ARTICLES, TIPS, TRAINING & GENERAL ADVICE

One Leg At A Time

by Brad Hefta-Gaub, December 30, 2007

One Legged Intervals

What are one-legged intervals? Here’s a quick explanation of what they are and how they may help you in your cycling, triathlon, and maybe even your run training.

Pedal Stroke

First of all, a little bit of background on pedal stroke. We all learn early on (when we first learn to ride a bike) that the majority of our power comes from pushing our legs downward on our pedal stroke from the 2′o’clock to the 6′o’clock positions on a pedal stroke.

The Down Stroke

It is natural to feel this downward motion in each of your legs as they move from the top most position to the bottom most position in the pedal stroke. Since your legs are evenly spaced (exactly 180 degrees apart around the circumference of the circle which is your crank) you can easily generate sufficient power to pedal a bike by only applying this downward motion to each leg as you pedal.

In the diagram above and below, I’ve marked this portion of your pedal stroke in red. Some studies suggest that as much as 65% of the average cyclists power comes from this portion of the pedal stroke. However, you have additional opportunities to add power as your pedals and feet move the remaining distance around the circle.

The Scrape

The second easiest part of the stroke to learn is the additional backward thrust that can be added to the pedal as you move from approximately 5′o’clock to approximately 7′o’clock. I’ve heard this motion being described as wiping mud off your shoe, and I think that’s a very good description of the experience.

I’ve colored this portion of the pedal stroke in orange, and it is often included in power calculations for the down stroke, as the muscles being used are primarily the same although the foot angle has changed and your calf muscles are more activated during this portion of the stroke.

The Up Stroke

If you are using clip less pedals (Note: I’ve never understood why the kind of pedal that you clip into is called clip less) then you have an opportunity to also add power to your upstroke. I’ve colored this section yellow, and it is estimated that as much as 25% of your power can be contributed from this portion of the stroke. Finally across the top, colored in green, you can contribute about 10% additional power.

The Advantages of a Full Pedal Stroke

There are many advantages to be gained by learning how to make “good circles” as you pedal. When you consider the fact that typical pro cyclists are only adding 65% of the power during their down stroke, there’s at least 35% additional power waiting to be had if you can learn to use the remaining portion of your pedal stroke.

However, you also gain the advantage of using more, different muscles, and that will allow you to prevent fatigue on longer of faster rides. Finally, these different muscles have different abilities to generate power at different cadences, and different abilities to withstand lactate acid build up, and so if you can get good at using all of these various muscles you will have the ability to utilize different pedaling strategies over different terrains or race circumstances further increasing your advantage.

Making Good Circles

So how do you learn how to make good pedal strokes - good circles?
Well like everything, practice is the key. There are several drills that can help you, one of which is one-legged intervals.

What is a one-legged interval? Well, it is exactly what it sounds like: pedaling your bike with only one leg. Most people do this on a trainer in their home, probably because it can look kind of silly. Basically unclip one shoe, and pedal for 30-60 seconds.

Feedback from Your Pedals

While you do this pay particular attention to applying power throughout the full circle of the stroke. Don’t just “push down” and let the crank coast around to 2′0′clock. Scrape your foot across the bottom of the circle, pull up from 7 to 10′o’clock, and make a point to draw your leg up and over from 10′o’clock to 2′o’clock. If you are not making a full circle you will get feedback from your bike. If you are pushing too hard and not pulling enough, you will feel the crank “ease” as tension is removed from 7 to 2 o’clock.

One legged pedal also has the obvious benefit of allowing you to concentrate your muscular development on one leg at a time. You will probably notice pretty quickly the first time you try this exercise that it’s a lot easier to do with one of your legs than the other. You probably never realized you had a dominate leg, because when you’re pedaling with both legs your dominate leg masks the slight weakness in your other leg.

Riding Fixed Gear

Another tool in learning to make good circles is riding a fixed gear bicycle. As I’ve discussed in the past, fixed gear bikes force you to keep your legs moving and as a result work to teach your muscles and nervous system to work in unison to move those legs in good circles.

Go Ride: One Legged

When I do one-legged intervals, I usually try to go for 1/4 mile per leg. Then about 1/10th mile with both legs, then switch to the other leg and repeat. I like to add these in for about 4 to 8 repeats per leg when I’m on my LSD rides. You might want to practice a couple times on a trainer before you try it on the road. If you do, do these repeats out on the open road, expect a few strange looks from pedestrians and other cyclists.

• “The Lance Armstrong Performance Program” by Lance Armstrong and Chris Carmichael
• “Serious Cycling” by Edmund R. Burke, PhD

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