Wednesday, April 11, 2012

The role of grativy in pedal stroke

Do you know how to fall? - The role of grativy in pedal stroke.

Dwell on this for a moment: The only reason you have bones and muscles is to interact with gravity. You will find clear evidence of this fact if you've ever tried to run under water.

Gravity is the force that binds us all to the earth, it is present 24/7, 365 days a year and pulls you down towards the center of the earth at a rate of 9.81 m/s2. That is tremendous force. For perspective, think about this piece of trivia: It takes the Space Shuttle 2 million pounds of solid-state propellant and more than 500,000 gallons of super-cold liquid oxygen and liquid hydrogen to break free from the hold of gravity. Gravity never takes a day off (if it did you would notice), which sometimes causes us to forget it's importance in our daily lives. You learn from a very early age the power of gravity as you learn to walk through a series of (semi)-controlled falls. Some of you reading this may have also have a very intimate relationship with gravity if you like dirt jumping as the following rule always applies:

What goes up...must come down, wheels underneath you or not.

So what does this all have to do with cycling?

Once you understand that all movement (on earth) is a destruction of balance (De Vinci's words, not mine) then you start to relize that efficient pedalling is essentially falling forward in a controlled and smooth manner.

Taking something as simple as walking for example. You do not go anywhere until you shift your bodyweight to one foot, and slightly fall forward. The leg movement is a by product of falling, not vice versa.

Let's apply this principle to pedaling. Imagine your pedal cycle as the face of a clock. Studies show that peak power output occurs when the crank arm moves from 3 o'clock through 5 o'clock, which consequently means that 9 to 11 o'clock should be the most relaxed phase for the oposing leg.

From a gravitational perspective, 3 o'clock is the earliest moment when you can apply full bodyweight to the downward stroke of the pedal.

Sounds logical right? It is. However, we can sometimes be guity of forgetting that graivty is the force that drives us, and that muscle function is only to support our use of grativy by moving us into the best position. This forgetfulness can get us into trouble then we start analysing the pedal stoke.

Most pedal stroke advice on the interwebs follows the conventional wisdom -also known as coaching what you see, not what you understand- of applying a pull to the upward stroke of the unweighteg leg to help gerenate more downward force. This is a mistake however, and known as pedaling in a box. Pushing down with one leg as you pull up with the other causes fast phases between 3 and 6 o'clock on the drive leg, and 9 and 12 on the recovery leg, with susequent slow phases through the bottom and top of the pedal strokes respectively. This leads to unnaturally squared corners rather than a smooth continuous circle. The box is also always associated with excessive effort from the rider, and a lop-sided pedal stroke.

So what does this mean for your pedaling efficiency? When you understand that all your effort should be directed at subtly shifting your bodyweight to your downward moving foot from the 3 to 4 o'clock position, you will stop wasting valuable energy trying to pull in a phase of the stroke that us unproductive.

The key take away from all this is that gravity is a FREE FORCE. Until you make it into outerspace, it will never stop pulling you down. It takes much less effort to shift your bodyweight from side to side for a brief moment (during 3-5 o'clock) than it does to try to artificially spin the crank through 360 of rotation, yet both accomplish the same result. Remember your Newton and his apple? You can not fall faster than the rate at which gravity pulls you, thus, why try and pull the pedal down faster, when falling on it with your body weight is as fast as it can go? Said another way; why use effort when you can get the same thing done for free?

Which brings up my final point. Efficient movement is the effective application of technique that allows you to take maximum advantage of the free forces given to you by nature, gravity being the big one. When you regard top athletes in their respective sports, a word that can describe the gamut of them is "effortless". These althetes have found a way to get themselves in the best body position to use gravity, and in doing so have made their sport easy.

I challenge you now to use this knowledge to better your technique. Perception is the first step. Once you learn to feel gravity, movement, and specifically biking, will become easy.


Devin Glage

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