Clark, JR, McKune, AJ, and Wood, PS. A self-regulated submaximal ergometer training session as a field test to assess performance, aerobic fitness, and recovery in elite rowers. J Strength Cond Res 40(7): e736-e745, 2026-Regularly assessing the response to training may be burdensome in high-level athletes, especially during intensified preparation periods. This study investigated whether a self-regulated 6-km submaximal rowing ergometer training session could double as a field test (6SRT) to estimate performance, aerobic fitness, and recovery in elite rowers. In a cross-sectional design, 2-km ergometer time trial (TT) time, lactate threshold power output (LT PO), self-reported total recovery (TR), and 6SRT responses were measured in 44 male open and lightweight category rowers from a national training center. Mean PO and exercise heart rate (HRex) were used to derive the PO:HRex intensity ratio in the 6SRT, and rating of perceived exertion (RPE) and HR recovery (HRR) were recorded. In 33 subjects, correlation identified clear predictors of 2-km TT time and LT PO, but not TR. Multiple regression models estimating 2-km TT time (R2 = 0.80) and LT PO (R2 = 0.79) were cross-validated in 11 subjects. Measured vs. predicted 2-km TT time (using PO:HRex, RPE, and category) and LT PO (using PO:HRex and category) showed r: 0.93; standard error of estimation (SEE): 5.1 seconds (1.4%); 95% limits of agreement (LOA): -12.4 to 9.6 seconds (-3.3 to 2.6%), and r: 0.85; SEE: 12 W (4.2%); 95% LOA: -22 to 28 W (-5.8 to 7.4%), respectively. Although agreement with measured values is insufficient for detecting small differences, the 6SRT shows potential as a training test set enabling practitioners to reasonably accurately estimate performance and aerobic fitness, but not recovery, in elite rowers.

Jaén-Carrillo, D, Cartón-Llorente, A, García-Ramos, A, and Santos, L. Mechanical variables derived from submaximal back squat performance are positively associated with running performance in highly trained endurance athletes. J Strength Cond Res 40(7): 799-806, 2026-The purpose of this study was to determine the relationship between lower-body maximal neuromuscular capacities and endurance running performance. Fifteen highly trained endurance runners completed 3 sessions. The first determined one-repetition maximum (1RM) in the half squat. The second assessed maximal neuromuscular capacities ( L0 : maximal theoretical load; V0 : maximal theoretical velocity; Aline : area under the load-velocity relationship line, used as a proxy for maximal power) and strength deficit (mean propulsive velocity [MPV] at 40-90% 1RM). The third measured running speed, ground contact time, cadence, and leg stiffness during 9- and 3-minute time trials. Pearson correlation analyses, with the significance level set at p < 0.05, revealed a positive association between Aline and leg stiffness during both the 9-minute ( r = 0.552, p = 0.033) and 3-minute ( r = 0.580, p = 0.023) time trials. In addition, leg stiffness was also significantly associated with strength deficit, showing moderate correlations with MPV at 60% 1RM ( r = 0.585, p = 0.022) and 70% 1RM ( r = 0.555, p = 0.032) in the 9-minute trial, and at 50% 1RM ( r = 0.611, p = 0.016), 60% 1RM ( r = 0.685, p = 0.005), 70% 1RM ( r = 0.653, p = 0.008), and 80% 1RM ( r = 0.552, p = 0.033) in the 3-minute trial. Given the established association between leg stiffness and running efficiency, long-distance runners may benefit from incorporating explosive strength training with moderate to high loads (50-80% 1RM) to enhance power output and maintain propulsive force during endurance running.

