher—“feels” less hard than other modes of exercise. (Results of research in which subjects self-selected intensity based on a given perceived exertion level).

This contrasts with activities such as cycling and stairclimbing. These activities have smaller movements, and concentrate the resistance load on a smaller muscle mass. Because of this concentration, localized muscle fatigue is usually a limiting factor for beginning exercisers rather than intensity itself. Both intensity and duration of effort are limited by muscle fatigue. As a result, the exercise—esp stair climbing—“feels” much harder, but, in fact the actual workload (oxygen uptake) is significantly less than that achieved by running.

Now before the cyclists and stepmillers get out the pitchforks and torches, let me emphasize that this does not mean that cycling and stairclimbing are “inferior” exercises. Far from it. It just means that when you add these activities to your routine, it takes more time to condition the muscles and to build up the strength and endurance necessary to push yourself to the same high level as running. It also means that you cannot rely on factors like muscle fatigue or sweat to evaluate the true intensity of the workout—at least not at first.

Another example is swimming. Swimming is an excellent conditioning exercise. However, for swimming to be most effective, one must not only build up muscle endurance, esp in the arms and shoulders, one must also take the time to develop proper stroke mechanics.

All of these exercise movements—cycling, stairclimbing/stepmill, swimming—can be highly effective for both cardiovascular conditioning and weight loss. They just require a little more time and dedication to develop the techniques and the movement-specific muscle conditioning and endurance necessary to achieve optimum results. This category also includes cross-country skiing and rowing.

Walking is an exercise that has its own limitations. Walking can be an excellent exercise because it is easy to do, safe for anyone, and requires almost nothing in the way of facilities or equipment. However, walking is inherently a low-intensity exercise. Even at speeds that most people would consider “vigorous” and close to their comfort limit – eg. 4.0-4.5 mph—walking intensity is less than 5 METs. Again, any activity is positive and burns calories. However, walking may not be intense enough for younger or fit individuals to experience a training effect—and the calorie burns are relatively low. These limitations can be offset by incline walking, vigorous arm swings (or poling), and learning race walking.

And then there are elliptical cross trainers. Elliptical cross trainers are somewhat of a “hybrid” activity—the dynamics of the movement often result in HR and VO2 levels similar to running, but with less impact (in fact, in another study which looked at actual VO2 achieved when subjects self-selected the workload based on perceived exertion, the Cybex Arc Trainer narrowly edged out running as the highest actual exertion level).

Elliptical cross trainers also have a large range of resistance levels. Most elliptical can be performed at very low levels—comparable to slow walking—but also have workload capacity that is beyond the practical physiological range of human beings.

I sometimes read remarks such as “elliptical are for grannies” or “elliptical aren’t effective because the momentum does all the work”. That may be true for some crappo infomercial piece that doesn’t have any way to increase resistance, but it’s a really unintelligent thing to say about a commercial cross trainer. Like many pieces of equipment, YOU have to supply the effort. Since commercial cross trainers have a workload capacity that exceeds human physical ability, there is no reason why someone can’t push themselves as hard as they need or want to on an elliptical—to max effort if necessary. If someone is doing a mediocre workout on a cross trainer, it’s not the fault of the machine or the exercise—it’s the fault of the user.

The last part that has to be addressed when you evaluate the effectiveness of any new piece of cardio you try out is the concept of training specificity. This simply means that training effects tend to be specific to the type and manner of exercise performed. While all types of cardio result in similar GENERAL cardiovascular training effects, movement efficiency is limited more to the specific exercise you do on a regular basis. Put simply: running does not prepare your muscles for doing a Stepmill. If you always run and then one day try something like a Stepmill, you will likely struggle at first and think “man, this exercise is really kicking my but”. However that perception of being more intense is due more to localized muscle fatigue than anything else. In fact, if we were to measure your VO2, we would probably find it to be noticeably lower than when running on the treadmill at a similar level of perceived exertion. I do the Stepmill only occasionally – not enough to really condition my muscles for it—and I know that, even though my legs hurt a lot more and it is a struggle to do 15-20 min (instead of 30-40 running), my VO2 on the Stepmill is at least 20% lower than what I can sustain while running. So even though I feel like I am working harder, I am actually burning a lot fewer calories per minute. (Now, if I trained regularly on the Stepmill, I would gradually increase my leg strength and endurance for that modality, and eventually be able to reach the same VO2 on both).

Again, my point is NOT to downgrade ANY form of cardiovascular exercise—my position is exactly the opposite. I just think it is important to know the facts so you can make an informed judgment.