Introduction. The present study had a twofold purpose: to characterize the physiological lactate response and to compare two protocols for determining the anaerobic threshold in university karate athletes from Barranquilla, Colombia. Objective. To characterize the physiological lactate response and to compare two protocols for determining the anaerobic threshold in university karate athletes from Barranquilla, Colombia. Methods. The sample consisted of thirteen athletes (eight men and five women; age: 21.7 ± 2.3 years; BMI: 22.5 ± 1.8kg/m2, who performed a specific incremental kick test (IT) and a lactate minimum test (LMT) in randomized order. During both protocols, capillary blood lactate concentrations, heart rate, and the number of kicks per minute were monitored. The lactate threshold was identified through the consensus of two expert evaluators. Results. Results showed similar lactate values at the threshold for both tests IT: 4.2 ± 0.9 mmol. L-1; LMT: 4.5 ± 1.0 mmol.L-1; p = 0.31; d = 0.19, as well as a high and consistent heart rate response IT: $176 ± 8; LMT: 178 ± 9; p = 0.27; d = 0.23. However, a significant difference was observed in technical performance: the number of kicks at the threshold was higher in the LMT 32 ± 6 vs. 28 ± 5 kicks per minute; p = 0.02; d = 0.72. Bland–Altman analysis revealed a low mean bias -(−0.3 mmol·L⁻¹) and high inter-rater agreement (ICC = 0.91). Conclusions. It is concluded that while both protocols estimate the lactate threshold comparably, the LMT offers greater technical specificity, positioning it as a valuable tool for training planning in the collegiate setting.

Complex network modeling has been applied in sports science research; yet few studies have applied it to capture the dynamic evolution of multivariate relationships within a single session of high-intensity training. This study is the first to use complex network modeling to examine the dynamic associations among kinematic (stroke rate, stroke length), metabolic (blood lactate), and perceived exertion (Rating of Perceived Exertion, RPE) variables and 100-meter freestyle performance. The analysis was conducted on 16 adolescent swimmers during a 6 × 50-meter sprint interval training (6 × 50m SSIT) protocol. The findings showed that the overall network topology remained stable throughout the SSIT protocol, suggesting that multiple training bouts within the session collectively contributed to enhancing 100-meter freestyle performance (network density: from 42.65% to 49.17%; modularity: from 0.2 to 0.24). Nevertheless, the relative importance of individual variables shifted markedly during the training process. Specifically, the nodal centrality of swimming velocity, blood lactate, and RPE increased substantially, positioning them as central hubs mediating performance outcomes. In contrast, the influence of stroke rate progressively declined, whereas stroke length remained relatively stable. This research introduces a powerful analytical tool for the dynamic assessment of training processes and provides valuable insights into the adaptive mechanisms shaping sport-specific anaerobic capacity in competitive swimmers.

Abstract Construction 5.0 advocates human–machine collaboration. Therefore, understanding the human response is crucial for design and scaling up these processes. To date, however, there is no agreed set of methodologies, which would allow quantifying the human effort in the setting of digital construction, nor allow for comparison with traditional construction processes. To close this gap, the current paper presents an experimental consideration of the physiological, biomechanical, and subjective response of human actors, conjoint with productivity of collaborative digital fabrication during Shotcrete 3D Printing (SC3DP), and compares it against the traditional cast reinforced concrete element execution. Several parameters were measured simultaneously during each of the two production processes to quantify the psychophysiological relief experienced by workers. In the SC3DP collaborative process, the following mean values were observed relative to the manual cast concrete process: carried weight – 44%, covered distance – 37%, uncomfortable spine position – 60%, perceived exertion, and demands on the Borg and Nasa Task Load Index (TLX) scales – 63%. Meanwhile, NASA-TLX perceived performance increased by 21%, accompanied by an almost threefold rise in the measured task-level productivity. Interestingly, objective physiological indicators, i.e., heart rate and blood lactate concentration, remained unchanged between the two processes. Another important finding is the high mental demand of the operator of the robotic system. Finally, this paper underlines the need for further development of methods for measuring and assessing construction workers’ psychophysical state, which should be regarded among the key productivity factors, supporting the introduction of digital construction methods in accordance with Industry 5.0 principles.

