The importance of gender on myokinetic deficits before and after microinjury

Purpose: The purpose of this study was to determine the importance of gende r on myokinetic deficits before and after muscle microinjury. Methods: A re peated measures design assessed selected muscle force production characteri stics in 20 male and 25 female volunteers. Peak force production (PFP) and the peak rate of force production (PRFP) were assessed before and over a 4- 4 period after an induced muscle microinjury. Results: ANOVA revealed stati stically significant mean (+/-SD) differences between men and women for PFP and PRFP (P < 0.0001). Both genders demonstrated significant between-day d ifferences for PFP (P < 0.016), whereas only men demonstrated significant b etween-day differences for PRFP (P < 0.016). Conclusions: Our results revea l that muscle force generating capabilities of physically active men exceed that of women both before and after microinjury. Myokinetic deficits were most pronounced acutely, between 24 and 48 h postinjury, followed by a near complete recovery at day 4 (96 h postinjury). Both genders suffered acute and residual deficits for PFP, whereas only men showed significant acute de ficits for PRFP. We recommend that athletes, both male and female, refrain from strenuous exercise at least 48 h postinjury, or until force-generating capabilities normalize. More research needs to be conducted to substantiat e these findings.