J Strength Cond Res [JOURNAL]
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200 papers
Sex-Specific Immune Cell Mobilization and Recovery After High-Volume Glycolytic Squat Exercise.
Kraemer WJ, Mastro AM, Saenz C … +11 more , Freidenreich DJ, Volk BM, Gomez AL, Fragala MS, Szivak TK, Post EM, Wolf MR, Comstock BA, Hakkinen K, Newton RU, Volek JS
J Strength Cond Res · 2026 Apr · PMID 41983698 · Publisher ↗
Kraemer, WJ, Mastro, AM, Saenz, C, Freidenreich, DJ, Volk, BM, Gomez, AL, Fragala, MS, Szivak, TK, Post, EM, Wolf, MR, Comstock, BA, Hakkinen, K, Newton, RU, and Volek, JS. Sex-specific immune cell mobilization and recov...
Kraemer, WJ, Mastro, AM, Saenz, C, Freidenreich, DJ, Volk, BM, Gomez, AL, Fragala, MS, Szivak, TK, Post, EM, Wolf, MR, Comstock, BA, Hakkinen, K, Newton, RU, and Volek, JS. Sex-specific immune cell mobilization and recovery after high-volume glycolytic squat exercise. J Strength Cond Res XX(X): 000-000, 2026-Acute resistance exercise precipitates a rapid immunological process for surveillance, host protection, and muscle regeneration. In this study, we examined sex-specific differences in leukocyte mobilization after a single bout of high-volume, glycolytic squat resistance exercise. Thirty-four men and 24 women, recreationally active but not resistance-trained, performed 6 sets of 10 repetitions of parallel-depth barbell squats at 65%-10RM on a Smith machine. Venous blood was collected pre-exercise, 15 minutes post, and 60 minutes post-]exercise. Flow cytometry was used to quantify total lymphocytes, T cells (CD3+), T helper (CD4+) and T cytotoxic (CD8+) subsets, B cells (CD19+), natural killer (NK) cells, early activation marker CD69 on multiple subsets, and T-cell regulatory markers CD25 and CD127. Men exhibited greater transient lymphocyte mobilization at 15 minutes postexercise than women (p < 0.05), driven largely by NK cell increases (more than twice the magnitude of women, p < 0.05). CD4+ counts increased in women at 60 minutes (p < 0.05). Both sexes demonstrated significant time-dependent declines in lymphocytes, B cells, and T cells by 60 minutes, with men showing greater modulation of activation markers CD69, CD25, and CD127. Effect sizes indicated moderate-to-very large changes in NK cells, lymphocytes, and T-cell subsets in men, and moderate-to-large changes in NK cells and lymphocytes in women. Moderate - intensity, high-volume resistance exercise elicits robust but partially sex-dependent leukocyte mobilization, particularly in NK cells and early activation markers. These findings highlight the influence of sex on acute immune responses to resistance exercise and the time course of leukocyte mobilization during early recovery.
A Comparison of Single Leg Countermovement Jump Techniques on Jump Performance: Considerations for Test Standardization.
Staton AE, Fahey J, Jones PA
J Strength Cond Res · 2026 Jun · PMID 41961006 · Publisher ↗
Staton, AE, Fahey, J, and Jones, PA. A comparison of single leg countermovement jump techniques on jump performance: considerations for test standardization. J Strength Cond Res 40(6): 650-662, 2026-Single leg countermov...
Staton, AE, Fahey, J, and Jones, PA. A comparison of single leg countermovement jump techniques on jump performance: considerations for test standardization. J Strength Cond Res 40(6): 650-662, 2026-Single leg countermovement jump (SLCMJ) testing is widely used in both sport performance and rehabilitation contexts. However, several inconsistent protocols and various jump techniques have been used across literature. Therefore, the aim of this study was to evaluate 4 variations of the SLCMJ (A: 90° hip and knee flexion, B: 90° knee bend, C: straight limb, D: unrestricted limb), examining the reliability and performance across a range of outcome, kinetic, and temporal metrics with the goal of enhancing test standardization. Twenty-four university sports science students (Mean ± SD ; age = 21.4 ± 3.7 years; height = 176.0 ± 8.2 cm; mass = 71.7 ± 10.8 kg) performed 3 trials of each technique across both limbs, while collecting vertical ground reaction forces from dual force plates and 2D video in the sagittal plane. Technique B demonstrated the highest reliability across most metrics when compared with other techniques (ICC ≥0.80, CV ≤ 13%). Significant differences ( p < 0.05) were observed across all techniques within certain variables. Technique D resulted in greater outcome measures; however, this is achieved through an entirely different strategy relying on angular momentum generated by the swinging free limb and greater work performed by the stance limb hip joint compared with triple lower limb flexion followed by extension involved in the other techniques. Consequently, technique B, limiting the contribution of the free limb, facilitates optimal flexion and extension of the hip, knee, and ankle, thus, is deemed more appropriate for sports performance testing and rehabilitation contexts.
Unraveling the Physical Demands of Rondo Drills: How Different Formats Shape Acceleration and Deceleration Profiles.
Silva H, Monteiro J, Baptista J … +1 more , Beato M
J Strength Cond Res · 2026 May · PMID 41949393 · Publisher ↗
Silva, H, Monteiro, J, Baptista, J, and Beato, M. Unraveling the physical demands of rondo drills: How different formats shape acceleration and deceleration profiles. J Strength Cond Res 40(5): e454-e459, 2026-Accelerati...