Li, H, Yang, Q, and Wang, B. Effects of different training-intensity distribution models on maximal oxygen uptake and time-trial performance in endurance athletes: A Bayesian network meta-analysis. J Strength Cond Res 40(7): e755-e764, 2026-Training intensity distribution (TID) describes how an athlete's total training time is allocated across low-, moderate-, and high-intensity zones. Training intensity distribution models are central to endurance training, but their relative effectiveness across key performance outcomes remains unclear. We conducted a Bayesian network meta-analysis to compare the effects of common TID models on maximal oxygen uptake (V̇ o2 max) and time-trial (TT) performance. Randomized controlled trials were retrieved from PubMed, Web of Science, EBSCO, the Cochrane Library, and Scopus, with risk of bias assessed using the Cochrane tool. Compared with polarized training, no other TID model showed a definite advantage for improving V̇ o2 max or TT performance, because all 95% credible intervals crossed zero. However, Bayesian posterior ranking indicated that lactate-threshold training (THR) was most likely to be the optimal model for V̇ o2 max (rank-1 probability = 65.4%, SUCRA = 84.8%), whereas high-intensity interval training (HIT) was most likely to optimize TT performance (rank-1 probability = 53.9%, SUCRA = 81.5%). Age, training status, intensity-quantification method, intervention duration, and sex were identified as potential moderators. Cluster analysis showed both shared and sport-specific TID patterns. Overall, coaches should tailor TID strategies to athlete characteristics and sport demands, with THR and HIT emerging as the most promising options for targeting V̇ o2 max and TT performance, respectively.

To investigate performance, recovery, sleep, nocturnal physiology, ovarian hormone concentrations, and menstrual cycle symptoms within and between menstrual cycle phases and establish within-phase reliability of these measures. Twenty naturally cycling, trained female participants (age 27 ± 5 yr) completed a repeated measures study design. Serum estradiol and progesterone concentrations, countermovement jumps, isometric mid-thigh pulls, a repeated 5 km cycle time trial, and two nights of sleep architecture were measured in phases one, three, and four of two menstrual cycles. Sleep and wake measures from activity monitoring, nocturnal heart rate (HR) measures from the Oura Ring, and menstrual cycle symptoms were monitored daily. Statistical analyses included linear mixed models and reliability measures. Estradiol concentrations were significantly lower in phase one versus three, one versus four, and three versus four ( P < 0.001 to 0.04) in both menstrual cycles. Progesterone concentrations were significantly lower in phase one versus four, and three versus four ( P < 0.001) in both menstrual cycles. Symptoms were significantly higher in phase one versus three and four ( P < 0.001) in cycle one only. No significant differences between phases were found for performance, recovery, and sleep in either cycle, except for the nonrapid eye movement stage three (N3%) sleep in cycle two. Nocturnal average HR was significantly lower ( P < 0.001) and HR variability higher ( P < 0.001) in phase one versus four in both cycles. Ovarian hormone concentrations were highly variable within each phase (coefficients of variance 28%-95%), while performance and recovery demonstrated minimal variability in both cycles. Performance, recovery, and sleep in trained female participants remained consistent despite ovarian hormone fluctuations. Consequently, practitioners should test athletes when convenient, using accurate and reliable assessments rather than synchronizing testing with specific menstrual cycle phases.

Carbohydrate loading (CL) has long been a cornerstone of endurance nutrition, yet its true efficacy remains uncertain. Although CL is commonly associated with improved time to fatigue and modest performance gains in exercise lasting ∼90-240min, few studies have employed double-blind, placebo-controlled (DBPC) designs. Given that belief and expectation can independently influence performance, it remains unclear whether reported benefits reflect CL or placebo effects. We systematically evaluated the use of blinding and in-exercise carbohydrate provision in CL research. Of 14 identified studies, only two were DBPC trials. Notably, only four provided carbohydrates during exercise. Both DBPC studies included appropriate in-exercise carbohydrate intake and reported no evidence of performance benefit of CL. Of the remaining two studies that provided carbohydrates during exercise, CL showed a positive performance effect; however, the effect size was moderate and comparable to that reported for placebo nutritional interventions (Cohen's d ≈ 0.35). Comparisons across CL studies are heterogeneous in design, including differences in performance test type (time to exhaustion vs. time trial), which points to the need for more research in standardized conditions. The current evidence therefore calls for a re-evaluation of whether CL in the 24-48hr before competition enhances performance once placebo effects are accounted for and in-race fueling is optimized. This commentary highlights the need for more DBPC studies and the potential role of placebo (such as belief) in observed performance outcomes. We propose future research directions to better isolate the independent contributions of CL and placebo effects in endurance performance.

