Effects of body position on anaerobic and aerobic power in cyclists and triathletes during cycling.

摘要

Proper body position on the bike is very important for both triathletes and cyclists. The following three studies examined the effects of body position on performance. The first study examined aerobic power production to determine if it was specific to training position between an aero (in aero bars) and upright (hands on the brake hoods) position. Cyclists, who never train in aero bars, and triathletes, who only train on aero bars, participated in these studies. In study one both groups completed two 30-minute rides at 70% of VO2max, one trial upright and the other aero. When examining VO 2, it was found that there was an increased metabolic cost to riding in aero bars in cyclists (43 +/- 5.5 aero and 41 +/- 5.8 ml/kg/min upright) and that there was no difference in economy between the two positions in triathletes (39 +/- 5.4 aero and 38 +/- 5.3 ml/kg/min upright). The second study compared anaerobic power production between the two groups using a 30s Wingate test. One trial was conducted upright and the other in the aero position. Peak power and mean power were used to determine anaerobic power production. Cyclists performed better upright (768W +/- 74.7 W upright and 706W +/- 69.4W aero) and triathletes performed better in an aero position (697W +/- 75.9W upright and 750W +/- 111.53W aero). It is recommended from the first two studies that cyclists and triathletes train in the position that they race in. The third study examined two different methods for adjusting saddle height and compared them against two standards. The two standards used were: (1) determining saddle height using Hamley method (109% of inseam) which is used for optimal economy, and (2) using a goniometer to obtain a knee angle of 25--35°, for injury prevention. The two methods compared against these standards were: (1) the LeMond method, and (2) the heel-toe method. It was found that the Hamley method or the LeMond method produced similar results and could be used interchangeably for economy. For injury prevention it is recommended that a goniometer be used to ensure a 25--35° knee angle.