Silva, H, Monteiro, J, Baptista, J, and Beato, M. Unraveling the physical demands of rondo drills: How different formats shape acceleration and deceleration profiles. J Strength Cond Res 40(5): e454-e459, 2026-Accelerations and decelerations are a critical component in the assessment of training demands in soccer. The characteristics of accelerations (>3 m·s -2 ) and decelerations (<-3 m·s -2 ) were compared across 3 structured rondo drills (4 vs. 1, 4 vs. 2, 5 vs. 2) performed during 8 minutes in different training sessions. Twenty male elite soccer players (age: 27.1 ± 6.1 years; height: 1.78 ± 0.06 m; body mass: 75.8 ± 7.6 kg) participated for a 10-week period using global navigation satellite systems sampling at 10 Hz. All efforts exceeding the acceleration (>3 m·s -2 ) and deceleration (<-3 m·s -2 ) thresholds were characterized by duration, magnitude, starting and ending speed, and distance covered. Linear mixed models with post hoc comparisons were used to identify differences between drills. Results showed that the frequency of actions increased with the number of players and pitch size. During the 4 vs. 1 format, players attained greater acceleration magnitudes and higher end speeds than the 4 vs. 2 ( p < 0.001) and 5 vs. 2 formats ( p = 0.003 and p = 0.009, respectively). They also accelerated for longer times and distances in 4 vs. 1 than in 4 vs. 2 formats ( p < 0.01). Conversely, fewer differences were reported in decelerations, with 4 vs. 1 format registering higher magnitudes than the other formats ( p < 0.01) and starting from higher speeds than the 4 vs. 2 format ( p = 0.010). During all formats, players started accelerations and ended decelerations from similar, near-stationary speeds (<4 km·h -1 , p < 0.05). These findings highlight that different rondo formats elicit distinct demands, particularly for accelerations. Therefore, rondos should be carefully planned according to session objectives, because their high intensity may contribute to fatigue and muscle damage, reinforcing the need for careful monitoring and integration within training.
The Effects of Augmented Feedback and Encouragement During High-Velocity Resistance Training on Performance, Fatigue, and Function in Older Adults.
Nicholson VP, Cowley N, Weakley J
J Strength Cond Res · 2026 Jun · PMID 41944695 · Publisher ↗
Nicholson, VP, Cowley, N, and Weakley, J. The effects of augmented feedback and encouragement during high-velocity resistance training on performance, fatigue, and function in older adults. J Strength Cond Res 40(6): e63...
Nicholson, VP, Cowley, N, and Weakley, J. The effects of augmented feedback and encouragement during high-velocity resistance training on performance, fatigue, and function in older adults. J Strength Cond Res 40(6): e639-e646, 2026-This study aimed to assess whether kinematic feedback and verbal encouragement enhance movement velocity, motivation, perceived exertion, and physical performance in older adults within session. Fourteen older adults (9 females) with resistance training experience participated in a randomized cross-over trial. After baseline testing, subjects attended 4 resistance training sessions where they completed 3 sets of 10 repetitions on the leg press and bench press at 60% of their 3-repetition maximum. During each training session, subjects were exposed to one of 4 conditions-control (no feedback), visual kinematic feedback, verbal kinematic feedback, or verbal encouragement. The influence of training condition on mean concentric velocity (MCV), motivation, perceived exertion, functional performance, post 24-hour muscle soreness, and fatigue were assessed using a linear mixed model. For leg press, session MCV was significantly ( p < 0.05) higher for all experimental conditions compared with the control condition with effect sizes ranging from 0.16 (95% confidence interval [CI] 0.04-0.27) for verbal encouragement to 0.21 (95% CI 0.09-0.33) for visual and verbal kinematic feedback. For bench press, session MCV was significantly ( p < 0.05) higher for verbal kinematic feedback (ES = 0.20, 95% CI 0.10-0.30) and verbal encouragement (ES = 0.27, 95% CI 0.17-0.37) conditions compared with the control condition. Motivation, perceived exertion, functional performance, muscle soreness, and fatigue were not influenced by the improved movement velocity. These findings demonstrate that kinematic feedback and verbal encouragement can enhance resistance training quality in older adults, without impacting subsequent muscle soreness and function or perceptions of fatigue.
Relative Rest Index Influences Team Performance and Game Outcomes in Recent NBA Competition.
Pinzone AG, Gant RW, Magee MK … +2 more , Barkley JE, Jajtner AR
J Strength Cond Res · 2026 May · PMID 41944691 · Publisher ↗
Pinzone, AG, Gant, RW, Magee, MK, Barkley, JE, and Jajtner, AR. Relative rest index influences team performance and game outcomes in recent NBA competition. J Strength Cond Res 40(5): 585-590, 2026-This investigation aim...
Pinzone, AG, Gant, RW, Magee, MK, Barkley, JE, and Jajtner, AR. Relative rest index influences team performance and game outcomes in recent NBA competition. J Strength Cond Res 40(5): 585-590, 2026-This investigation aimed to assess the relationship between relative rest index (RRI) and team performance and game outcomes during the prior 2 seasons of competition in the National Basketball Association (NBA). All regular season games from the 2022-23 and 2023-24 NBA seasons ( N = 2,461 games) were analyzed. Relative rest index was noted as the discrepancy in rest between games between competing teams, with teams for each game placed into 1 of 5 RRI categories (≤-2, -2 to -0.5, -0.5 to 0.5, 0.5 to 2, and ≥2). Point differential (DIFF), points for (PF), points allowed (PA), and game outcome (W/L) quantified team performance and game outcomes. Multilevel linear (DIFF, PF, PA) and logistic (W/L) mixed effects regression models assessed the influence of RRI on team performance, with further adjustment for competitive season, game location, opponent quality, and season portion. Greater RRI (0.5-2 and ≥2) was positively associated with DIFF and W/L relative to the reference RRI category (≤-2), and teams with RRIs of -0.5 to 2 demonstrated significantly decreased PA relative to the reference category. Finally, playing at home also displayed positive associations with all dependent variables, while playing opponents with greater win percentages over the prior 10 games was negatively associated with all outcomes. There was no observed relationship between RRI and PF or interaction between competitive season and RRI. Based on these data, RRI positively influences team performance and game outcomes in terms of DIFF, PA, and W/L in recent NBA competition.
Accelerometry Insights Into Gym-Based Plyometric Exercises; Evaluating Metrics, Reliability, and Sensor Placement.