Sex differences in pacing profile and day-to-day variability have been underexplored. Therefore, this study investigated potential sex differences in pacing profile, risk-taking behavior, and pacing reliability during a 4-km cycling time trial. Men and women present similar pacing and assume similar risk of premature trial interruption during a 4-km cycling time trial. In addition, it was hypothesized that men and women might present comparable performance and pacing reliability. Cross-sectional study. Level 4. A total of 32 cyclists (16 men and 16 women) performed 2 4-km cycling time trials on separate days. Power output and ratings of perceived exertion were recorded during the trials. To quantify the risk of premature time-trial interruption, the hazard score was calculated as the product of the rating of perceived exertion and the remaining distance. There were no sex differences in power output distribution or hazard score during the 4-km cycling time trial (P > 0.05), with both men and women presenting a "U-shaped" pacing profile. In addition, men and women exhibited similar endurance performance reliability between trials (P > 0.05). However, the day-to-day coefficient of variation for power output distribution ranged from 3.5% to 7.2% in women and from 1.9% to 6.3% in men, indicating slightly greater day-to-day variability in the pacing profile for women. Men and women exhibit similar pacing profiles, risk-taking behavior, and endurance performance reliability during a 4-km cycling time trial. However, women seem to demonstrate greater day-to-day pacing profile variability than men. The present findings provide insights that enable more accurate monitoring and prescription of training protocols in female cyclists.

Research on the acute effects of β-alanine supplementation has primarily focused on performance outcomes, with limited attention to the underlying physiological mechanisms. This study aimed to investigate the acute effects of two β-alanine doses on performance, mechanical output, and acid-base balance during a 10 min cycling time trial (10'-TT), and to explore the relationship between buffering-related variables and performance. Eighty-five recreational cyclists performed a 10'-TT under indoor conditions before (control) and following the acute ingestion of β-alanine (moderate-dose β-alanine 10 g-BAM; high-dose β-alanine 20 g-BAH) or placebo (PLA), with each condition tested on separate days. Data were analyzed using two-way repeated-measures ANOVA and correlation analyses. No significant differences were observed in performance variables (distance, speed, cadence, or heart rate; p ≥ 0.751). However, total external mechanical work (kJ) was significantly reduced following acute supplementation (p = 0.028). Notably, the BAM condition reduced the mechanical cost of exercise without impairing performance, and this effect was moderately associated with changes in bicarbonate levels. Acute β-alanine supplementation did not improve performance outcomes but may alter buffering-related physiological responses associated with reduced mechanical work during high-intensity cycling exercise. These findings highlight the relevance of buffering-related mechanisms, particularly bicarbonate dynamics, in modulating the mechanical cost (work performed relative to performance achieved) of high-intensity exercise.

Rather than viewing dual-task interference solely as a fixed structural limitation, recent strategic models suggest that it should be dynamically managed through active goal-protection strategies, such as task shielding. This study investigated how strategic control recruitment interacts with overall cognitive load and explicit task-priority instructions in asymmetric task environments. Twenty-four healthy adults performed two distinct paradigms: a low cognitive load paradigm (simple reaction task + go/no-go task) and a high cognitive load paradigm (simple arrow task + flanker arrow task), each composed of low- and high-difficulty components. The task priority was manipulated toward the lower-difficulty component, the higher-difficulty component, or equally between the two. Instructional compliance was objectively verified through a validation analysis of reaction times in 1-second lead time trials. The results revealed that, in the high cognitive load paradigm, explicit priority instructions significantly redistributed dual-task interference. Prioritizing one task component successfully reduces its performance decrement at the expense of the non-prioritized task. Conversely, the low-cognitive-load paradigm exhibited no significant differences in dual-task interference across priority conditions. These findings suggest that the implementation of strategic control, such as "task shielding," is affected by cognitive load. Although many dual task combinations exist, task shielding and task priority shifts may emerge in paradigms that impose a sufficiently high cognitive load to necessitate proactive goal protection.

