Energy expenditure during bicycling

Abstract

This study was designed to measure the O2 uptake (VO2) of cyclists while they rode outdoors at speeds from 32 to 40 km/h. Regression analyses of data from 92 trials using the same wheels, tires, and tire pressure with the cyclists riding in their preferred gear and in an aerodynamic position indicated the best equation (r = 0.84) to estimate VO2 in liters per minute VO2 = -4.50 + 0.17 rider speed + 0.052 wind speed + 0.022 rider weight where rider and wind speed are expressed in kilometers per hour and rider weight in kilograms. Following another rider closely, i.e., drafting, at 32 km/h reduced VO2 by 18 +/- 11%; the benefit of drafting a single rider at 37 and 40 km/h was greater (27 +/- 8%) than that at 32 km/h. Drafting one, two, or four riders in a line at 40 km/h resulted in the same reduction in VO2 (27 +/- 7%). Riding at 40 km/h at the back of a group of eight riders reduced VO2 by significantly more (39 +/- 6%) than drafting one, two, or four riders in a line; drafting a vehicle at 40 km/h resulted in the greatest decrease in VO2 (62 +/- 6%). VO2 was also 7 +/- 4% lower when the cyclists were riding an aerodynamic bicycle. An aerodynamic set of wheels with a reduced number of spokes and one set of disk wheels were the only wheels to reduce VO2 significantly while the cyclists were riding a conventional racing bicycle at 40 km/h.(ABSTRACT TRUNCATED AT 250 WORDS)

Tour de France, Giro, Vuelta, and classic European races show a unique progression of road cycling speed in the last 20 years

“…These findings confirm that rHuEPO doping provides a significant physiological advantage consistent with the increase in road cycling performance shown in the present study. Cycling speed and VO2max are correlated in road cycling (McCole, Claney, Conte, Anderson, & Hagberg, 1990), as in all other aerobic sports (track and field, middle-and long-distance running, cross-country skiing, rowing; Seiler, 2006). In a previous study, McCole et al (1990) showed that an increase in speed from 37.5 to 40 km • h -1 may be related to a 7.5% increase in VO2max.…”

“…Cycling speed and VO2max are correlated in road cycling (McCole, Claney, Conte, Anderson, & Hagberg, 1990), as in all other aerobic sports (track and field, middle-and long-distance running, cross-country skiing, rowing; Seiler, 2006). In a previous study, McCole et al (1990) showed that an increase in speed from 37.5 to 40 km • h -1 may be related to a 7.5% increase in VO2max. The expected effect on VO2max has been the major incentive to use EPO in aerobic sports since its discovery.…”

Physiological Response to Cyclocross Racing

“…19,20 Drafting is not as common in cyclocross because the technique is not as beneficial at lower speeds and because it is difficult to perform on varied terrain. 21 The relative speed in cyclocross is lower than speeds found on the road due to the increased rolling resistance of the terrain and the need to navigate through obstacles and/or turns in the course. Because of the difference in drafting, cyclocross is a related but different sport than road or criterium racing, defined much less by teamwork and therefore effort sharing.…”

CFD simulations of the aerodynamic drag of two drafting cyclists

“…While most aerodynamic studies in cycling focused on the aerodynamic drag of a single (isolated) cyclist, several efforts have also been made to assess the effects of "drafting" [2,[15][16][17][18][19][20][21][22]. In drafting, two or more cyclists ride close behind each other to reduce aerodynamic drag.…”

“…From windtunnel runs and coast-down tests, Kyle and Burke [2] observed that air resistance is decreased about 40% for the drafting riders. McCole et al [16] measured the O 2 uptake of cyclists riding outdoors at speeds from 32 to 40 km/h. They found that drafting at 32 km/h reduced VO 2 (i.e.…”