How are the Challenge statistics calculated?
CO2Carbon emissions can be estimated from the distance travelled using average emission factors for modes of transport.
The statistic for the amount of CO2 saved by cycling on this website relates to cycle trips that have been logged for transport purposes only. The statistic relates to the total amount of CO2 released by an average car, illustrating an estimation of the amount of CO2 saved by cycling instead of driving. It is calculated as follows:
Total units travelled x kg CO2 per unit = total kg CO2
This calculation is the total distance of trips logged for transport purposes times the amount of CO2 released by an average car, which equals the total kilograms of CO2 per kilometre.
For the purposes of this Challenge, Defra’s carbon conversion factor for an average car (fuel unknown) was used. This is 0.20282kg of CO2 per kilometre as provided in ‘Guidelines to Defra’s Greenhouse Gas Conversion Factors for Company Reporting’, June 2008. For a copy of this report please see here.
Please note that the above calculation acts as a guide to carbon emissions only and is used across our global Challenge websites. For Australia, the Australia Bureau of Statistics and Department of Climate Change factors can be taken into account for a more accurate measurement.
Carbon emission factors/km = 0.111 x 2.56 = 0.2843
This is 40% higher than Defra’s data and so carbon emmissions in Australia can be reported as 40% more than stated on this website. This is due to the fact that the average Australian passenger petrol vehicle fuel efficiency is 0.111 L/km (ABS 2007) and emissions are 2.56 kgCO2e/L (DCC National Greenhouse Accounts factors (June 2009), gasoline (petrol), full scope 1 & 3 emissions). Reference: ‘Survey of Motor Vehicle Use, Australia, 12 months ended 31 October 2007, Australian Bureau of Statistics 2008, 9208.0. For a copy of this report see here. (Information courtesy of Carbon Planet.)
FatCycling burns body fat and so cycling regularly can reduce our body fat percentage. One kilogram of body fat is approximately equal to 7,700 calories. The statistic on this website for the total amount of fat burnt by participants relates to the total amount of energy expended for all cycle trips logged divided by the amount of calories per kilogram of fat.
Total energy expended = total kilograms of fat expended
CaloriesA calorie is a measure of energy expenditure. The actual calories burned by a cyclist vary based on weight, age, body mass index, terrain, speed, wind etc. There are too many variables to accurately calculate calorie usage and so the statistic on this website is an approximation.
Dr. Edward Coyle of The University of Texas in Austin did a study to determine the average values of oxygen consumption by cyclists at different speeds. This information (based on an average-size adult of approximately 70kg) has been used to create a conversion factor table to estimate the approximate caloric equivalence between running and cycling:
A moderate cycling speed of 25 kilometres per hour has been assumed for our calculation of calorie expenditure with 18 calories burned per kilometre.
Distance (kilometres) x calories/km = total calories Distance (kilometres) x 18 = total calories
If you would like to gain a more accurate calorie calculation that takes into account more variables, please see the following calorie calculator.
EnergyEnergy can be measured in kilojoules and calories. One calorie has the same energy value as 4.184 kilojoules.
The total energy burnt by participants cycling has been measured using the calorie calculation as above and converting this figure into kilojoules by multiplying the value by 4.184.