Schwalm, LC, Pilat, C, Nolte, S, Gatterer, H, Krüger, K, and Hollander, K. Does hypoxic training improve running economy and performance of elite and competitive middle- and long-distance runners? A systematic review with meta-analysis of randomized controlled trials. J Strength Cond Res XX(X): 000-000, 2026-Altitude training (AT) is used to improve endurance performance in competitive running. The aim of this systematic review was to determine whether hypoxic training interventions affect running economy (RE) and performance of competitive runners compared with training under normoxic conditions. Randomized controlled trials (RCTs) were included if they (a) consisted any exposure to hypoxia over a period of ≥3 weeks while performing an endurance exercise training during the same period, and (b) included RE, time trial (TT), time-to-exhaustion (TTE) tests or V̇o2max under normoxic conditions, and (c) included competitive distance runners. Sixteen RCTs were included in the review and 13 in the meta-analysis. The number of subjects in the included studies were n = 182 (11% women) for RE, n = 95 (19% women) for V̇o2max, n = 134 for TT (14% women), and n = 81 (4% women) for TTE. The meta-analysis showed no impact of AT on RE (standardized mean difference (SMD): -0.2; 95% confidence interval (CI): -0.58-0.19; p = 0.31; I2 = 33%). No impact was found for V̇o2max (SMD: 0.33; 95% CI: -0.72 to 1.37; p = 0.54; I2 = 82%) and TT (SMD: -0.34; 95% CI: -0.80 to 0.13; p = 0.16; I2 = 42%). Altitude training showed superiority in improving TTE compared with normoxic training (SMD: 0.89; 95% CI: 0.12- 1.66; p = 0.02; I2 = 56%). Available RCTs do not support an improvement in RE, V̇o2max, and TT when AT was compared with normoxic training. Future RCTs should specifically investigate effects of AT on RE in elite athletes.

Hand and wrist injuries are increasingly prevalent and impact individuals' abilities to participate in society and generate income. Attrition in the hand and wrist trauma treatment time course and trials is a recognised issue, with patients disengaging from follow-up due to various logistical and socioeconomic barriers. While several studies have addressed this, the timeline and causes of attrition in trials remain inconsistent. This meta-analysis aims to evaluate the attrition rates among patients with hand and wrist trauma across all prospective randomised controlled trials (RCTs), identifying critical time points for attrition, at-risk patient populations, and comparing surgical versus non-surgical interventions. The databases Embase, PubMed, and CENRAL will be searched. Abstracts will be screened by two persons independently to identify eligible studies. The systematic review will include prospective randomised controlled trials in participants with hand and/or wrist trauma. The review will consider patient demographics and proportions of attrition rates at time frames of 30days, 90days, 6months, and 12months. The meta-analysis will compare attrition time frame considering patient demographics, intervention and injury types, and documented attrition reasons. The Cochrane risk-of-bias tool 2 will be used to assess the risk of methodological bias in the randomised controlled trials. This systematic review and meta-analysis will address the critical gap in understanding attrition rates in hand/wrist trauma research. By identifying which patients are at risk and when attrition occurs, we aim to develop a toolkit to improve follow-up rates and, in turn, patient outcomes. Ultimately, the findings will inform future clinical practices and research methodologies, contributing to more representative and robust evidence in hand/wrist trauma management. PROSPERO CRD42024588638.

Pediatric Resuscitation Supply Cabinet Organization: A Systematic Approach.

