Technique: A new spin on pedalling slow
By Nick Morgan, Cycling Plus | Monday, April 20, 2009 2.00pm
Control the urge to spin fast – for longer distances a slower pedalling cadence is more efficient www.robertsmithphotography.co.uk
The trend for pedalling rates has, for the past 10 years or so, been all in one direction: faster, faster, faster. Seeing a dominant Lance Armstrong dancing up mountains with pedals spinning at incredible speeds has been one factor, but science has also played a role, with studies suggesting faster cadences lead to better results.
But one man who remains unconvinced is Dr Ernst Albin Hansen from the Norwegian School of Sport Science in Oslo. A former Danish national team cyclist, Dr Hansen has spent much of the past decade analysing pedalling rates. In particular he has compared the cadence people naturally choose with the optimal cadence in terms of energy expenditure.
His work suggests the ‘pedal faster’ mantra is too simplistic. In certain situations a higher cadence may be better, but in others it could make you slower. To get the best out of yourself, you need to understand your own natural rhythm.
In his latest study Dr Hansen followed a group of subjects for three months and tested their pedalling rates under different conditions.
Previous research had shown that when cycling on the road, riders would naturally choose a higher pedalling rate to go faster – increase their power output – rather than push a harder gear at the same cadence.
In his new study Dr Hansen kept power output levels constant and made the cycling harder by increasing altitude levels; this puts greater stress on the lungs and heart because there’s less oxygen available for the muscles to burn for energy.
He found that the cyclists maintained their pedalling rates even when the going got tough. He also compared these rates with the speed at which they tapped their ﬁngers on a special recording pad and found that, although there was considerable variation between the subjects, the speed at which a given individual tapped their ﬁnger was linked to their pedalling speed, and these rates stayed incredibly stable over the three-month period.
“These results suggest pedalling rates are essentially innate, like other rhythmic movements,” Dr Hansen says. “We, and others, believe networks of neurons in the spinal cord generate natural motor rhythms, personal to individuals, which control a whole series of repetitive responses from pedalling to ﬁnger tapping. This doesn’t mean pedalling rates aren’t inﬂuenced by other factors, but it seems we have a series of default rhythms for tasks like pedalling and ﬁnger tapping that we revert to, other things being equal.”
Breaking out of your own innate rhythm is difﬁcult. If you have a naturally slow pedalling rate, simply jumping up to 100rpm – because it’s what Lance manages – is going to feel very strange. Of course, it might be worth attempting if you could be certain that a higher cadence would bring improvement, and there are a number of studies which, at ﬁrst glance, suggest this may be the case.
In 2004 a team from the University of Madrid got a group of elite cyclists to produce the same power output at different cadences and took various physiological measures to determine the different efﬁciencies. The highest cadence (100rpm) proved far superior.
The general economy level was signiﬁcantly worse at the lowest cadence (60rpm), while mean values of oxygen uptake, heart rate, levels of perceived exertion and lactate decreased as pedalling speed increased. The message, it seemed, was simple: a faster pedalling rate equals greater efﬁciency.
But this is a huge simpliﬁcation according to Dr Hansen. He notes that the cyclists in the Spanish study were asked to cycle at a high intensity for just six minutes.
“For shorter time-trials it is true that a faster cadence is optimal, but the situation changes when exercise becomes less intense," he says. "A much lower pedalling rate is most efﬁcient when cycling for longer periods at a slower pace. This, of course, is still relevant to the majority of road cyclists, who are used to competing in events where they will be riding for many hours rather than just a few minutes.”
Dr Hansen’s experiments have concentrated on the difference between people’s innate pedalling rate and the optimal rate, calculated by the amount of energy expended. He found that at higher intensities – between 80-100 percent of VO2 max – people’s naturally chosen pedalling rate, which tends to be quite high, 80rpm and above, is often extremely close to the optimal rate.
In other words, for short bursts of cycling riders seem to choose an extremely efﬁcient high pedalling rate naturally. Crucially, though, when cycling for long distances at lower intensities, riders largely maintain a relatively high pedalling rate even though a far slower rate is optimal.
“On the longer rides the cyclists’ freely chosen pedalling rates resulted in a five percent higher rate of oxygen uptake on average and a five percent increase in energy expenditure, which is quite substantial when accumulated over the course of several hours of cycling," says Dr Hansen. "I believe there is the possibility for quite large improvements if people adopt a slower rate during low to moderate intensity cycling.”
Convincing cyclists hasn’t been easy. In a 2006 study Dr Hansen asked nine experienced cyclists to ride for 150 minutes on two separate occasions. For one ride they chose their own pedalling rate, but for the other they were asked to ride at the optimal rate, which was generally much slower. Power output was kept constant so for most this meant pushing a much larger gear in the second test.
“They were all complaining, saying they couldn’t ride for so long at the low cadence because it felt so unnatural,” says Dr Hansen.
After half an hour, though, the riders reported the same level of perceived exertion as when cycling at their own freely chosen rate. By the end of the two-and-a-half hours, to their surprise, the cyclists found that their perceived exertion levels were much lower when riding at the optimal rate.
Dr Hansen says the results must be viewed cautiously because it was purely subjective – based on people’s feelings of tiredness rather than actual performance measures.
“We did introduce an objective measure by having the riders complete a ﬁve-minute time trial following the long ride, but although the trend was also for improvement after the optimal pedalling rate trial rather than the freely chosen rate trial, the results were not statistically signiﬁcant,” he says.
What the study does prove, though, is that once you overcome the initial feelings – or perhaps only the idea – of discomfort, it is possible to override your own innate motor rhythm, and it could be beneﬁcial.
“Your innate rhythm is very strong and at high intensities it is difﬁcult to change, which is okay because it appears favourable for cycling economy and performance at these intensities,” says Dr Hansen. “But at lower intensities reductions of about 10-20rpm are possible with practice. Go for small changes at ﬁrst, though, maybe just one gear different.”
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