So I started using SportTracks today (see GPS vs Cycle Computer thread), and there’s a setting for calculating burnt calories dependant on things like gradient, speed etc. However the calculation for calories based on the bike formula is way off (I rode for a couple of hours today, hardcore trails, and it says I burnt 443 calories, but I reckon I burnt several thousand calories at least).

So my question is, has anyone ever tried to work out a calorie calculation formula for unicyclists? The closest analogy IMHO would be a single-speed bike, but I can’t find anything on google about calculating calories based on gear ratio, only things like air resistance and transmission efficiency (not very useful at <10mph and with direct drive). Plus Unicyclists expend energy to balance, and cannot coast, increasing the expendature again. I did do a forum search for ‘Calorie’ and ‘Energy’ and found George Winters’ Page on Unicycle Energy expendature. I’m not mathematical enough to formulate something like this, and not confident enough with energy calculations to try and calculate the work exerted in normal conditions, but I think that the calories burnt would depend on:

Rider+Unicycle combined weight, Cadence, Gradient, Distance travelled, Unicyclist Skill (a beginner expends more energy on balance), and wheel size (speed against air resistance). Possibly more things too (wheel resistance being one, a fat muni tyre wastes more energy than a high pressure 700c big apple).

NB: I’m talking more about distance/trail riding here, drops and hops for hardcore muni and trials will of course expend stupid amounts of energy, but won’t allow for a simple ‘Rider of this mass, on this unicyle, for this long’ calculation.

I’ve done the calculations for various bicycle gears going uphill, but I seem to have misplaced the paper.

One thing you could try is to keep track of how many calories you consume to keep your weight constant after you unicycle for a specified time compared to when you don’t unicycle. Then you can get an estimate of how much your bicycle computer deviates from reality, and, assuming a direct relation between calories burnt on a unicycle vs. bicycle, you can then just multiply the amount on your computer by a certain factor to arrive at a better estimate.

My personal theory is that an average cheap bike calorie counter is more accurate on a unicycle than a bike, BECAUSE it doesn’t factor in things like coasting.
443 calories is a lot. That’s about 13 or 14 miles of biking.

Re: Unicycling Calorie Calculation Formula? (For GILD’s title filter: “Does this exist?”)

On Sat, 11 Feb 2006 13:31:29 -0600, Loosemoose wrote:

>Anyone ever looked into this?

Not yet. I have some vague plan (low on my To Do list) to look at my
data and come up with something like this. Over the last few years, I
have been tracking most of my rides with GPS, and I have kept accurate
notes of energy intake and weight. So the data (for myself) should be
there, in a way. (Not much non-horizontal riding here, though.)

I have never even tried to do some research with Google yet, that
should be telling about how imminent my ‘vague plan’ is. I’m
interested in whatever you come up with.

I think there’s a massive issue here with skill levels. Good riders will use so much less energy to go the same distance at a particular speed.

I think most people over-estimate how many calories they’re using up doing exercise in general, so it’s hard to rely on personal experience for this one. Having said that, I know for 10 hours of non-stop distance riding, I took on about 3000 calories of food + energy drinks and felt okay, not like I was low on anything afterwards. That was riding absolutely full on, with 45 minutes of breaks in total. So I’d guess that my distance riding uses at least 300 calories an hour maybe a bit more.

One thing I can say is that I use up way more calories per hour doing fast distance bicycling than unicycling. Riding a bike at 18 or 19 mph proper average (including stops) is way more tiring than riding a unicycle at 10-12mph average. My commute takes more energy on a bike, although less time. Once you get efficient at unicycling, the limiting factor isn’t so much fitness as spinning ability, even on a coker with 110s.

I think muni does take more energy though, I remember I once did a 10 hour muni ride on my own, riding as fast as I could most of the time over somewhat technical and hilly terrain, after that I needed to be fed lots of food and pretty much fell asleep for a day. It’s hard to take on enough energy for that much technical riding, especially as I wasn’t using energy drink that ride.

Energy expenditure is a complex issue - Your body uses a large amount of energy at rest and this enables it to be a very efficient machine, when it comes to added work. There’s not as much difference between lying down and running flat out as you might think. When unicycling (even hardcore trials) you might be burning energy at as much as 5 times the rate you would at rest, but if you’re only doing it for a couple of hours a day then that’s like an extra 8 hours of rest crammed in to your day, so your total energy expenditure is “only” increased by 33%. (32 divided by 24)

Frequent exercise though increases your resting requirement for energy, and it’s mainly this increase that causes people to loose weight from exercising, because this increase applies throughout the night and day.

I’m very sceptical of these calorie estimating gadgets. Mainly because of the physiology above but also because it would be in the manufacturer’s interests to for them to over-estimate as this will fuel the exercise industry.

I agree! Except that when switching the Garmin forerunner 201 from cycling to running it will only report speeds in minutes/mile. I prefer miles/hour and thus I’m stuck with calorie computations based on cycling.

Maybe I could grossly overstate my weight in the device and it would more accurately report calories burned?

Re: Unicycling Calorie Calculation Formula? (For GILD’s title filter: “Does this exist?”)

On Sun, 12 Feb 2006 13:30:43 -0600, rupert wrote:

>Just remembered - technically calorie with a lower-case C is one
>thousandth the energy of a Calorie (kilocalorie) with a capital C.
>
>In practice, certainly in the context of nutrition, whenever someone
>says calorie or writes it without a capital, they mean a kilocalorie.

That is one issue with the calorie/Calorie. The other one is that it
is an obsolete unit, for which there are several definitions that work
out slightly different.

The only proper unit for energy is the Joule. Or for food energy
content, the kJ (kiloJoule) is more convenient. The Joule has a single
non-ambiguous SI definition (1Joule = 1 Watt second, while 1 Watt = 1
Newton meter).

I was unaware of the ambiguity here. I thought that a calorie was the energy required to raise one gram of water one degree centigrade. Is the ambiguity in the variation of the thermal capacity of water at different temperatures or perhaps some other non-linearities?

You’re spot on - the range that the temperature increase was over wasn’t defined, so people used different ones, which led to slightly different units. The differences are too small to be of any concern when talking about nutrition, but Klaas is right that for any other purpose we should really use the joule. The dietetics on my course has been taught in both, but I found it more convenient to remember the nutrition information in Calories.

Re: Unicycling Calorie Calculation Formula? (For GILD’s title filter: “Does this exist?”)

On Mon, 13 Feb 2006 01:37:36 -0600, rupert wrote:

>The differences are too small to be of any concern
>when talking about nutrition, but Klaas is right that for any other
>purpose we should really use the joule.

I meant to say that “we” should do away with the calorie altogether,
and so also for nutrition use the J (or kJ for that matter)
exclusively. SI rules.