ABSTRACTThis study examined the effects of caffeine consumption on endurance exercise performance, and the influence of CYP1A2 gene polymorphisms in caffeine pharmacokinetics and exercise performance. The data sets of two randomised, double blind, placebo‐controlled crossover study design experiments have been merged. Thirty‐eight recreationally active male participants provided saliva samples for CYP1A2 genotyping (AA homozygotes n = 19; AC heterozygotes n = 19) and completed either a 10‐km run or 40‐km cycling time trial of 60‐min following a single dose of 6 mg·kg−1 caffeine (CAF) or placebo (maltodextrin; PLA) throughout which heart rate (HR) and time to completion (TTC) were measured. Caffeine ingestion improved TTC by 1.8% (p = 0.05; ηp2 = 0.12). HR was higher in CAF trials compared to PLA (p = 0.02; ηp2 = 0.15). Plasma caffeine concentrations were higher in AA allele carriers compared with AC allele carriers (p = 0.04; ηp2 = 0.139). No caffeine–gene interaction effects were observed in TTC, HR or plasma concentrations of paraxanthine and theophylline. Total caffeine plasma concentrations in the area under the concentration–time curve (AUC) were significantly higher in AA allele carriers compared with AC allele carriers (p = 0.01). Ingesting a dose of 6 mg·kg−1 caffeine 60‐min prior to exercise is likely to improve performance in endurance activities in recreationally trained males. Plasma caffeine concentrations were significantly higher in AA allele carriers compared to AC allele carriers, though no gene–caffeine interaction main effects were observed in TTC; so, the role of CYP1A2 gene polymorphisms in determining enhancements in exercise performance remains unclear.

Kıyıcı, F, Ulupınar, S, Gençoğlu, C, Atasever, G, Seren, K, Çiydem, Ç, and Özbay, S. Physiologic responses and energy system contributions in competitive short track speed skating across race distances. J Strength Cond Res XX(X): 000-000, 2026-This study aimed to quantify and compare the physiologic responses and energy system contributions across 3 standard race distances in elite short track speed skaters. Nine national-level elite male short track speed skaters performed maximal-effort time trials for 500, 1000, and 1,500 m, in randomized order and with full recovery between sessions. Oxygen uptake (V̇o2) was continuously measured using a portable gas analyzer, while blood lactate concentration ([BLa]) was sampled at rest and at multiple time points postexercise. Energy contributions from phosphagen, glycolytic, and aerobic pathways were calculated using validated equations based on V̇o2, EPOC kinetics, and [BLa]. Total energy expenditure increased with distance (500 m: 123.8 ± 16.5 kJ; 1,000 m: 163.1 ± 19.2 kJ; 1,500 m: 201.9 ± 19.6 kJ). Aerobic energy rose significantly from 27.2 ± 2.4 kJ at 500 m to 57.3 ± 4.9 kJ at 1,000 m and 89.1 ± 7.9 kJ at 1,500 m. Glycolytic energy was 50.6 ± 11.5 kJ at 500 m and 55.4 ± 10.6 kJ at 1,000 m, and increased to 60.3 ± 11.5 kJ at 1,500 m. Phosphagen energy also increased with distance (45.7 ± 9.4 kJ; 50.3 ± 10.3 kJ; 52.8 ± 11.2 kJ). In relative terms, aerobic contribution rose from 22.2% at 500 m to 35.3% at 1,000 m and 44.3% at 1,500 m, whereas glycolytic contribution declined from 40.9 to 33.9% and 29.8%, and phosphagen contribution from 36.9 to 30.8% and 26% (all p < 0.05). The findings demonstrate a clear shift from anaerobic to aerobic dominance as race distance increases in short track speed skating. The PCr-La-O2 approach offers detailed insights into metabolic demands across competition distances, supporting tailored training and recovery strategies. The observed nonlinear patterns in glycolytic and phosphagen contributions highlight the importance of distance-specific conditioning in elite speed skating performance.