McGillivray I, Murphy A, Reid M … +2 more , Perri T, Duffield R
J Strength Cond Res · 2026 Apr · PMID 41944689 · Publisher ↗
McGillivray, I, Murphy, A, Reid, M, Perri, T, and Duffield, R. Accelerometry insights into gym-based plyometric exercises; evaluating metrics, reliability, and sensor placement. J Strength Cond Res XX(X): 000-000, 2025-Q...
McGillivray, I, Murphy, A, Reid, M, Perri, T, and Duffield, R. Accelerometry insights into gym-based plyometric exercises; evaluating metrics, reliability, and sensor placement. J Strength Cond Res XX(X): 000-000, 2025-Quantification of training load is important for athletic performance, yet traditional field-based accelerometry often fails to capture gym-based training demands, particularly in the vertical plane. This study investigates the use of triaxial accelerometry for assessing training load in gym-based plyometric exercises, examining the influence of sensor placement and the reliability of accelerometry-derived metrics. Ten elite youth tennis players (16.0 ± 1.6 years) completed a standardized plyometric session on 2 occasions, consisting of 4 sets of 7 exercises, performed in a superset sequence. Inertial measurement units (IMUs) were worn at 4 anatomical locations (thoracic spine, lumbar spine, left ankle, right ankle), collecting 4 key metrics: peak upward acceleration (PUpAcc), 1D upward PlayerLoad (1DPL-up), 2D PlayerLoad (2DPL), and 3D PlayerLoad (3DPL). Results showed skater hops consistently produced the lowest acceleration magnitudes, whereas altitude landings recorded the highest. Ankle-mounted sensors recorded significantly higher acceleration values than thoracic and lumbar placements ( p < 0.05), confirming the attenuation of signals up the body. PlayerLoad metrics demonstrated strong agreement across sensor locations ( r = 0.50-0.96) in 119/126 comparisons, whereas PUpAcc showed lower associations ( r = 0.01-0.57). Moderate to good reliability values (intraclass correlation coefficient = 0.50-0.84) existed across all metrics, with greater consistency in PlayerLoad metrics compared with PUpAcc. Overall, sensor placement influences accelerometry-derived measures of plyometric activities, with PlayerLoad metrics demonstrating intersensor agreement and reliability across placements. Although thoracic-mounted IMUs capture whole-body motion, they may underestimate lower-limb loading. These preliminary findings support using PlayerLoad metrics for monitoring gym-based plyometrics while highlighting the need for further research into PUpAcc as a measure of impact-related acceleration.
Association Between Single-Leg Heel Rise Performance and Lower Leg, Ankle, and Foot Injuries in Adolescent Ballet Dancers: A Prospective Cohort Study.
Schrefl A, Kolokythas N, Erlacher D … +1 more , Schärli A
J Strength Cond Res · 2026 Apr · PMID 41925545 · Publisher ↗
Schrefl, A, Kolokythas, N, Erlacher, D, and Schärli, A. Association between single-leg heel rise performance and lower leg, ankle, and foot injuries in adolescent ballet dancers: a prospective cohort study. J Strength Co...
Schrefl, A, Kolokythas, N, Erlacher, D, and Schärli, A. Association between single-leg heel rise performance and lower leg, ankle, and foot injuries in adolescent ballet dancers: a prospective cohort study. J Strength Cond Res XX(X): 000-000, 2026-Lower leg, ankle, and foot injuries are common in dancers, yet prospective evidence on performance-based risk factors is limited. The single-leg heel rise (SLHR) test is widely used to assess calf muscle endurance in dance screenings, but its predictive value for injuries remains unclear. At baseline, 70 vocational ballet students (45 females, 25 males) completed the SLHR test. Six movement-quality criteria and a muscular endurance threshold (30 repetitions) were assessed. Medical attention and time-loss injuries were prospectively recorded during a 36-week season. Random forest models identified key predictors, evaluated with logistic regression and receiver operating characteristic analyses. Low eccentric control and pronounced supination emerged as top movement-quality predictors (medical attention: area under the curve [AUC] = 0.75-0.76; time-loss: AUC = 0.80-0.84). Combined with the 30-repetition threshold, this model achieved AUC 0.73 (95% CI: 0.62-0.85), sensitivity 0.60, and specificity 0.80 for medical attention injuries, and AUC 0.69 (95% CI: 0.55-0.82), sensitivity 0.69, and specificity 0.70 for time-loss injuries. Low eccentric control was significantly associated with injury (OR = 4.49, p = 0.013), with nonsignificant trends for the 30-repetition threshold (OR = 2.71) and supination (OR = 1.56). Poor eccentric control, failure to complete 30 repetitions, and pronounced supination were the strongest performance-based indicators of lower leg, ankle, and foot injury risk in adolescent ballet dancers. Monitoring performance deficits in these areas may serve as a practical, low-cost approach to injury risk screening in dance populations. The level of significance was set at p ≤ 0.05.
The Modified 3-Minute All-Out Test Parameters as Predictors of 50-, 100-, and 200-m Front Crawl Official Performance in Trained Swimmers.
Di Gennaro S, Panascì M, Apollaro G … +4 more , Fassone M, Puce L, Ruggeri P, Faelli E
J Strength Cond Res · 2026 Apr · PMID 41925540 · Publisher ↗
Di Gennaro, S, Panascì, M, Apollaro, G, Fassone, M, Puce, L, Ruggeri, P, and Faelli, E. The modified 3-minute all-out test parameters as predictors of 50-, 100-, and 200-m front crawl official performance in trained swim...
