Thursday, July 23, 2009

Legs Versus Heart...Part II

The question of cadence might be a question of your strength...Heart or legs?

Many riders train with wattage these days. Power is defined as work over time. Work is defined as force times displacement. Simplified, the two components of power is force and time. P=F/t.

So a rider who pushes a big gear can produce a large force per pedal stroke. They will, however, pedal slowly. A rider who "spins" will produce less force per pedal stroke but will bill pedal faster. Therefore it is possible for both of those riders to produce equal power. Which is more efficient?

Spinning at a high cadence will be more likely to increase your heart rate higher than the gear masher. The gear masher will produce more muscular fatigue than the spinner. What works for you?

I started racing as junior and was forced to use junior gears at times (not the same of today when it is forced even when a junior races senior races.) So that taught all of juniors to spin a little faster. I then went through a phase of mashing gears. Never getting out of the big ring. Then I went back to spinning, but I sucked at time trialing. So much of my training this year (now that I have a power meter) was to figure this out for myself.

My first clue was when I got my VO2max measured. It was nothing to publish. It was above average for America but probably below average for endurance athletes. It was just below 59 (done in February). This told me I didn't have the lungs and heart like a Lance Armstrong that could produce such a high cadence and still hold a conversation.

When practicing my TT intervals recently, I discovered I was very comfortable (comparatively) at a low cadence and big gear. I was also able to maintain a higher speed. But I couldn't accelerate very fast. It was more like a diesel engine. It took me awhile to get up to speed but it was easy to maintain it.

So here is what I discovered. When time trialing, or riding at a steady pace by myself (solo break), I am better applying the large force with a low cadence. When pack riding though, my cadence needs to be higher to be able to react to accelerations. Another thing to think of with pack riding is the ability to recover. So the higher cadence works well in the pack or pace line because you will have chances to recover and lower your heart rate and it is important to keep your legs as fresh as possible.
Post a Comment