What is Body Mass Index (BMI) and What is its Practical Application in Terms of Endurance Performance?
By William Misner, Ph.D.
The importance of one's body mass index (BMI) lies in its curvilinear relationship to mortality rates. As a BMI increases, so also do the risks of several life-ending degenerative diseases. The lowest "risk to health" range of BMI is found between 20-25. A desirable BMI for men is 21.9-22.4. A desirable BMI for women 21.3-22.1. A BMI below 20 is the same health risk as seen in those between 30-35. How does one figure out BMI?
HOW TO FIGURE YOUR OWN BMI
The equation for BMI is weight in kilograms divided by height in meters squared (wt/ht2=BMI). EXAMPLE: One(1) pound equals 0.45 kilograms---150 lbs. X 0.45=67.5 kg. At 5'10" or 70 inches tall, 1"=.0254 meters, or 1.778 meters tall. Next, divide your weight of 67.5 kg. by 1.778 squared(3.16)=21.36 BMI! Now that you have calculated your body mass index, let us take a look at the BMI's of several of the great cyclists who rode the 1997 Tour De France to see how you compare. BMI on a climbing course is one factor of many in total performance variables. Sprinters tend to have higher body masses while true climbers tend to have lower BMI, irregardless of height. Height ranges for those on the Tour in 1997 ranged from 1.61 to 1.94 meters tall. The average height was 1.79, the average weight was 68.75, and the average BMI was 21.47.
Here are the BMI's of a few standout well-known Tour De France 1997 riders.
With whom do you compare?
|TOUR DE FRANCE RIDER||height (m.)||weight (kg)||BMI|
|Average for 1997 TDF||1.79||68.75||21.4701|
While the above select list is inconclusive as to which BMI is optimal for intense & long-duration cycling events, it does present the ranges at which appears the athlete may perform best.
For further research, Ian Rogers posted the sportscience list with these helpful references on BMI (see below).
- Physiological characteristics and their relationship to performance in off-road cycling. Sewall KA, Fernhall B. Sports Medicine, Training and Rehabilitation. V.6 89-95. 1995
- Physiological profiles of elite off-road and road cyclists. Randall Wl, Zawadski KM et al. Medicine and Science in Sports and Exercise. V. 29 (8) pp. 1090-1094. 1997
- Effects of body mass on exercise efficiency and O2 during steady state cycling. Berry MJ, Storsteen AJ, Woodward CM. Medicine and Science in Sport and Exercise V.25 (9) pp.1031-1037. 1993
- The influence of body mass in endurance cycling. Swain DP. Medicine and Science in Sport and Exercise V.26 (1) pp. 58-63. 1994
- Physiological and biomechanical factors associated with elite endurance cycling performance.Coyle EF, Feltner ME et al. Medicine and Science in Sport and Exercise V.23 (1) pp. 93-107. 1991
- The effects of Mountain Bike Suspension Systems on Energy Expenditure, Physical Exertion,and Time Trial Performance During Mountain Bicycling. Seifert JG, Luetkemeier MK et al.International Journal of Sports Medicine V.18 (3) pp. 197-200. 1997