Di Gennaro, S, Panascì, M, Apollaro, G, Fassone, M, Puce, L, Ruggeri, P, and Faelli, E. The modified 3-minute all-out test parameters as predictors of 50-, 100-, and 200-m front crawl official performance in trained swimmers. J Strength Cond Res XX(X): 000-000, 2026-In this study, we investigated (a) the relationship between the modified 3-minute all-out test (3mAO mod ) parameters and swimming official performance in 50-, 100-, and 200-m front crawl; (b) the predictive accuracy of critical speed (CS) model; (c) the predictive linear regression (MLR) models incorporating CS, curvature constant (D') or anaerobic speed reserve (ASR), and anthropometry. Twenty-three young swimmers (mean ± SD : age = 17.5 ± 1.9 years, mass = 61.8 ± 7.2 kg, height 1.79 ± 0.08 m) performed the 3mAO mod and, within 6 weeks, competed in 50-, 100-, and 200-m official races. The relationships between 3mAO mod parameters and race times were examined using Pearson's and Spearman's correlation. Race times were predicted using the CS model and MLR, including CS, D', or ASR, sex, age, height, and body mass. Mean absolute error ( MAE ) and paired sample t-tests with Bonferroni corrections were used to compare actual and predicted results. Significance was set at p ≤ 0.05. The correlation between CS and race time increased with the increase in race distance ( r = -0.491 to -0.698) while the correlation between D' and ASR with race time decreased with the increase in race distance (rho = -0.628 to -0.347 and -0.574 to -0.274, respectively). The CS model underestimates race times in the 50- and 200-m races ( p ≤ 0.001, MAE = ±3.33 and ±5.06 seconds, respectively), but not in the 100-m race ( p = 0.070, MAE = ±1.72 seconds). Predictions from MLRs were not significantly different from actual performance in all events ( p = 0.999, ±0.41 seconds < MAE < ±3.56 seconds). The 3mAO mod parameters are related to 50-, 100-, and 200-m performance, supporting their physiologic rationale and, when applied to the developed MLRs, can predict performance with higher accuracy than the CS model, and in a user-friendly manner.
Ready or Not? The Anthropometric and Physical Qualities of Youth Female Rugby League Players in England.
Briscoe T, Darrall-Jones J, Heyward O … +10 more , Sawczuk T, Jones B, Brindle T, Barrow S, Owen C, Heavey K, Mackay L, Cuthbert K, Pinckney M, Scantlebury S
J Strength Cond Res · 2026 Jun · PMID 41925520 · Publisher ↗
Briscoe, T, Darrall-Jones, J, Heyward, O, Sawczuk, T, Jones, B, Brindle, T, Barrow, S, Owen, C, Heavey, K, Mackay, L, Cuthbert, K, Pinckney, M, and Scantlebury, S. Ready or not? The anthropometric and physical qualities...
Briscoe, T, Darrall-Jones, J, Heyward, O, Sawczuk, T, Jones, B, Brindle, T, Barrow, S, Owen, C, Heavey, K, Mackay, L, Cuthbert, K, Pinckney, M, and Scantlebury, S. Ready or not? The anthropometric and physical qualities of youth female rugby league players in England. J Strength Cond Res 40(6): e591-e597, 2026-This study aimed to quantify the physical and anthropometric characteristics of U13 to U17 youth female rugby league players, compare between age categories, and assess relationships between characteristics. Eighty amateur youth female players completed a testing battery including anthropometric (body mass and height) and physical (strength [isometric mid-thigh pull], peak power [counter movement jump], linear speed [40 m sprint], momentum, and high-intensity intermittent running [HIIR] ability [30-15 Intermittent Fitness Test]) qualities. Progressive increases were found in body mass, peak power, strength, speed, momentum, and HIIR ability with age, between age group differences were nonsignificant. Large significant ( p < 0.01) relationships were found between strength and 10 m ( r = 0.54), 20 m ( r = 0.59), 30 m ( r = 0.59), and 40 m ( r = 0.61) momentum. Body mass showed large significant relationships with all momentum distances (10 m: r = 0.54; 20 m: r = 0.59; 30 m: r = 0.59; 40 m: r = 0.61). A large significant ( p = <0.01) relationship was found between strength and peak propulsive power ( r = 0.59). A moderate negative significant ( p < 0.01) relationship was found between body mass and HIIR ( r = 0.49). This study provides novel age-specific reference values for practitioners to assess strengths and areas of development in youth female rugby league players. Findings highlight the need for tailored strength and conditioning programs to ensure players are physically prepared to transition through the development pathway, with practitioners focusing on improving physical readiness for the demands of senior competition.
Acute and Long-Term Effects of Spinning-Based High-Intensity Interval Training on Inducible Nitric Oxide Synthase: A Randomized Controlled Trial.
Uysal A, Soslu R
J Strength Cond Res · 2026 Mar · PMID 41885792 · Publisher ↗
Uysal, A and Soslu, R. Acute and long-term effects of spinning-based high-intensity interval training on inducible nitric oxide synthase: a randomized controlled trial. J Strength Cond Res XX(X): 000-000, 2026-This study...
Uysal, A and Soslu, R. Acute and long-term effects of spinning-based high-intensity interval training on inducible nitric oxide synthase: a randomized controlled trial. J Strength Cond Res XX(X): 000-000, 2026-This study investigated the acute and long-term effects of a 6-week high-intensity interval training (HIIT) spinning program on oxidative stress and inflammatory biomarkers, including inducible nitric oxide synthase (iNOS), in physically active male university students. Subjects were randomly assigned to an experimental group (n = 10), which completed the supervised HIIT intervention, and a control group (n = 10), which maintained their habitual physical activity. Acute physiological stress was elicited using the 30-15 Intermittent Fitness Test (30-15 IFT), and venous blood samples were collected immediately before and after the 30-15 IFT, both before and after the intervention. Analyses included total antioxidant capacity, total oxidant capacity, oxidative stress index, paraoxonase 1, arylesterase, and iNOS. The acute exercise (30-15 IFT) performed did not lead to significant changes in biochemical parameters in either group. Long-term spinning-based HIIT resulted in significant increases in resting pretest values in the experimental group, with total antioxidant capacity significantly increased (p < 0.001), suggesting enhanced endogenous antioxidant defense. This was accompanied by a significant increase in total oxidant capacity (p < 0.007) and oxidative stress index (p < 0.032), indicating elevated oxidative load and systemic redox imbalance. A marked increase in paraoxonase 1 activity (p < 0.001) further reflected adaptive upregulation of antioxidant enzyme systems. However, no significant changes were detected in arylesterase activity or iNOS levels. In conclusion, the findings indicate that spinning-based HIIT elicits selective biochemical responses, particularly enhancing antioxidant status, while inflammatory and enzymatic responses may require higher exercise volume or prolonged exposure to manifest.