Purpose This study aimed to investigate the acute responses induced by a session of repeated-sprint training in hypoxia (RSH) induced by voluntary hypoventilation at low lung volume (VHL) performed continuously throughout the exercise in healthy females. Methods Thirteen females performed, in a randomized order, two sessions of repeated sprints (three sets of eight 10-s all-out sprints): with normal breathing (RSN) vs. with VHL performed continuously throughout each set (RSH-VHL). Peak and mean power output, heart rate, stroke volume, cardiac output, pulse oxygen saturation, muscle oxygenation in the vastus lateralis and the biceps brachii, blood lactate concentration, rate of perceived exertion and perceived difficulty of breathing and pedalling were assessed. Results RSH-VHL did not induce desaturation (97.5 ± 2.0 for RSH-VHL vs. 98.0% ± 1.6% for RSN; p = 0.243) nor greater muscle deoxygenation in the vastus lateralis (mean minimum tissue saturation index: 62.3% ± 4.3% vs. 61.5% ± 4.4%; p = 0.193) or the short head of the biceps (36.6% ± 10.0% vs. 34.2% ± 13.7%; p = 0.320). Significantly lower training load indices were observed from the first set onwards during RSH-VHL compared with RSN: mean peak power output (311 ± 45 vs. 382 ± 46 W; p < 0.001) and blood lactate concentration (6.8 ± 2.9 vs. 9.9 ± 3.0 mmol/L; p = 0.003). The perceived difficulty of breathing was higher during RSH-VHL than RSN from the first set onwards (8.2 ± 2.2 vs. 6.0 ± 0.9; p = 0.022). Conclusion This study showed that, although participants reported increased breathing difficulty during RSH-VHL performed continuously, this condition did not result in significant systemic or local hypoxia. Moreover, it led to a lower training load compared to RSN. When VHL is performed continuously throughout each set, rather than only during sprints, it may be too strenuous, inducing a significant reduction in training load.

Background In this study, we sought to investigate the clinical manifestations, laboratory findings and radiographic features of severe Chlamydia psittaci pneumonia requiring invasive mechanical ventilation in the intensive care unit (ICU), as well as evaluate the role of fluoroquinolones in its treatment. Methods We retrospectively reviewed the clinical data of 14 patients diagnosed with severe C. psittaci pneumonia at Zhejiang University School of Medicine, Sir Run Run Shaw Hospital from December 2018 to November 2022. We collected the clinical characteristics, laboratory examination results, imaging features, treatment and prognosis. We used the SPSS 26.0 software to perform statistical analysis. Results Most patients presented high fever (≥39 °C), shortness of breath and cough, as well as extrapulmonary symptoms such as fatigue, dizziness, muscle pain and headache. There were also significant increases in white blood cells, C-reactive protein (CRP), procalcitonin (PCT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and D-dimer, while lymphocytes decreased significantly. Primary chest imaging features included consolidation, exudation and pleural effusion. All 14 patients received fluoroquinolones-based treatment and recovered. Conclusion The clinical manifestations of severe C. psittaci pneumonia are nonspecific. Fluoroquinolones-based treatment may be effective in severe C. psittaci pneumonia with invasive mechanical ventilation in ICU. For severe cases of C. psittaci pneumonia, the treatment regimen may require an intravenous fluoroquinolone-based approach.

We investigated whether an active protocol of ischemic preconditioning (IPC-A) would improve high-intensity intermittent exercise performance in youth team sport players. Fifteen male amateur team sport players (15.5 ± 0.5 yrs) attended four different preconditioning sessions before the YoYo Intermittent Recovery Test level 1 (YYIR1) interspersed by seven days in a counterbalanced randomized cross-over design. IPC protocol consisted of three cycles of 5min occlusion (220 mmHg) and 5min reperfusion (0 mmHg) in both thighs. SHAM was similar to the IPC protocol, but 'occlusion' pressure was set up at 20 mmHg. Active protocols (IPC-A/ SHAM-A) were similar to the IPC/SHAM, but participants exercised (intermittent run) during the 'reperfusion' phases instead of resting. Six minutes after the protocol, the participants performed the YYIR1. The distance covered in the YYIR1 did not differ (p = 0.46) among the protocols: IPC (917 ± 204m) vs. IPC-A (931 ± 211m) vs. SHAM (968 ± 201m) vs. SHAM-A (933 ± 204m). Blood lactate concentration, and mean heart rate did not differ either (p > 0.05) among the protocols. Active ischemic preconditioning involving exercise during reperfusion phase does not improve high-intensity intermittent exercise performance nor alter physiological or perceptual responses in youth team sport players.

Rationale: Exercise intensity is often prescribed as a percentage of a "maximum" reference point. Both the choice of reference and the protocol to obtain it may bias apparent female-male differences in relative intensity. Objective: To examine whether female-male differences in relative intensity expressed relative to a maximum reference (⩒O₂max or PPO) differ depending on the protocol used to determine it (ramp vs. step). Methods: Fifty trained cyclists (30 males, 20 females, 31±8 years old, ⩒O₂max 3866±840ml/min) completed a ramp-incremental and a 3-min step test on a cycle ergometer. Thresholds were determined from fixed and individualized blood lactate concentrations and from ventilation. Relative intensity was expressed in relation to PPO and ⩒O₂max derived from each protocol. Linear mixed-effects models with participant as random intercept tested the fixed effects of Sex, Protocol, and their interaction. Agreement between ramp- and step-derived ⩒O₂max values was evaluated using Bland-Altman analysis. Results:. For ⩒O₂-based relative intensity, only protocol effects were small but significant (all p<0.01). For Power, Sex had a significant influence in the models with males displaying higher relative intensities in all lactate-based thresholds (all p≤0.02). Sex × Protocol interactions emerged for BLa2 and BLamin+0.5(both p<0.05), indicating that using step or ramp protocols as reference can alter the magnitude or direction of female-male differences. Conclusions: Apparent sex differences in relative intensity depend on how "maximum" is defined and obtained. The same relative intensity does not ensure equivalent physiological strain across sexes.

