Pioske, JS, Arnett, JE, Roberts, TD, Ortega, DG, Schmidt, RJ, and Housh, TJ. The effects of fatigue-induced velocity loss on performance and neuromuscular responses during leg extension repetitions performed with maximal intended velocity. J Strength Cond Res XX(X): 000–000, 2026—Strength and power adaptations are dependent on the magnitude of the physiological stimulus during resistance exercise. Therefore, the present study examined the changes in velocity, force, power, and acute neuromuscular responses of the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) during maximal intended velocity (MIV) leg extension repetitions at velocity losses (V _Loss ) of 5, 15, and 25%. Twelve men (age: 21.67 ± 2.00 years) performed MIV unilateral leg extensions to failure at 40% 1RM with their nondominant leg. Mean and peak values for velocity, force, and power were recorded with a linear transducer, whereas surface electromyographic amplitude (EMG AMP) and mean power frequency (EMG MPF) values were assessed from the RF, VL, and VM. Repeated measures ANOVAs with Bonferroni-corrected post-hoc comparisons ( α = 0.0083) revealed that mean and peak values for velocity and power (−5.9 to −42.3%), and peak values for force (−5.8 to −20.2%) decreased at all V _Loss repetitions, whereas mean force decreased at 15% (−0.6%) and 25%V _Loss (−0.9%) repetitions. EMG MPF decreased for the RF at all V _Loss repetitions, whereas the VM and VL decreased at 15% and 25%V _Loss , and 25%V _Loss , respectively. EMG AMP increased for all 3 muscles at 15% and 25%V _Loss . These findings suggested muscle-specific differences in the development of peripheral fatigue and possible intermuscular motor unit synchronization to maintain the MIV effort. It is recommended to use peak instead of mean V _Loss to monitor the fatigue-induced decreases in force and power because peak values more closely tracked the fatigue-induced decreases in EMG MPF during MIV leg extensions.

Ortega, DG, Smith, RW, Arnett, JE, Neltner, TJ, Roberts, TD, Pioske, JS, Schmidt, RJ, and Housh, TJ. Wavelet-based electromyographic and mechanomyographic intensity responses to fatiguing tasks anchored to a rating of perceived exertion versus torque. J Strength Cond Res XX(X): 000–000, 2026—This study used wavelet analyses to examine the effects of anchor scheme on electromyographic (EMG) and mechanomyographic (MMG) intensity. Twelve men (age = 20.9 ± 2.2 years) performed maximal voluntary isometric contractions (MVICs) before and after sustained, isometric forearm flexion tasks anchored to a rating of perceived exertion (RPE) of 4 (RPE4 _FT ) and the torque (TRQ4 _FT ) that corresponded to an RPE of 4. Wavelet analyses were used to decompose the EMG and MMG signals recorded from the biceps brachii during the MVICs onto sets of 11 nonlinearly scaled Cauchy wavelets. Repeated measures analyses of variance were used to analyze the EMG and MMG intensity data, with significance set at p ≤ 0.05. After the RPE4 _FT , EMG intensity decreased ( p = 0.004 to 0.047) at wavelet bands 5 and 8–11. After the TRQ4 _FT , EMG intensity increased ( p = 0.009) at wavelet band 1 and decreased ( p < 0.001 to p = 0.047) at wavelet bands 5–11. The MMG intensity distribution across the 11 wavelet bands did not differ ( p > 0.05) between the sustained tasks and remained unchanged from pretest to post-test MVIC. Taken together, the EMG and MMG intensity responses suggested that, despite the presence of peripheral fatigue, which affected the TRQ4 _FT to a greater extent than the RPE4 _FT , motor units were maximally recruited with no change in their firing rates from pretest to post-test MVIC. Thus, the application of wavelet-based spectral analyses offers a sensitive approach for detecting subtle changes in muscle function, which has important implications for advancing diagnostic precision and developing targeted interventions in sports performance, rehabilitation, and clinical assessments of neuromuscular health.

This study: (1) Determined the time course of early-phase adaptations in average peak torque (APT), the rate of velocity development (RVD), and average power (AP) following very short-term unilateral, reciprocal, concentric isokinetic forearm extension and flexion training in untrained women; and (2) determine whether training the non-dominant arm induced cross-education adaptations in the dominant, non-trained arm. Twelve untrained women (age: 21.7 ± 1.2 yrs) completed four testing and four training visits (pre-test and following 2, 3, and 4 days of training). The testing consisted of three maximal repetitions of the dominant and non-dominant arms at 60°, 180°, and 300°·s⁻¹, with APT and AP calculated as the average of the 3 repetitions and RVD as the fastest repetition. The training consisted of 6 sets of 10 maximal repetitions at 180°·s⁻¹ with the non-dominant arm. The differences in mean values across testing visits for APT, AP, and RVD were determined by separate 2 (Arm) × 2 (Muscle Action) × 3 (Velocity) × 4 (Time [across all testing visits]) repeated measures ANOVA (α ≤ 0.05) with Bonferroni-corrected post hoc comparisons. For the trained arm, there were increases in APT (p < 0.001) following four training visits and AP following three (p = 0.006) and four (p = 0.004) training visits. Furthermore, following four training visits, RVD (collapsed across Arms and Muscle Action) decreased at 180°·s⁻¹ (p = 0.002) and 300°·s⁻¹ (p = 0.005) following four training visits. There were no changes in APT or AP (p = 0.155–1.000) in the non-trained arm, which indicated no cross-education adaptations. These findings suggested that 3–4 days of moderate-velocity, unilateral, reciprocal, isokinetic training elicited early-phase adaptations for APT, RVD, and AP in untrained women, while cross-education adaptations for APT and AP were not observed within this timeframe.