Tuesday, June 30, 2009

Improving your Cycling Efficiency with Video Analysis

The Tour de France is the ultimate in road cycling competition. Covering 3500 kilometers (2187 Miles) over 22 days, the event tests the cyclists mental and physical strength. To complete in this grueling endurance test, the athletes need to be in peak fitness, but they also need to ensure their technique is as efficient as possible. Energy can be preserved, injuries prevented and more power created with good technique.

The best way to evaluate your cycling form is with a few appropriately positioned video cameras. Although you may encounter flats, up hills and down hills on your bike ride, the general position for cycling is the same and therefore you can benefit greatly by improving the efficiency of your cycling power stroke. Although there may be various inclines and flat sections, your position during the ride is generally constant, and therefore you can benefit greatly by improving the efficiency of the cycling power stroke. The power stroke is the cycling pedal stroke including the push down and pull up of the pedal.

Assume you are sitting on the saddle of your bike with your upper body still (as it should be). The power required to turn the pedals over comes from the muscles in your hips, thighs and calves. This power is transmitted to the pedals, and from there drives the cogs and so on, turning the rear wheel.

Now for some basic physics. In order to push down on the pedal or pull the pedal up with the greatest force and the most efficiency, you will want your muscles to generate a force that pushes or pulls directly down or up on the pedal (depending on whether you are in the down stroke or up stroke of the pedal motion). Your hips, knees, and feet all need to be aligned correctly to produce a purely vertical force on the pedal.

In the image above we have the side view of a cyclist. The cyclist cannot use his thigh muscles to push directly down on the pedal but we can see that his knee is directly above the middle of the pedal which will allow him to push down efficiently as he straightens his knee. The force (red line) from his thigh muscles will be transmitted along with the force from the calves to the pedal. If his knee was in front of the pedal he would be wasting energy pushing backward, and if his knee was behind the pedal he would not be able to produce as much downward force because his knee would straighten too early.

A camera looking from the front would give us another important perspective. With this angle we will be able to see whether the hips, knees and feet all line up with the center of the pedal. Once again we want all the joints to align with the center of the pedal, so that all the force is generated directly through the pedal. If the cyclist's knees pointed outward rather than forward, he would be losing efficiency by generating a force that is not directly in line with the pedal. If he did this, he may also suffer from injuries as he attempts to maintain the same speed. He will need to recruit different muscles or strain ligaments and tendons to make up for his lack of efficiency

Video analysis of your cycling technique is easy to do with a couple cameras and a stationary bike. Below are 2 great examples. A side on view allows the cyclist to evaluate his position on the saddle as well as his knee and foot position.

A front on view allows the cyclist to check the forward alignment of his hips, knees and feet.

This cyclist looks to have good biomechanics and an efficient pedal stroke. For a more detailed analysis you can also use video analysis software to calculate the angles and accurately measure the positions.

Lance Armstrong will be in action again this year at the Tour De France and we look forward to seeing what he can do. Lance has spent many hours in testing wind tunnels measuring his bike performance, but we are sure he also uses this data to fine tune his biomechanics for maximum efficiency. So get out your video cameras and film yourself in action.

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