Heart Rate Variability After Blood Flow Restriction Resistance Exercise and Traditional Resistance Exercise in Trained Men and Women.
Perlet MR, Mendonça LI, Hosick PA … +2 more , Licameli N, Matthews EL
J Strength Cond Res · 2026 May · PMID 41885789 · Publisher ↗
Perlet, MR, Mendonça, LI, Hosick, PA, Licameli, N, and Matthews, EL. Heart rate variability after blood flow restriction resistance exercise and traditional resistance exercise in trained men and women. J Strength Cond R...
Perlet, MR, Mendonça, LI, Hosick, PA, Licameli, N, and Matthews, EL. Heart rate variability after blood flow restriction resistance exercise and traditional resistance exercise in trained men and women. J Strength Cond Res 40(5): 545-551, 2026-Autonomic nervous system responses are attenuated after blood flow restriction (BFR) resistance exercise vs. traditional resistance exercise (TRE) in men, but women's responses are unknown. The purpose of this investigation is to compare the effects of a single BFR vs. TRE session on HRV. Thirty-nine adults (M=20, W=19, age: 23±4yrs, body mass: 72.3±13.2kg, height: 169±9cm) participated in the study. Barbell back squat 1 repetition maximum (1RM) testing was performed followed by 2 randomized and counterbalanced exercise visits ≥48 hours apart (BFR: 4 sets, 30-15-15-15 repetitions, 30% 1RM, 60 s rest; TRE: 4 sets × 10 repetitions, 70% 1RM, 60 s rest). Pre- and postexercise resting electrocardiograms were analyzed using heart rate variability (HRV) normalized units for low frequency (LF), high frequency (HF), and LF/HF. Two-way repeated measures analysis of variances with sex as a between-subjects effect were analyzed (alpha p < 0.05). Both LF and HF displayed interaction effects (both p < 0.05) with no effect or interaction with sex (all p > 0.05). Post hoc testing found that LF increased and HF decreased postexercise, but with greater effects in the TRE condition (all p < 0.05). Low frequency/HF also increased postexercise, and there was a sex by time interaction (all p < 0.05). Post hoc testing found greater increases in LF/HF postexercise in men than in women ( p < 0.05) across exercise conditions. Both TRE and BFR increased sympathetic activity and decreased parasympathetic activity HRV indices, and the changes were attenuated for BFR in both sexes. However, men have a greater shift toward sympathetic dominance independent of exercise type. These changes in HRV indices may have beneficial applications for exercise training/recovery when trying to reduce autonomic stress.
Internal Load and Fatigue Characteristics in Male Cross-Country Skiers During Summer Training.
Du C, Xu H, Shi J … +3 more , Wei J, Quan H, Zhu T
J Strength Cond Res · 2026 Jul · PMID 41885788 · Publisher ↗
Du, C, Xu, H, Shi, J, Wei, J, Quan, H, and Zhu, T. Internal load and fatigue characteristics in male cross-country skiers during summer training. J Strength Cond Res 40(7): e727-e735, 2026-This study aims to measure the...
Du, C, Xu, H, Shi, J, Wei, J, Quan, H, and Zhu, T. Internal load and fatigue characteristics in male cross-country skiers during summer training. J Strength Cond Res 40(7): e727-e735, 2026-This study aims to measure the internal load and fatigue responses of cross-country skiers during a 3-week summer training period, comparing differences across various training methods and their combinations. Twelve male cross-country skiers participated in this longitudinal observational study. We recorded the internal load for each training session via Firstbeat sport devices on the basis of the Banister training impulse (bTRIMP) model. The fatigue assessment metrics included the resting heart rate (RHR) and quick recovery test percentage (QRT%). Physiological performance was assessed by measuring maximal oxygen consumption (V̇ o2 max). Statistical significance was considered at p < 0.05. The internal load progressively decreased over the 3-week period. The bTRIMP during the competition session was significantly greater than that during the routine training session ( p < 0.05). Among the different training modalities and their combinations, strength-related sessions produced the lowest bTRIMP values, followed by running and competition, whereas roller skiing presented the highest values. Resting heart rate and QRT% displayed different temporal patterns. No significant differences in RHR were found after different training modalities ( p > 0.05). However, the postcompetition QRT% was significantly lower than the post-training value ( p < 0.05). Neither RHR nor QRT% significantly differed after various combined training sessions ( p > 0.05). A moderate negative correlation was observed between RHR and QRT% ( r = -0.361, p < 0.001). V̇ o2 max did not significantly differ ( p > 0.05). Overall, although there was considerable variation in the internal load across different types of sessions, no significant cumulative signs of fatigue were detected.
Differences in Critical Torque Among Untrained, Resistance-Trained, and Aerobic-Trained Young Individuals.
Chesbro G, Larson DJ, Wenger MJ … +2 more , Black CD, Larson RD
J Strength Cond Res · 2026 Jun · PMID 41879264 · Publisher ↗
Chesbro, G, Larson, DJ, Wenger, MJ, Black, CD, and Larson, RD. Differences in critical torque among untrained, resistance-trained, and aerobic-trained young individuals. J Strength Cond Res 40(6): e584-e590, 2026-Critica...
