|The Bike Doc
Joined: 08 May 2003
Location: Corpus Christi and Warda, Texas
|Posted: Tue Oct 19, 2004 3:57 pm GMT +0000 Post subject:
HRM calculations of calories burned belong in the same bin that the formula for calculating YOUR maximum heart rate (the 220-age inaccuracy). (See previous thread on Heart rate http://18.104.22.168/phpBB2/viewtopic.php?t=2666 .) The program in the HRM is based on an average rider, of average metabolic activity and average response to exercise. If you were to ride in a controlled environment where rolling resistance of your wheels, wind resistance, incline and speed of riding were all constant, with a correction factor for your body weight then a formula for calculating your calories burned may be a rough estimate of the calories burned. A formula for calculating calories burned is (0.046 x Velocity in MPH x Weight of rider and bike pounds) + (0.066 x Velocity in MPH to the third power [cubed]) + (22 x ft. gained/100) = Calories Burned. Now if you want to plug in all the numbers and come up with an estimate of how many calories burned, please be my guest. The reality is that you do not ride your mountain bike at a constant velocity, on an unchanging incline, with unchanging wind and rolling resistance. Your calories burned will fluctate from moment to moment on your mountain bike ride and an estimate of your calories burned from an average heart rate is a WAG at best. (Wild Ars Guess for the non-engineering inclined.) When I did a medical literature search for validating the caloric expenditure estimations by the HRM, I found no validating studies.
In the college of the real world, ride your bike, eat smart (Let me recommend Nancy Clark's Sports Nutrition Guidebook) and you will gradually find your weight reducing down to what is ideal for your body and metabolism.
Paul K. Nolan, MD
AKA: The Bike Doc