Quadriceps low‐frequency fatigue and muscle pain are contraction‐type‐dependent

Eccentric contractions are thought to induce greater low‐frequency fatigue (LFF) and delayed‐onset muscle soreness (DOMS) than concentric contractions. In this study we induced a similar amount of eccentric quadriceps muscle fatigue during either a concentric or eccentric fatigue task to compare LFF and DOMS. Subjects (n = 22) performed concentric or eccentric fatigue tasks using 75% of the pre‐fatigue maximal voluntary contraction (MVC) torque, and both tasks ended when the MVC eccentric torque decreased by 25% pre‐fatigue. When subjects reached the failure criterion during the eccentric and concentric tasks, the concentric MVC was 78 ± 9.8% and 64 ± 8.4% of initial, respectively. LFF was greater after the concentric than the eccentric protocols (22 ± 12.4% and 15 ± 7.6% increase, respectively; P < 0.01). DOMS was over 100% greater for the eccentric protocol. These results indicate that DOMS is not dependent on the events that contribute to LFF. Muscle Nerve, 2010