While they’re both technically ‘bikes’, the airbike and the bike erg apply a very different stimulus to the body. And with a different stimulus comes a different adaptation, and different training effect for each.
Let’s explore the differences in the physiological effects these two machines can have on the body, and how coaches and athletes can use them both to their advantage.
Not this is not a product review (comparing the two pieces of machinery), but a training effect review (comparing what effect each has on your physiology). Airbikes come in many forms, the Rogue Echo Bike, the Assault Bike, and numerous (virtually identical) versions of the same device.
There’s a very basic training principle that will make everything we discuss here easy to understand. Whatever the limiting factor of a training session is, that is what that session will improve. For example, if your ability to perform a heavy deadlift is limited by your strength, that heavy deadlift will make you stronger. If your ability to do lots of push-ups is limited by your localised muscular stamina, doing high reps of push-ups will improve your stamina. If long runs are hard because you get out of breath, doing a long run will train your ability to not get out of breath.
This is know as ‘supercompensation’, and is our body adapting so that we’re better prepared for a similar bout of exercise in the future.
We’ll keep revisiting this concept as we go.
A primary major difference is obvious at first glance. An airbike uses both the upper and lower body, while the bike erg is predominantly lower body.
To understand the training effect this has on the body, we need to understand some basic physiology. Our blood transports oxygen and nutrients (fuel) to the lungs and muscle tissue, and deliver hydrogen ions (which cause the ‘acid burn’ sensation of high intensity anaerobic exercise) to the kidneys to be buffered (broken down).
While our blood is highly efficient at these roles, the more muscle tissue we’re dealing with the more likely we are to reach our physical threshold.
Put simply, there’s only ‘so much blood’ to go around. Using both the upper and lower body on the airbike taxes our circulatory and respiratory systems more. And as we’ve discussed, whatever the limiting factor of an exercise session is, that is what it will improve. The full body movement of an airbike is hard to beat as a cardiorespiratory conditioning tool.
This is an example of ‘blood shunting’, where blood is directed to the muscles that require it. In many movements and exercises, there may only be a small handful of muscles that need blood. On the airbike however, the blood is required in the massive muscles of the lower body, as well as in both the push and pulling muscle groups of the upper body.
By contrast, the bike erg requires only the lower body musculature to be served. As a result, while the airbike results in a much higher power output (more on this soon) due to the recruitment of more muscle groups to turn the fan, time to exhaustion is generally shorter than it would be on the bike erg.
On the topic of blood shunting, it’s worth exploring the effect that each piece of equipment would have when used in conjunction with another movement in a multi-modal style session. We can use a knowledge of blood shunting to tax the cardiorespiratory system by alternating between different movement types, therefore forcing a rapid redistribution of blood flow as we alternate. If we look at a movement like a muscle-up or a hang power clean and jerk for example (both relatively upper body dominant movements), we would experience a very different effect by pairing these with the different bike types. Paired with the bike erg would see an effective cardiorespiratory training stimulus (as there is little interference between the two movements. Paired with the airbike however would force a decrease in intensity, as the upper body inclusion of the airbike would pre- fatigue the arms for the muscle-up / hang power clean and jerk, resulting in a lower work rate. As such, the session would train localised muscular stamina (as this would be the limiting factor), rather than cardiorespiratory endurance.
Let’s explore this concept further, and go back to comparing the two machines in isolation.
Performing a sustained high intensity piece on each piece of equipment will very quickly reveal a major difference. A relatively well balanced individual (an ‘all rounder’) will complain about ‘leg fatigue’ on the bike erg, and ‘being out of breath’ on the air bike. This gives some clues as to the limiting factor (a reminder, the limiting factor tells us what it is that the exercise is training).
The limiting factor on the bike erg is localised muscular stamina – the ‘fatigue resist-ability’ of the legs. Therefore, the bike erg will train the ability of the legs to resist fatigue. This is very much a peripheral training effect.
The limiting factor on the airbike (due to its ‘full body blood shunting’ nature) however, is not peripheral localised muscular stamina, but a more central, systemic fatigue of the entire cardiorespiratory system. Therefore, the air bike will train this cardiorespiratory system.
Now of course, nothing exists in isolation, and this is definitely a highly simplified explanation. The bike erg will doubtless also train the cardiorespiratory system, and the airbike will certainly train leg stamina. But the percentage of each is reversed.
That is, the bike erg is 60% legs and 40% ‘heart and lungs’, whereas the air bike is 40% legs and 60% ‘heart and lungs’. Of course, these numbers are very unscientific and are just subjective estimates based on the feel of each machine.
In terms of pure, short-term power production (generating a very high output, or a high level of watts), the full body recruitment of the airbike comes out on top. As a method of testing anaerobic work capacity for efforts of under 60 seconds, the airbike unrivalled.
So which is better? It’s like asking what is better out of squats and pull-ups. They’re completely different, and they train different things.
Remember the supercompensation principle, and also the principle of specificity. Whatever the limiting factor of an exercise, or a training session is, that’s what it will train. So if you want to train the limiting factor of the airbike, that’s what you should be using. If you’re looking to train the limiting factor of the bike erg, use that.