This study aimed to evaluate the effects of caffeinated chewing gum on 50-m freestyle swimming performance, as well as on pre- and post-performance measures of maximal isometric shoulder flexion strength and blood lactate concentration in male swimmers. In a randomized, double-blind, crossover, placebo-controlled design, ten male swimmers (mean ± SD; age 27 ± 10 years; body mass 82.7 ± 13.6kg; height 179 ± 6cm; body fat 11.9 ± 7.3%) completed two experimental trials. Participants ingested either caffeinated (300mg) or placebo chewing gum followed by a 10-minute absorption period. Swimmers then performed a 50-m freestyle time trial in a pool. Maximal isometric shoulder flexion strength and blood lactate concentrations were measured before and after the swim. Compared to the placebo, caffeinated gum reduced the 50-m swim time from 28.70 ± 1.21 to 28.18 ± 1.31s, resulting in a performance improvement of -1.83% [95% confidence interval: -2.69%, -0.63%] (p = 0.013). However, there were no significant effects of caffeine supplementation on maximal strength (p = 0.261) or blood lactate levels (p = 0.586), nor significant interactions between supplementation and time. Ingesting caffeinated chewing gum just 10min prior to exercise led to a significant enhancement (-1.83%) in 50-m freestyle swimming performance time, independent of changes in maximal shoulder flexion strength or blood lactate concentrations. This suggests that rapid caffeine absorption can benefit sprint swimming performance without affecting muscle strength or lactate metabolism in male swimmers. Brazilian Clinical Trial Registry (https://ensaiosclinicos.gov.br: RBR-3GX2H7F). Registered on October 1, 2025, retrospectively registered.

Strength and power are critical to the successful completion of military duties and missions. Although males are generally stronger and more powerful than females, females better resist fatigue during endurance-based activities. Maintenance of strength and power is also critical to prevent and recover from slip, trip, fall events, which are the top cause of acute non-combat injury in the military. It is not known if military activities, such as ruck marching, differentially affect strength and power between the sexes. The purpose of this study was to compare the effect of unloaded and loaded treadmill walking on strength and power between sexes. Ten males (23 ± 3 years; 74.3 ± 12.8 kg; 173 ± 6 cm; 49.8 ± 4.8 mL·kg-1·min-1) and 10 females (25 ± 4 years; 66.1 ± 10.1 kg; 162 ± 6 cm; 40.4 ± 2.4 mL·kg-1·min-1) completed two 4.8 km time trial walks, once while unloaded and once loaded with 30% of their body mass in a military rucksack. Before and after the walks, subjects completed a 3-repetition maximum deadlift and vertical jump to assess strength and power, respectively. At baseline, males deadlifted more than females before both the unloaded (UNL, 112.3 ± 23.4 kg, 67.7 ± 19.5 kg, P < .01) and loaded trials (LD, 110.9 ± 29.2 kg, 69.1 ± 19.9 kg, P < .01). Males had a higher vertical jump before both trials compared to females (UNL: 47.8 ± 6.2 cm, 37.2 ± 5.9 cm, P < .01; LD: 48.6 ± 6.0 cm, 37.4 ± 6.0 cm, P < .01). There were no differences within sex between the unloaded and loaded trials at baseline for strength (M: P = .64, F: P = .30) or vertical jump height (M: P = .51, F: P = .68). Greater decreases in strength occurred in the loaded trial compared to the unloaded trial (P = .02). This was driven by greater decrease in the loaded trial in females compared to the unloaded trial (P < .01), whereas no differences between the loaded and unloaded trials occurred in males (P = .81). The change in strength did not differ between sexes (P = .12). To assess power, the change in vertical jump height did not differ between the loaded and unloaded trials (P = .17), nor between sexes (P = .86). A loaded time trial walk resulted in greater decrements in strength than an unloaded time trial walk, which was driven by greater decreases in females. However, loaded and unloaded time trial walks resulted in similar changes in power between sexes. Future work is needed to determine whether other multi-joint dynamic strength assessments result in similar decreases after loaded walking and the implications on military populations. This project is registered at clinicaltrials.gov; identifier: NCT05309603.

