Cycled loads for two and abit months and I didn't lose weight

[Fiona N]

I think BMI is good as an epidemiological tool - looking at whole populations but, if you're not a normal unfit, flabby person (i.e. you're a fit cyclist or other athlete) then the chances of it throwing up some odd things is high.
For example, I'm 1.69m tall and racing weight 25 years ago was around 59kg - I tried never to drop below this as it corresponded to a (properly measured) body fat of only 10% which is getting unhealthily low for a young woman. But the numbers give a BMI of over 20 - so in the middle of the normal weight range. The thing is I'm muscled (or was then) rather like Chris Hoy. Even now, my lean bodyweight (i.e. minus the fat) is still close to 53kg as I do sufficient weight-bearing exercise to maintain it. Keeping a check on body fat percent is probably a better guide than BMI if you tend to a muscular physique.

 

[WimbledonCyclist]

Calculators and books will tell you your calorie consumption when cycling. Trouble is taht that's typically the total energy consumption during exercise, not the incremental energy consumption. So if you burn 100 calories per hour just sitting on your chair, and you get out of your chair & onto your bike for an hour and burn off 400 calories in that time, don't make the mistake of eating 400 calories above your normal food intake.

 

[jimboalee]

Here's a short list of the factors effecting calorific expenditure during cycling.

1/ Tractive Power taking into consideration 'geartrain losses' and 'tyre drag'.

2/ Additional Aerodynamic drag due to wind.

If you are a disciplined cyclist, ignore this next factor.
3/ Mass of idle leg. The energy taken to push the non contributory leg mass upward.
I don't include it.

4/ Windchill on bare flesh.

5/ Windchill on damp clothing.

6/ Energy required to maintain temperature of sweat that is on a wind sheltered part of the body.

7/ Energy required to evaporate sweat off wind sheltered parts of the body.

8/ Hills.

9/ Solar gain.

10/ Energy involved when shouting at motorists.

11/ Energy involved in idle chatting ( noise energy is wasted energy ).


These more-or-less cover it to an acceptable accuracy for my purposes.

 

[jimboalee]

When you've got a realistic number of calories, you then have to assess what proportion of these are taken directly from glycogen stores in your body, and how many are from fat depending in the intensity of your riding.

You then have to assess the capacity of your tanks – short rides won't need feeding.
You will need to devise a 'sliding scale' of distance versus kCals/mile.

You will need to have facility on your spreadsheet to nominate the amount of clothing you are wearing – Long sleeves and trousers, or not? And how thick? This effects the two windchill numbers and contributes a lot to the overall result.

When you've got all the calculations behind a Visual Basic interface, Bob's your uncle.

 

[ASC1951]

I know people will lambast me for saying this but I'm convinced weight loss is so much more about diet than it is about exercise.

That is well established. Exercise won't lose you significant amounts of weight on its own.

 

[jimboalee]

http://www.nutristrategy.com/fitness/cycling.htm

Here's a webpage which gives kCals/hr for some cycling situations.

My nearest equivalent is the 195lb bloke riding 15.9 mph for 885 kCals/hour.

My calcs give 866, and I'm pleased with that.
This is on a flat road through still air at 16 deg C.

If I was to eat 866 calories for a 1 hour ride at 16 mph, I'd put on fat.