AUTHOR=Davies Robert W. , Carson Brian P. , Jakeman Philip M. 

TITLE=Sex Differences in the Temporal Recovery of Neuromuscular Function Following Resistance Training in Resistance Trained Men and Women 18 to 35 Years

JOURNAL=Frontiers in Physiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2018.01480

DOI=10.3389/fphys.2018.01480

ISSN=1664-042X

ABSTRACT=<p>To investigate sex differences in the temporal recovery of neuromuscular function following resistance training (RT), eleven men and eight women 18–35 years completed a single RT bout (barbell back-squats, 80 % 1RM, 5 sets × 5 reps, 25 % duty cycle, then 1 set × max reps). Measures of muscle function (isometric, concentric, eccentric knee extensor strength, and countermovement jump (CMJ) height), serum creatine kinase activity (CK) and lower-body muscle pain were assessed before RT (0 h), +4 h, +24 h, +48 h, and +72 h post-RT. Data are mean % change from PRE (SD) and effect size (ω<sup>2</sup>, d). Men and women had similar RT-experience (men, 2.1 (0.8) years vs. women 2.4 (1.0) years, <italic>P</italic> = 0.746, and <italic>d</italic> = 0.3) and 1RM strength per kg lean mass (men, 1.9 (0.2) kg⋅kg<sup>-1</sup> vs. women, 1.8 (0.3) kg⋅kg<sup>-1</sup>, <italic>P</italic> = 0.303, and <italic>d</italic> = 0.3). A 36 (12)% increase in lower-body muscle pain was reported following RT (<italic>P</italic> &lt; 0.05, <italic>d</italic> &gt; 0.9). There was an absence of any overt change in CK [+24 h, 74 (41) IU⋅L<sup>-1</sup>; pooled mean (SD)]. Decrements in knee extensor strength and CMJ height were observed +4 to +72 h for both men and women (<italic>P</italic> &lt; 0.05, ω<sup>2</sup> = 0.19–0.69). Sex differences were apparent for CMJ height (+24 h men, -10 (6)% vs. women, -20 (11)%, <italic>P</italic> &lt; 0.001, and <italic>d</italic> = 1.8) and isokinetic concentric strength (+24 h men, -10 (13)% vs. women -25 (14)%, <italic>P</italic> = 0.006, and <italic>d</italic> = 1.8), with a more pronounced loss and prolonged recovery in women compared to men (e.g., CMJ + 72 h men, -3 (6)% vs. women, -13 (12)%, <italic>P</italic> = 0.051, and <italic>d</italic> = 1.1). We conclude that the different temporal recovery patterns between men and women are not explicable by differences in muscle strength, RT performance, experience, muscle damage or fatigability.</p>