Chesbro, G, Larson, DJ, Wenger, MJ, Black, CD, and Larson, RD. Differences in critical torque among untrained, resistance-trained, and aerobic-trained young individuals. J Strength Cond Res 40(6): e584-e590, 2026-Critical torque (CT) is thought to be a key representation of the relationship between performance and fatigue, yet no research to date has examined CT relative to the type of exercise training. This study aimed to examine differences in CT based on training status (TS). Thirty-eight individuals participated in the study and were split into 3 groups: 17 Untrained (UT), 9 Aerobic Trained (AT), and 12 Resistance Trained (RT), based on self-reported training time. The subjects completed a critical torque test. The 5-minute maximal protocol consisted of 30 six-second maximal contractions followed by a 4-second rest. Statistical significance was set a priori at p < 0.05. The RT group (365.39 N·m ± 77.44) had higher maximal strength than the AT (271.23 N·m ± 78.91; p = 0.015) and UT (274.64 N m ± 76.71, p = 0.030) groups. The AT group (149.73 N m ± 35.51) had a higher absolute CT than the UT group (114.72 N m ± 25.61, p = 0.029). When CT was normalized to maximal voluntary contraction (MVC), the AT group (56.37% ± 11.36) had a higher CT than the RT (37.65% ± 7.60; p = 0.003) and UT (43.07% ± 8.69; p < 0.001) groups. In addition, there was a between-group difference in impulse above critical torque (IACT) where the RT group (10,146.76 N·m·s ± 2,886.51) had higher IACT than the AT group (6,578.65 N·m·s ± 3,823.71; p = 0.028). To our knowledge, this is the first study to directly assess the differences in CT based on TS. Our data suggest that TS affects CT assessments. These findings are important for researchers to consider because they affect the common assessment of CT when assigning the load for a fatiguing task using MVC.
Decrements in Neuromuscular Function Are Reduced Following Low-Load Continuous Blood Flow Restriction Exercise Compared With High-Load Resistance Exercise.
Davids CJ, Raastad T, Geneau MC … +5 more , James LP, Lichtwark G, Coombes JS, Peake JM, Roberts LA
J Strength Cond Res · 2026 May · PMID 41875053 · Publisher ↗
Davids, CJ, Raastad, T, Geneau, MC, James, LP, Lichtwark, G, Coombes, JS, Peake, JM, and Roberts, LA. Decrements in neuromuscular function are reduced following low-load continuous blood flow restriction exercise compare...
Davids, CJ, Raastad, T, Geneau, MC, James, LP, Lichtwark, G, Coombes, JS, Peake, JM, and Roberts, LA. Decrements in neuromuscular function are reduced following low-load continuous blood flow restriction exercise compared to high-load resistance exercise. J Strength Cond Res 40(5): 552-559, 2026-The aim of this study was to quantify neuromuscular fatigue during and following resistance exercise protocols varying in load and blood flow restriction (BFR) application. Twelve strength-trained male subjects performed 4 sets of squat exercises under 4 conditions: (a) low-load resistance exercise (LL-RE, 30% one-repetition maximum [1RM]), (b) high-load resistance exercise (HL-RE, 70% 1RM), (c) LL-RE with continuous BFR (BFR-C), and (d) LL-RE with intermittent BFR (BFR-I). Neuromuscular fatigue markers included repetition velocity, isometric knee extensor torque, jump performance, and quadriceps contractile properties. Effort perceptions were also recorded. Statistical significance was set at p < 0.05. Repetition velocities slowed with HL-RE (-8 ± 5%) and BFR-C (-4 ± 11%), significantly differing from LL-RE (7 ± 5%) and BFR-I (3 ± 5%). Effort ratings increased significantly across all conditions (all p < 0.01), with higher ratings observed during HL-RE and BFR-C compared with LL-RE and BFR-I for all 4 sets (all p < 0.01). At 60 minutes postexercise, knee extensor torque was reduced more with HL-RE (-8 ± 10%) than BFR-C (-6 ± 11%), and evoked contraction torque showed a similar pattern (HL-RE: -18 ± 12%; BFR-C: -5 ± 12%). Jump height declined across all conditions but was significantly greater following HL-RE (-13 ± 6%). Both HL-RE and BFR-C induced neuromuscular fatigue, slowing repetition velocities and elevating effort perceptions, but impairments were more pronounced with HL-RE after 60 minutes. Blood flow restriction-C may be a valuable alternative in athletic contexts where loading and/or postexercise fatigue must be managed.
Effects of Short-Duration Cycling After Resistance Exercise on Aortic Stiffness and Next-Day Recovery in Strength-Trained Men.
Vondrasek JD, Brown JE, Grosicki GJ … +1 more , Flatt AA
J Strength Cond Res · 2026 May · PMID 41875047 · Publisher ↗
Vondrasek, JD, Brown, JE, Grosicki, GJ, and Flatt, AA. Effects of short-duration cycling after resistance exercise on aortic stiffness and next-day recovery in strength-trained men. J Strength Cond Res 40(5): 536-544, 20...
Vondrasek, JD, Brown, JE, Grosicki, GJ, and Flatt, AA. Effects of short-duration cycling after resistance exercise on aortic stiffness and next-day recovery in strength-trained men. J Strength Cond Res 40(5): 536-544, 2026-We aimed to determine whether 10 minutes of cycling after resistance exercise (RE) mitigates acute aortic stiffening and affects next-day recovery markers in trained men. Twelve men (age: 23 ± 4 years, BMI: 26.7 ± 3.4 kg/m 2 , RE experience: 4 ± 2 years) completed identical upper-body RE sessions on separate days, with and without post-RE cycling (70% age-predicted maximal heart rate). Carotid-femoral pulse wave velocity (cfPWV) was assessed pre-RE, 5 minutes post-RE, and again 15-, 25-, and 40-minute postcycling intervention or time-matched control. Heart rate variability and maximal mean concentric barbell bench press velocity (MCV) were assessed pre-RE and 24 h post-RE. Perceived recovery and soreness were assessed 24 hours post-RE. Significance was set at p ≤ 0.05. No condition × time interaction ( p = 0.16) was found for cfPWV. Irrespective of condition, 5-minute post-RE cfPWV (6.0 ± 0.7m/s) was higher than all other time points (5.5 ± 0.6-5.6 ± 0.6 m/s; ps < 0.0001). Greater cfPWV reductions at 40 minutes post-RE, relative to immediately post-RE, correlated with lower fitness (i.e., lower relative cycling power output, [W/kg]; r = 0.732, p < 0.01) even after adjusting for increases in cfPWV 5 minutes post-RE. Heart rate variability and MCV were not different from pre-RE at 24 hours ( ps > 0.05). Similarly, perceptual measures did not differ between conditions at 24 hours ( ps > 0.05). A 10-minute cycling bout post-RE did not alter aortic stiffness or next-day recovery responses but was more effective in reducing cfPWV in subjects with lower aerobic fitness.
