Last year, we shot a video: 'How To Pedal Like A Pro', using our combined 40+ years
of experience of both riding and racing, plus the common wisdom that you should pedal in
circles, i.e. dragging your heel through the bottom of the stroke and pulling up etc.
But a lot of people responded in the comments section that this isn't in fact the most efficient
way of pedalling. It is true, there is a wealth of scientific evidence to say that a full
pedal stroke isn't necessarily the most efficient. But I don't necessarily agree with some of
these lab tests, and mainly because my perception is that I do in fact add force to the pedal
stroke somewhere other than just the downstroke.
So we thought "how can we test this out the GCN way?" Thankfully one of the top sports
science centres in the country, here at the University of Bath, have allowed us to do an experiment.
First things first - we do realise that this is not a completely legitimate scientific
experiment. After all, Simon is the only person doing this and according to what he just said,
he's only going to do it once. What we do hope it will prove is once and for all whether
as Si thinks he is more efficient by pedalling around in circles using clipless pedals vs.
just pushing down. Either way, at least we get to put him through some pain. The hypothesis
is that pedalling around in circles is more efficient than simply pushing down and to
test this, he's in a very controlled environment. He's already doing the first of two ten minute
tests. At the moment he's on a 6% incline here on the treadmill riding at 20km/h and
if I just look at the data, that requires around 300 watts and his heart rate at the
moment is about 168 just over a minute through this first test. Once we get to the end of
the ten minutes we're going to analyse various things. The lactate in his blood, we're also
going to analyse some of the things in his breath and also see heart rate etc as well.
Then we're going to repeat the test, but this time we're going to use just flat pedals to
try and eliminate anything which will enable him to pull through at the bottom of the stroke
or even pull up, and then re-analyse all the same metrics at the end of that to come to a conclusion.
OK, Simon's only got 15 seconds left to go now. His heart rate is up to 175, so it's
gradually risen. Almost time to start collecting some data through the breathing analysis and
blood lactate.
Now we've swapped the pedals over for some standard flat ones with some normal mountain
bike pedals which Si is riding on the treadmill now. Exactly the same conditions - we're on
the same incline of 6% and the same speed of 20km/h. Before we give you or even Si some
of the numbers from the last test or during this one, Si, how is it actually feeling at
the moment from your point of view?
Well it's got to be said it feels bloody weird. It does feel harder and it also feels much
less smooth, I'm quite jerky on the treadmill and that's my perception, so I can't wait
to see the numbers.
Right, well you've still got 6 minutes left and so we thought that in that time we'd answer
a burning question that we had from the last time that we came here and used the treadmill.
How is it that a treadmill, where you're effectively not moving anywhere, feels the same as when
you're going up a climb even though you're not gaining any potential energy? Well thankfully
we've got Jonathan here from the University of Bath, who's going to explain.
On the treadmill, we're not actually gaining any elevation, so why does it feel like we're
still climbing?
I think what is a really good point is that we use the treadmill so that it's a really
controlled environment, we can mimic and repeat the speed and the gradient and there's no
changes in environmental conditions, so everything is the same. Obviously the athlete is not
moving forwards or backwards but they are riding against the rolling belt of the treadmill
and given the gradient as well, if they were to stop pedalling they would come off the
back. We know that they are expending energy as they're going through and also as we recorded
the power, we can see what power they are generating.
Thanks very much. I think Si is close to ending his effort now, so let's go and see how he's getting on.
There's now 20 seconds left for Simon, and before we get all of the official numbers,
I can say that I've seen a slight difference here on my own Garmin. 10 seconds to go, Si.
Also important to note that we did allow Si adequate time between the first test and this
one before he went on the treadmill again to make sure that he was completely rested.
2 seconds, 1 second, and stop!
OK Jonathan, let's talk through some hard numbers. Simon's perceived exertion that he
gave you at the end of the 10 minute test - for the first one, the clipless pedals - it
was 13. For the second one it was 15.
The heart rate I was looking at, the average over the last minute was 180 for the flat
pedals and 175 for the clipless. In terms of the blood lactate which you took out at
the end of both tests - how did that come out?
Surprisingly it was actually the same - 3.1 millimoles for both rides so no difference
at all seen there.
So that was similar. In terms of the gas analysis of the breath that you had, how did that come out?
The VO2, which we recorded over the last 3 minutes actually came out at slightly different
values, so 51 ml per kilo per minute for the flat pedals and 53 ml per kilo per minute.
Wow, so he was consuming more oxygen with the clipless pedals than he was with the flat pedals?
Yes. The clipped pedals were actually eliciting a higher oxygen consumption.
So perhaps the opposite to what we were expecting, that's interesting. OK let's go and have a
word with Si now that he's recovered slightly to see how he feels about those results.
Simon, Jonathan's just given us the results and surprisingly the flat pedals appear in
this single test to be slightly more efficient than your clipless pedals, so what do you
make of that?
Yeah, I'm scratching my head a little bit to be honest with you Dan. I am surprised,
but I've been thinking about it a little bit and the main feeling is that when I was pedalling
with the flat pedals it felt like my shoe was almost always about to come off the pedal.
But then the fact that it was almost coming off but not quite means that I suppose my
natural pedalling style is one where I don't actually pull up, which I suppose I never
really knew. But then, if it's not adding anything then presumably it should be as efficient,
if not more efficient just using flat pedals. But I'm not going to throw away my clipless
pedals just yet because for a start I can't bunny hop without them! And also, this is
a steady state ride. As you well know, even in a race situation, the amount of times where
you have to accelerate really hard, I know full well that I do pull up when I'm generating
the most peak power that I can and therefore in a normal environment clipless pedals are
still going to be the ones that win out.
I guess that's the thing, isn't it? The laboratory here does take all external factors out, but
when you're racing or training on the road, you have all of those external factors. Anyway,
stay tuned to GCN because we're going to be coming back here to the University of Bath
to do more experiments with myself and Si on this treadmill which should help to answer
a lot of your burning questions.