I've been working pretty hard lately on my daily 7.5-mile commute, so yesterday afternoon I decided to dial it down a notch and just enjoy the ride home. Much to my surprise, my time actually improved. This suggests to me that I've been wasting a lot of effort, and that I need to pedal smarter, not harder. Any tips? Just for context, the ride is quite hilly, with about 400 vertical feet of climbing in each direction.
-lady macsquish
Dear Lady:
Funny you should mention this observation. Not only have I seen this advised and suggested in numerous places, I have been trying it myself lately. And I'm getting the same results you are. In most flattish places on my commute I'm dropping back a gear and staying at about the same speeds or going a little faster. Descending I'm backing off two with no drop in speed. Climbing I'm relaxing by a gear in some places but I'm also a masochist and enjoy pushing it on hills. Little bumps are easier to get over at speed since it's easier to keep spinning. Result: my cadence is up, my speed is up, my heart rate is up. I'm considering the semiultimate experiment for this weekend: riding my favorite so called time trial route. My guess is I will be down one or two gears and be at or better than my best time. Look for the report.
As far as hows and whys, I am not immediately able to lay my hands on the best explanation I recall reading on the benefits of spinning — riding so that the cadence, or revolutions per minute of the pedals, is higher. But since I wanted to provide someone else's made up explanation rather than my own, I found this at trifuel.com, a site for people way too interested in these sorts of things and who don't think they have to address lay people (in other words, you're on your own with most of the jargon):
When you pedal a bicycle, your muscular system produces power to propel the bicycle and your cardiovascular system delivers oxygen, fuels the muscles, and removes waste products such as lactic acid. Selecting your optimal cadence is a matter of keeping these two systems in balance. The optimal balance is different for each person.
Spinning at higher cadences reduces the watts-per-pedal-stroke, a measure of the force required to produce a given wattage. This makes the workload more tolerable for the muscles. Most experts believe that this is because fewer fast-twitch muscle fibers must be recruited to create the high torque levels required at low cadence. Pedaling with a too-low cadence increases reliance on fast twitch fibers, causing premature lactic acid accumulation, which makes your legs burn.
Pedaling with high cadence, however, does waste some energy. Imagine setting your bike up on an indoor trainer and cutting off the chain. If you spun 100 rpm, the workload would be zero watts, yet your heart rate would elevate significantly above resting. Just moving your legs fast does use energy. Research has consistently demonstrated that cycling at 40 to 60 rpm generates the lowest oxygen consumption for a given wattage. Pedaling at too high a cadence overloads the cardiovascular system's ability to deliver oxygen to the muscles. The most obvious symptom of this is ventilatory distress.
High-cadence pedaling works your cardiovascular system more, but reduces the relative intensity of the leg muscles. The key, then, is pedaling with enough cadence to keep your watts-per-pedal-stroke at a level that your muscles can handle, but at a cadence that will not overload your cardiovascular system. The optimal balance is different for every rider.
I will translate one phrase: "ventilatory distress" means you can hardly fuckin' breathe. What I get out of the rest of this passage is that cadence is a tradeoff between pushing your legs and pushing your heart and lungs. And another thing: there is not a direct correlation between higher cadence and higher efficiency.
Other sources, such as Bicycling Magazine's 1,000 All-Time Best Tips, point out that becoming comfortable with higher cadences in lower gears can help riders become more comfortable with higher cadences in higher cadences. So keep trying it, see what happens and keep us posted. I'll do the same.
Yours in velophility,
Cycledork
1 comment:
Now that you mention it, I've recently noticed that it's *faster* to spin up one of my steepest hills rather than standing on the pedals. Man, it does make me huff and puff, though, which is in line with the explanation here - that I'm essentially transferring the burden from my legs to my lungs.
Post a Comment