Mood Disturbances, Eating Attitudes, and Their Effect on Body Composition Changes in Elite Female Athletes.
Tsukahara Y, Torii S, Taniguchi Y … +4 more , Kusakabe T, Murakami H, Yamasawa F, Akama T
J Strength Cond Res · 2026 Jul · PMID 41875046 · Publisher ↗
Tsukahara, Y, Torii, S, Taniguchi, Y, Kusakabe, T, Murakami, H, Yamasawa, F, and Akama, T. Mood disturbances, eating attitudes, and their effect on body composition changes in elite female athletes. J Strength Cond Res 4...
Tsukahara, Y, Torii, S, Taniguchi, Y, Kusakabe, T, Murakami, H, Yamasawa, F, and Akama, T. Mood disturbances, eating attitudes, and their effect on body composition changes in elite female athletes. J Strength Cond Res 40(7): e721-e726, 2026-Body composition is an important factor in athletic performance at high levels. However, seasonal changes and the effects of mood disturbances and eating attitudes in elite female athletes are not fully understood. In this study, measurements were taken during the season and off-season from 115 athletes. Athletes also completed the Profile of Mood States second edition and the Eating Attitudes Test (EAT-26). Compared with the on-season, body mass did not significantly change in the off-season (54.3 ± 4.4 kg during season and 54.5 ± 4.2 kg during off-season, p = 0.085). However, body fat percentage decreased significantly during the off-season compared with the on-season (17.8 ± 3.8% during on-season and 17.1 ± 3.2% during off-season, p = 0.004). Although anger-hostility scores increased during the off-season, other domains and EAT-26 scores remained stable. Multiple linear regression analysis revealed that body fat percentage decreased in older athletes (coefficient = -2.829, 95% confidence interval [CI] -4.466 to -1.192, p < 0.001) and increased in those with lower tension-anxiety (TA; coefficient = 0.739, 95% CI 0.172 to 1.306, p = 0.011) and higher fatigue-inertia (FI) (coefficient = -0.572, 95% CI -1.106 to -0.038, p = 0.036). These findings suggest that psychological stress indicators, such as TA and FI, may be associated with changes in body fat percentage. Overthinking and mood disturbances may have a negative physiological impact, highlighting the importance of psychological monitoring in elite athletes.
Validity and Reliability of an AI-Based Jump Height App vs. Infrared Contact Mat: Minimal Influence of Skin Pigmentation Under Standardized Lighting.
Ríos-Gallardo PT, Carranza-García LE, Dietze-Hermosa M … +4 more , Gonzalez MP, Balsalobre-Fernández C, Dorgo S, Montalvo S
J Strength Cond Res · 2026 Mar · PMID 41875017 · Publisher ↗
Ríos-Gallardo, PT, Carranza-García, LE, Dietze-Hermosa, M, Gonzalez, MP, Balsalobre-Fernández, C, Dorgo, S, and Montalvo, S. Validity and reliability of an AI-based jump height app vs. infrared contact mat: minimal influ...
Ríos-Gallardo, PT, Carranza-García, LE, Dietze-Hermosa, M, Gonzalez, MP, Balsalobre-Fernández, C, Dorgo, S, and Montalvo, S. Validity and reliability of an AI-based jump height app vs. infrared contact mat: minimal influence of skin pigmentation under standardized lighting. J Strength Cond Res XX(X): 000-000, 2026-This study examined the validity, reliability, and visual robustness of an artificial intelligence-based mobile application (My Jump Lab) for measuring countermovement jump (CMJ) and squat jump (SJ) height across a heterogeneous athletic population. A dual-session, test-retest design was implemented with 43 recreationally active adults (age: 21.2 ± 2.4 years), who performed 3 maximal-effort SJ and CMJ trials per session. Jump height was concurrently recorded using a force platform and the AI-based app. Validity was assessed through linear regression and Bland-Altman analyses, and reliability was evaluated using intraclass correlation coefficients (ICC) and coefficient of variation (CV). A linear mixed-effects model tested whether body dimensions, lighting conditions, or skin pigmentation influenced AI accuracy. The AI systematically overestimated jump height (bias = +2.81 cm, p < 0.001), yet showed excellent concurrent validity (R2 = 0.94), strong within-session reliability (ICC = 0.97; CV = 4.2%), and good between-session reliability (ICC = 0.89). Countermovement jump values were more consistent than SJ. No significant effects were observed for lighting or pigmentation (p > 0.05). Although absolute error was higher in SJ, AI-based estimates remained stable across conditions. The level of significance was set at p ≤ 0.05. In conclusion, the AI-based app provides a valid and reliable alternative for field-based jump assessment. However, practitioners should interpret absolute values cautiously, especially for SJ. These findings support the utility of computer vision and AI to democratize biomechanical assessments without sacrificing measurement quality.
Monitoring Seasonal Changes in Body Composition and Physical Performance in Elite Female Soccer Players.
Zabaloy S, Villaseca-Vicuña R, Freitas TT … +1 more , Loturco I
J Strength Cond Res · 2026 Apr · PMID 41874533 · Publisher ↗
Zabaloy, S, Villaseca-Vicuña, R, Freitas, TT, and Loturco, I. Monitoring seasonal changes in body composition and physical performance in elite female soccer players. J Strength Cond Res 40(4): e425-e431, 2026-This study...
