title: Level ground and uphill cycling efficiency in seated and standing positions.
abstract: OBJECTIVE
  This study was designed to examine the effects of cycling position (seated or standing) during level-ground and uphill cycling on gross external efficiency (GE) and economy (EC).
  
  
  METHODS
  Eight well-trained cyclists performed in a randomized order five trials of 6-min duration at 75% of peak power output either on a velodrome or during the ascent of a hill in seated or standing position. GE and EC were calculated by using the mechanical power output that was measured by crankset (SRM) and energy consumption by a portable gas analyzer (Cosmed K4b(2)). In addition, each subject performed three 30-s maximal sprints on a laboratory-based cycle ergometer or in the field either in seated or standing position.
  
  
  RESULTS
  GE and EC were, respectively, 22.4 +/- 1.5% (CV = 5.6%) and 4.69 +/- 0.33 kJ x L(-1) (CV = 5.7%) and were not different between level seated, uphill seated, or uphill standing conditions. Heart rate was significantly ( < 0.05) higher in standing position. In the uphill cycling trials, minute ventilation was higher ( < 0.05) in standing than in seated position. The average 30-s power output was higher ( < 0.01) in standing (803 +/- 103 W) than in seated position (635 +/- 123 W) or on the stationary ergometer (603 +/- 81 W).
  
  
  CONCLUSIONS
  Gradient or body position appears to have a negligible effect on external efficiency in field-based high-intensity cycling exercise. Greater short-term power can be produced in standing position, presumably due to a greater force developed per revolution. However, the technical features of the standing position may be one of the most determining factors affecting the metabolic responses.
authors.affiliation: UPRES-EA 2991 Sport, Performance, Santé, Faculté des Sciences du Sport, Montpellier, France. g.millet@staps.univ-montp1.fr
authors.forename: Grégoire P
authors.initials: GP
authors.lastname: Millet
authors.forename: Cyrille
authors.initials: C
authors.lastname: Tronche
authors.forename: Nicolas
authors.initials: N
authors.lastname: Fuster
authors.forename: Robin
authors.initials: R
authors.lastname: Candau
mesh_terms: D000293:Adolescent; D000328:Adult; D001642:Bicycling / Q000502:physiology*; D016552:Ergometry; D005080:Exercise Test; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D011659:Pulmonary Gas Exchange