Muscle Stiffness and Rate of Torque Development during Sprint Cycling

WATSFORD, MARK1; DITROILO, MASSIMILIANO2,3; FERNÁNDEZ-PEÑA, ENEKO2; D'AMEN, GIANCARLO2; LUCERTINI, FRANCESCO2

Medicine & Science in Sports & Exercise: July 2010 - Volume 42 - Issue 7 - pp 1324-1332
doi: 10.1249/MSS.0b013e3181ce509d
Applied Sciences

Purpose: Crank torque (CT) application and rate of CT development (RCTD) are important considerations in sprint cycling. The stiffness of the musculotendinous unit is related to the isometric rate of torque development (RTD); however, this relationship has yet to be examined in sprint cycling.

Methods: Maximal isometric torque (MIT) and isometric RTD of the quadriceps were assessed in 21 trained male cyclists (28.7 ± 9.5 yr, 1.74 ± 0.08 m, and 67.5 ± 7.2 kg). Unilateral musculoarticular (MA) stiffness of the quadriceps was quantified using an oscillation test. Further, the participants performed a maximal 6-s sprint to assess peak power output (POpeak), peak CT (CTpeak), peak RCTD (RCTDpeak), and the crank angles associated with CTpeak and RCTDpeak. Participants were ranked on MA stiffness properties and were divided into a relatively stiff group (SG) and a relatively compliant group (CG).

Results: The SG displayed a significantly higher MA stiffness than the CG (P < 0.05). Furthermore, the SG reported significantly elevated MIT (27%), RTD (26%), and RCTDpeak (16%) when compared with the CG (P < 0.05), along with trends for increased POpeak (7%) and CTpeak (8%). The angles at CTpeak and RCTDpeak were 7% and 12% lower for the SG, respectively (P < 0.05). MA stiffness was significantly correlated with RCTDpeak, MIT, RTD, and POpeak.

Conclusions: Higher stiffness is related to superior RCTDpeak in trained cyclists during a single sprint. A significant proportion of the variance in RCTDpeak was attributed to MA stiffness (37%), which was of greater magnitude than the relationship between RCTDpeak and MIT. Furthermore, the lower CTpeak angle and RCTDpeak angle may contribute to a more rapid development of CT. Accordingly, MA stiffness seems to be an important consideration for sprint cycling.

1School of Leisure, Sport & Tourism, University of Technology Sydney, AUSTRALIA; 2Istituto di Ricerca sull'Attività Motoria, Università degli Studi di Urbino "Carlo Bo," Urbino, ITALY; and 3School of Physiotherapy and Performance Science, University College Dublin, Dublin, IRELAND

Address for correspondence: Mark Watsford, Ph.D., School of Leisure, Sport& Tourism, University of Technology Sydney, PO Box 222, Lindfield, NSW 2070, Australia; E-mail: mark.watsford@uts.edu.au.

Submitted for publication May 2009.

Accepted for publication December 2009.

©2010The American College of Sports Medicine