The ingestion of fructose with glucose has been shown to enhance exogenous carbohydrate oxidation during exercise at sea level compared with glucose alone. Whether this synergistic effect occurs at altitude is yet to be established. This study compared glucose-fructose co-ingestion with the ingestion of glucose alone on fuel use and running performance at 2500m. Ingestion of 1.2gmin-1 glucose plus 0.8gmin-1 fructose (GLU-FRU) was compared with 1.2gmin-1 glucose (GLU) and a placebo during 120min running at 70% performed by eight males at 2500m altitude. Exogenous (individual and combined contributions from fructose and glucose) and endogenous oxidation were quantified using indirect calorimetry and 13C stable mass isotope tracing techniques. Performance was measured using a 5km treadmill time trial. Total cholesterol (CHO) oxidation for the 120min of running was significantly higher for GLU compared with placebo, whereas fat oxidation was no different between conditions. GLU-FRU led to significantly greater exogenous CHO oxidation and lower endogenous CHO oxidation compared with GLU. Time to complete the 5km run was significantly faster in GLU and GLU-FRU compared with placebo, but there were no differences between GLU and GLU-FRU. In conclusion, the co-ingestion of GLU-FRU at altitude increased exogenous and spared endogenous carbohydrate oxidation over glucose alone, as seen at sea level. However, this did not provide a performance benefit for GLU-FRU. Therefore, this is the first demonstration of the synergistic effect of the co-ingestion of GLU-FRU on exogenous CHO oxidation during running at altitude. KEY POINTS: This study is the first to compare glucose alone with glucose-fructose co-ingestion during prolonged running at moderate altitude (2500m). Combining glucose and fructose significantly increases exogenous carbohydrate oxidation and reduces reliance on internal (endogenous) carbohydrate stores compared with glucose alone. Despite improved fuel use, performance in a 5km run was not better with glucose-fructose compared with glucose alone at moderate altitude (2500m), though both were faster than placebo. These findings support glucose-fructose supplementation as an effective strategy to decrease reliance on endogenous carbohydrate stores compared with glucose alone for endurance athletes training or competing at moderate altitude.

ABSTRACTThis study introduces a multi‐timescale mechanical model to quantify proximity to performance limits during endurance exercise. The model represents power output using a set of rolling averages, each associated with a characteristic time constant, and identifies the dominant component as the one approaching its historical maximum at any given time. To demonstrate this framework, real‐world data were collected from 21 male professional cyclists during an 11‐day training camp. Data from the first 10 days were used to construct individual maximal mean power (MMP) profiles across multiple time scales. On the final day, cyclists completed a fatiguing protocol (∼2000 kJ of work) followed by 3‐min and 12‐min maximal time trials. During exercise, the ratio between each exponentially weighted component and its corresponding historical maximum was computed, and the maximum ratio was used to track proximity to performance limits. At the end of the time trials, this ratio reached 98.6% (94.3%–101%) and 101% (98.5%–103%) for the 3‐min and 12‐min efforts, respectively (median and interquartile range), indicating convergence toward maximal performance capacity. Notably, in both trials the dominant component corresponded to a slower time scale (∼1 h), rather than to components matching the nominal duration of the efforts. These findings suggest that performance limits emerge from the interaction of multiple time scales and are not solely dictated by the duration or intensity of the task. This framework extends the traditional use of MMP from a post hoc descriptive tool to a real‐time dynamical measure of performance capacity.

