CYCLING PERFORMANCE TIPS

TOTAL ENERGY REQUIREMENTS OF CYCLING
horizontal PLUS vertical work
(expressed as Calorie replacement requirements)

*****PLEASE NOTE that the variables may be labeled differently on this page*****

I. Level road (Eh=energy replacement required-horizontal component)

This is the formula to calculate the number of Calories needed (to be eaten) to replace those expended riding on level terrain.


Where:

Assumptions:

*Speed is your AIR speed (ie the resistance you are pedalling against is the resistance of the air to your body and bike as you ride) and is not your GROUND speed off your computer. So if there is a head wind, add that speed to your ground speed to determine the velocity for this formula. And if it is a tail wind, subtract it from your ground speed. If you think about it, this makes sense - it is always easier to ride with a tail wind. This formula quantitates how much easier.

**(Unfortunately, this formula is for an "ideal" rider of 75 kg. I could not find the original derivation and so cannot give you the exact changes if your weight is more or less than 75 kg. But biking is NOT an exact science, and this formula will at least get you into the right ballpark - ed)

Definitions and conversion factors:



II. Vertical Distance (Ev = energy replacement required-vertical component)

When the terrain is not level, and there is vertical gain, this formula calculates the number of Calories that would need to be eaten to replace those expended for the vertical gain only.

Where:

Definitions and conversion factors:


III. TOTAL ENERGY REQUIREMENTS - UNEVEN TERRAIN

By combining the calculations for the horizontal component of energy expenditure and the component from vertical gain, the TOTAL Caloric replacement needs for your ride can be determined.

Etotal = Eh + Ev

And finally, don't forget the approximately 50 Cal/hour for basal metabolism.



AN EXAMPLE

A 165 pound cyclist (75 kg) rides a 10 mile hilly route at an average speed of 15 mph (6.7 meter/sec). During the ride, he climbs 1500 feet (457 meters). His bicycle weighs 22 pounds (10 kg). How many Calories will he need to eat to replace the energy expended??


REFERENCES

BICYCLING FUEL by Richard Rafoth Bicycle Books - San Francisco Calif 1993

BICYCLING SCIENCE by Frank Rowland Whitt et al The MIT Press Cambridge, 1985


Questions on content or suggestions to improve this page are appreciated.

Cycling Performance Tips
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