Acute effects of small changes in crank length on gross efficiency and pedalling technique during submaximal cycling

• DOI: 10.28985/jsc.v3i2.98
• Publication Date: 2014-07-12
• Authors: Ventura Ferrer-Roca; Víctor Rivero-Palomo; Ana Ogueta‐Alday; JA Rodríguez-Mar...; J García-Là pez
• Keywords: Crank; Cycling; Cadence; Respiratory exchange ratio

Background: To the best of our knowledge, only four experimental studies analysed influence crank length in efficiency energy consumption. No significant differences were found on metabolic cost while pedalling with lengths between 145 and 200 mm. None these took into account changes technique (kinetic kinematic profile), which might affect both consumption muscular activity profile lower limb (Astrand, 1953: Arbeitsphysiologie, 15, 23-32; Klimt & Voigt, 1974: European Journal Applied Physiology, 33, 315-326; Morris Londeree, 1997: Canadian 22, 429-438; McDaniel et al, 2002: 93, 823-828). Purpose: The main purpose this study was to assess acute effects small assumable by competitive cyclists (±5 mm) during submaximal cycling.Methods: Twelve well-trained road a minimum two years competing cycling training more than 3000 km participated study. They performed randomized order three sets (150, 250W) at constant cadence (90 rpm) using commonly used (preferred, +5 mm -5 mm). Simultaneous physiological (oxygen uptake, respiratory exchange ratio, heart rate gross efficiency) biomechanical analyses (sagittal hip, knee ankle angles obtained 2D high-speed video; torque exerted left right cranks independently every 2Âo complete revolution). Two-way ANOVA repeated measures analyse effect power output variables. Results: Non-significant oxygen RER, (p>0.05). There (p<0.001) maximum (longest increased it 1.0-2.3 N•m), 1.0-2.2 N•m) MFE decreased 1 0.9-1.9%). Longest also (p<0.05) flexion range motion hip (0.9-2.5°) (1.3-3.4°), whereas joint not affected. i‚´ found. Discussion: outcome that intensity did produce variables (kinetics kinematics) produced. A longer due greater upstroke. Moreover, Conclusions: In conclusion, kinetic enough alter consumption, although future should investigate their long term muscle coordinative pattern distance events overuse injuries.