The shorter rowing course at the Los Angeles 2028 Olympics, which is 1500m instead of 2000m, potentially alters the physiological demands of racing. This study aims to elucidate whether the shortened distance favours rowers with a more speed-oriented phenotype, using two non-invasive profiling approaches: locomotor profiling and force-velocity (F-v) profiling. Nine nationally competitive male rowers completed 2000m and 1500m rowing ergometer time trials. Peak power tests and graded exercise tests were used to determine the athletes' locomotor profiles expressed as Power Reserve Ratio (PRR) and loaded back squat testing was performed to establish individual F-v profiles. Relative performance was expressed as the ratio between mean power output of the 1500m and 2000m time trials (MPOratio). PRR showed a strong positive correlation with MPOratio (r = 0.61), indicating that athletes with a more speed-oriented locomotor profile performed relatively better over the shorter distance. F-v slope demonstrated a moderate positive correlation with MPOratio (r = 0.36), which became very strong after excluding an outlier (r = 0.88). Together, these findings support the notion that the shortened Olympic rowing distance places greater emphasis on speed -ability, a challenge that suits athletes leaning towards a more speed-oriented phenotype. While aerobic capacity remains essential in 1500m rowing, subtle adjustments in athlete selection and training toward increased anaerobic and explosive qualities may optimize performance at the Los Angeles 2028 Olympics.

This study investigated cerebral and neuromuscular responses to three exercise models: time trial (TT), maximal oxygen uptake ( ) and time to exhaustion (TTE). Fourteen participants completed the tests in the following order: , TT and TTE. To compare responses across different intensities, TT and trials were matched for total work (kJ), and the average TT power output was used to set intensity for TTE. Throughout exercise, near-infrared spectroscopy from the prefrontal cortex and electromyography from the vastus lateralis and rectus femoris were recorded. Ratings of perceived exertion and the feeling scale were collected post-exercise. Total work was similar across trials. Tissue oxygenation index (TOI) was significantly lower during TT (P=0.0308) and TTE (P=0.0400) than . Deoxyhaemoglobin increased more during TTE (P<0.0001), and oxyhaemoglobin was higher during TTE from 60% to 100% of test completion (P=0.0040-0.0001). Participants rated as more pleasant (6.7±2.9) than TT (5.9±3.0, P=0.0412) and TTE (4.9±2.3; P=0.0124). Despite equivalent work, each exercise model elicited distinct neurophysiological profiles and distinct temporal patterns of prefrontal oxygenation and muscle activation. TT and TTE showed earlier reductions in TOI than , but end-exercise brain oxygenation was similarly reduced across paradigms, while was perceived as more pleasant. These findings suggest that exercise modality alters the trajectory, rather than the endpoint, of prefrontal oxygenation/perfusion responses.

The 800-m track event represents a metabolic paradox in which runners must optimize the depletion rate of finite anaerobic work capacity, W', while avoiding premature estimated metabolic threshold onset. Traditional lactate monitoring suffers from temporal lag, creating a "metabolic black box" that prevents real-time tactical adjustments. This study investigated whether real-time bioenergetic digital twin technology could predict W' depletion trajectories and optimize cadence strategies in elite 800-m runners under competitive metabolic constraints. Twelve elite collegiate 800-m runners completed three experimental trials: laboratory W' quantification via a 3-minute all-out test, an instrumented 800-m time trial with multi-modal biosensing, and an RBDT-guided race simulation. A physiological model-based neural network integrated real-time muscle oxygenation, cadence, and velocity data to estimate instantaneous W' expenditure. The primary outcome was the correlation between predicted and observed performance collapse points, defined operationally as velocity decrement greater than 5%. The RBDT model achieved high predictive accuracy for W' depletion dynamics, with R² = 0.92 and RMSE = 2.88%. Athletes following RBDT-guided cadence adjustments at the critical 500-m node demonstrated 3.2% faster finishing times compared with self-paced trials, with delayed estimated metabolic threshold onset. SHAP analysis showed that feature importance was not static across the race: velocity and acceleration dominated early prediction, SmO₂-derived metrics became most influential during the 400-600m tactical decision phase, and cadence-related variables increased in importance during the terminal 600-800m phase. Real-time metabolic monitoring via RBDT may support precision pacing strategies that maximize W' utilization while reducing premature performance collapse. The results support a transition from experience-based to data-informed tactical decision-making in middle-distance running. However, findings should be interpreted in light of the small sample size, instrumented time-trial setting, and possible psychological effects of audio feedback.