Is the cross-over effect of a unilateral high-intensity leg extension influenced by the sex of the participants?

Abstract

BackgroundWhile performing a unilateral muscle contraction, electrical muscle activity also arises in the contralateral homologous muscle, muscle group, or limb. When the muscle contraction induces muscle fatigue, females show not only a greater resistance than males but also a reduced contralateral muscle activation. The study aimed at investigating whether, during a high-intensity 30-s unilateral maximal effort isometric leg extension exercise, the contralateral non-exercising limb (NEL) knee extensor muscle activation would differ between females and males.MethodsTwenty participants, 11 females (23.80 ± 2.15 years old) and 9 males (26.50 ± 2.45 years old), performed a unilateral 30-s exercise while surface electromyography (sEMG) was measured from the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) on both limbs. The maximal voluntary contraction (MVC) was measured for both the exercising limb (EL) and the NEL before (MVC PRE) and after (MVC POST) the 30-s exercise to assess muscle fatigue.ResultsWhile both females and males exhibited muscle fatigue in the EL (p = 0.015), females exhibited a lower MVC reduction than males (p = 0.042), suggesting that females were less fatigued than males. Although no muscle fatigue, i.e., no MVC force reduction was found in the NEL for either group before and after the 30-s exercise, the muscle activity of the VL was found to be of greater magnitude during the MVC POST only for females (p = 0.047) while it remained unchanged for males. During the 30-s exercise, the force output of the EL decreased only for males (p = 0.029) while females showed a preservation of the force output (p > 0.05). The sEMG activity of the NEL during the 30-s unilateral exercise increased for both groups in all measured muscles (all p-values < 0.03).ConclusionsLikely, different underlying muscle fatigue mechanisms occurred in the EL between females and males. Yet, our findings suggest that the cross-over effect to the NEL during the 30-s exercise occurred in a similar fashion in both groups. The current study suggests that the contralateral muscle activation seen with a unilateral exercise is independent of the sex of individuals. Therefore, unilateral training or rehabilitation-based protocols would similarly impact females and males.

Non-local muscle fatigue effects on muscle strength, power, and endurance in healthy individuals: A systematic review and meta-analysis

“…Martin and Rattey [8] and Ye et al, [50] were two of only three studies to directly compare sex-related NLMF effects, finding greater NLMF with males vs. females. Doix et al [80] contrastingly discovered that males experienced greater fatigue in the exercised leg but there was no significant NLMF with either sex, although vastus lateralis EMG activity demonstrated a greater magnitude deficit during the post-test with females. Females tend to exhibit greater muscle endurance [111] and indeed experience less local muscular fatigue [112], which has been attributed to lower absolute muscle forces with the same relative work, contributing to a lower muscle oxygen demand and vasculature compression [113] In contrast, males are more reliant on glycolytic pathways and present a greater neuromuscular activation impairment after fatigue [111,113].…”

“…Please consider donating at www.storkinesiology.org/annual 15 drive. Further questioning the impact of centrally mediated neural mechanisms, studies that have examined electromyographic activity (EMG) of the non-exercised muscle are conflicting in whether there appears to be evidence of neural inhibition [8,10,15,[79][80][81]. While there is evidence suggestive of reduced cerebral oxygenation possibly impacting NLMF [82,83], evidence from studies of transcranial magnetic stimulation (TMS) regarding specific levels neural influence (i.e.…”

Unilateral Quadriceps Fatigue Induces Greater Impairments of Ipsilateral versus Contralateral Elbow Flexors and Plantar Flexors Performance in Physically Active Young Adults

“…A relatively recent field of fatigue research has explored how localized fatigue can impair force output in muscles that have not been directly exercised (Halperin et al, 2014a;2014b;Kennedy et al, 2013). This global effect of fatigue has been classified as crossover (Doix et al, 2018;Martin and Rattey, 2007;Rattey et al, 2006) or nonlocal muscle fatigue (NLMF) (Halperin et al, 2015). NLMF refers to deficits of maximal force output in any contralateral or ipsilateral, homologous or heterologous, non-exercised muscles (Halperin et al, 2015, Miller et al, 2019, Ye et al, 2018, whereas crossover fatigue is a subgroup of NLMF and specifically describes the impairment of a contralateral, homologous, non-exercised muscle (Doix et al, 2018;Halperin et al, 2015;Martin and Rattey, 2007).…”

“…This global effect of fatigue has been classified as crossover (Doix et al, 2018;Martin and Rattey, 2007;Rattey et al, 2006) or nonlocal muscle fatigue (NLMF) (Halperin et al, 2015). NLMF refers to deficits of maximal force output in any contralateral or ipsilateral, homologous or heterologous, non-exercised muscles (Halperin et al, 2015, Miller et al, 2019, Ye et al, 2018, whereas crossover fatigue is a subgroup of NLMF and specifically describes the impairment of a contralateral, homologous, non-exercised muscle (Doix et al, 2018;Halperin et al, 2015;Martin and Rattey, 2007). Contrary to these concepts however, numerous studies failed to show NLMF effects (Aboodarda et al, 2019;Andrews et al, 2016;Doix et al, 2018;Grabiner and Owings, 1999;Hamilton and Behm, 2017;Kennedy et al, 2015;Morgan et al, 2019;Prieske et al, 2017).…”

Interactions between perceptions of fatigue, effort, and affect decrease knee extensor endurance performance following upper body motor activity, independent of changes in neuromuscular function

“…Finally, though previous assertions indicate a separation between perceptual responses to exercise and neuromuscular function following prior, remote exercise, the effect of prior exercise on the neuromuscular function in non‐active , remote muscles remains ambiguous (see Halperin, Chapman, & Behm, 2015). Evidence of impaired maximal force production in non‐active muscle groups following remote exercise is currently equivocal (Doix et al., 2018; Doix, Lefèvre, & Colson, 2013; Rattey, Martin, Kay, Cannon, & Marino, 2006; Šambaher, Aboodarda, & Behm, 2016; Sidhu et al., 2014; Triscott et al., 2008). Moreover, transcranial magnetic stimulation (TMS) studies have reported both excitatory and inhibitory effects on the excitability of the corticospinal tract of remote muscle groups (Aboodarda, Šambaher, Millet, & Behm, 2017; Šambaher et al., 2016).…”