Zabaloy, S, Villaseca-Vicuña, R, Freitas, TT, and Loturco, I. Monitoring seasonal changes in body composition and physical performance in elite female soccer players. J Strength Cond Res 40(4): e425-e431, 2026-This study aimed to investigate seasonal changes in body composition and physical performance in elite female soccer players. Thirty-two professional players (age: 26 ± 4 years) from the same club were assessed at 3 time points (TPs): preseason (TP1), early in the season (TP2), and midseason (TP3). For approximately 6 months, players completed anthropometric and body composition assessments, and physical tests including the countermovement jump (CMJ), squat 1 repetition maximum (squat 1RM), 10-m sprint, and Yo-Yo Intermittent Recovery Test Level 1 (YYIR1). Mean propulsive velocity (MPV) during the squat exercise was assessed at absolute loads of 30 and 40 kg. Significant and gradual improvements were observed in ∑6 skinfolds, fat mass percentage, and muscle mass percentage (p < 0.02). Mean propulsive velocity at 30 and 40 kg increased significantly throughout the season (p < 0.039), while 1RM and relative strength remained stable. Countermovement jump, 10-m sprint, and YYIR1 performance improved significantly from TP1 to TP3 (p < 0.003), with YYIR1 showing very large gains (≈25%). These adaptations occurred despite a congested competition schedule, with players participating in 18 matches across the study period. Overall, the findings indicate that a multicomponent training program combining resistance, power, speed, and endurance sessions can improve body composition, neuromuscular qualities, and endurance performance during the early and midseason stages in professional female soccer players. The results provide novel insights into performance monitoring in female soccer and highlight the importance of integrating diverse physical training strategies throughout the competitive season.
Optimizing Performance in Women Futsal: Impact of Neuromuscular Training on Speed, Change of Direction, and Repeated Sprint Ability.
Albalad-Aiguabella R, Mainer-Pardos E, Gadea-Uribarri H … +2 more , Vicente-Rodríguez G, Muniz-Pardos B
J Strength Cond Res · 2026 Apr · PMID 41874532 · Publisher ↗
Albalad-Aiguabella, R, Mainer-Pardos, E, Gadea-Uribarri, H, Vicente-Rodríguez, G, and Muniz-Pardos, B. Optimizing performance in women futsal: impact of neuromuscular training on speed, change of direction, and repeated...
Albalad-Aiguabella, R, Mainer-Pardos, E, Gadea-Uribarri, H, Vicente-Rodríguez, G, and Muniz-Pardos, B. Optimizing performance in women futsal: impact of neuromuscular training on speed, change of direction, and repeated sprint ability. J Strength Cond Res 40(4): e385-e396, 2026-This study aimed to examine the effects of 2 different weekly volumes of a neuromuscular training program (NMTP) on sprinting, change of direction (COD), and repeated sprint ability (RSA) in well-trained female futsal players. Thirty-eight players from 3 second division Spanish League teams were assessed pre- and postintervention using photoelectric cells for linear sprint times (5, 10, 15, and 25 m), COD tests (V-Cut, L-Run right and left, and modified 505), and RSA. Subjects completed a 12-week NMTP performed once per week (EG1; n = 14), twice per week (EG2; n = 12), or continued traditional resistance training as a control group (CG; n = 12). EG1 significantly improved 10 m (p = 0.04) and 15 m (p = 0.01) sprint times, V-Cut (p < 0.01), and L-Run right and left (p < 0.01). Two-factor repeated measures analysis of variance showed no significant differences in mean change between EG1 and EG2 for any sprint, COD, or RSA measure (all p > 0.05), indicating that increasing to 2 weekly NMTP sessions did not provide additional benefits. Control group showed reductions in sprint performance for 10 and 25 m, in 505 left, and in all RSA sprints. These findings indicate that 1 weekly NMTP session can improve sprint and COD performance in well-trained female futsal players, whereas increasing to 2 weekly sessions does not provide further benefits. In contrast, continuing traditional resistance training may reduce sprint and RSA performance, highlighting the importance of incorporating sport-specific neuromuscular training into in-season conditioning programs.
The External Game Demands of Professional, Male Basketball Players According to Playing Position and Playing Role: A Multiseason Analysis in the Australian National Basketball League.
Shirley SK, Scanlan AT, Guy JH … +3 more , Bartlett RJ, Bowe SJ, Elsworthy N
J Strength Cond Res · 2026 Apr · PMID 41874531 · Publisher ↗
Shirley, SK, Scanlan, AT, Guy, JH, Bartlett, RJ, Bowe, SJ, and Elsworthy, N. The external game demands of professional, male basketball players according to playing position and playing role: A multiseason analysis in th...
Shirley, SK, Scanlan, AT, Guy, JH, Bartlett, RJ, Bowe, SJ, and Elsworthy, N. The external game demands of professional, male basketball players according to playing position and playing role: A multiseason analysis in the Australian National Basketball League. J Strength Cond Res 40(4): 460-467, 2026-This observational study provides a contemporary and novel analysis of the external game demands experienced by professional, male basketball players competing in the Australian National Basketball League (NBL) and compares these demands between playing roles and playing positions. Twenty-two professional, male basketball players (age: 27.0 ± 3.3 years) were monitored over 2 competitive seasons between 2021 and 2023 using microsensor technology (T6; Catapult Sports). Players were categorized according to playing role (starting, bench) and playing position (frontcourt, backcourt). Accumulated (total) and relative (per minute) external game demands were calculated for PlayerLoad in addition to total and high-intensity inertial movement analysis variables during live playing time. External game demands were quantified as estimated marginal means (95% confidence limits) and compared between playing roles and playing positions via linear mixed model and Cohen's d effect size analyses. Significance was set at p ≤ 0.05. Starting players experienced higher accumulated external game demands than bench players across most variables (p < 0.05, d = 0.30-1.87), whereas relative external game demands were similar between playing roles (p > 0.05, d = 0.01-0.44). Likewise, external game demands were comparable between playing positions across variables (p > 0.05, d = 0.03-1.15). These findings demonstrate that only accumulated external game demands differ between playing roles, whereas homogeneity in external game demands appear to exist between generalized playing positions. These foundation data in the Australian NBL may inform training and recovery protocols among end-users working in this competition to ensure players are optimally prepared for competition according to their specific requirements.
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