This study examined physiological recovery between repeated tennis drills in elite adolescent tennis players. Ten tennis players (5 males, 5 females; age 17 ± 2 years) underwent treadmill testing to establish maximal physiological characteristics. Several days later participants completed three standardized on-court tennis drills with fixed rest intervals, during which physiological parameters were monitored. A one-way repeated-measures ANOVA was used to compare physiological responses across the three drills. utilization stayed above 75% in all drills, peaking during the first drill (p = 0.003). During recovery, utilization decreased from 58 ± 8% in the first recovery to 50 ± 9% (p = 0.018) and 47 ± 12% (p = 0.022) in the second and third recovery, respectively. The respiratory exchange ratio (RER) stayed below 1.0 during drills, while increasing during recovery periods, (1.07 ± 0.08, 1.00 ± 0.01, 1.04 ± 0.05; p = 0.014). Ventilatory equivalents for oxygen () were stable (p = 0.054), while those for carbon dioxide () increased progressively for each recovery period (29.5 ± 3.6, 31.5 ± 3.8, 32.3 ± 4.3; p < 0.001). Blood lactate concentration differed significantly across recovery periods (p = 0.035) with the lowest value in recovery period two (5.9 ± 2.0, 4.9 ± 1.9 and 5.6 ± 2.0 mmol·l-1). These findings highlight a sustained metabolic demand extending into the recovery phase during standardized tennis drills, characterized by substantial utilization and elevated respiratory compensation. This suggests a significant anaerobic contribution and underscores the intensity of the physiological load imposed even after exercise cessation.

BackgroundCerebral hypometabolism is a hallmark of Alzheimer's Disease (AD) and it is possible that alternative fuel substrates such as lactate could be beneficial in AD. However, how efficiently lactate is metabolized in AD individuals compared to cognitively healthy (CH) older adults has never been characterized.MethodsCH (n = 12) and AD (n = 12) older adults were enrolled into the Lactate for Energy and Neurocognition (LEAN) trial at the KU ADRC (NCT05207397). Subjects underwent a single study visit “lactate clamp”, where they received stable infusions of D2‐glucose, [3‐13C] sodium lactate, and a variable infusion of unlabeled sodium lactate for 120 minutes to achieve 4mM blood lactate. Cognitive tests (NIH toolbox) were administered prior to infusion and at minute 90, during steady state. Breath and blood sampling were performed at 0, 60, 75, 90, and 120 minutes to calculate lactate metabolism. AD blood biomarkers were assessed at 0 and 120 minutes in EDTA plasma. Brain‐derived tau (BD‐tau), pTau217, pTau181, total tau, glial fibrillary acidic protein (GFAP), neurofilament light‐chain (NfL), and Brain Derived Neurotrophic Factor (BDNF) were analyzed by Simoa‐HDX (Quanterix). β‐amyloid 42 and 40 were analyzed using Lumipulse (Fujirebio). We measured creatinine (RayBiotech) and hematocrit (Immunostics, Inc) to assess change in kidney function and blood volume.ResultsAD subjects oxidized lactate as well as CH subjects (p = 0.988). Processing speed (p <0.001) and global cognition (p <0.001) were improved after infusion. Interestingly, we observed reductions in plasma BD‐tau (p <0.001), pTau217 (p <0.001), pTau181 (p <0.001), GFAP (p <0.001), and NfL (p <0.001) in both AD and CH groups after lactate infusion. Total tau and BDNF levels were unchanged by infusion (p = 0.133 and 0.182). Pre/post change in plasma volume and eGFR were 4% and 16.9%, respectively.ConclusionOur objective was to characterize whole‐body lactate metabolism in AD, an understand how lactate might affect cognition. We found that lactate infusion reduced BD‐tau, phosphotau species, GFAP, and NfL which could be due to systemic or brain‐based changes in proteostasis. Biomarker changes were not explained by change in plasma volume or kidney function, and only brain‐specific biomarkers were affected. Additional analyses are planned to investigate the relationship of lactate and perturbations in AD biomarkers.

We investigated the acute physiological responses to circuit strength training performed with different work-to-rest interval durations (10:10, 20:20, and 30:30s) under a constant 1:1 ratio. Thirty-four trained adults (15 males and 19 females) completed a 14-min circuit protocol consisting of two blocks of 6-min separated by a 2-min rest period. Each session included six alternating upper- and lower-body exercises performed at maximal intended velocity. Heart rate (HR) was continuously monitored during the protocol, while blood lactate concentration, countermovement jump (CMJ) height, and 10-m sprint performance were assessed pre-, mid-, and post-circuit session. Repeated-measures ANOVA was used for CMJ height, blood lactate concentration and 10-m sprint performance, and one-way ANOVA for HR data. The 30:30 protocol elicited the highest post-exercise lactate concentrations (p < 0.05) and the largest decrements in CMJ height. In contrast, HR was consistently higher in the 10:10 protocol across several time points (p < 0.01), indicating greater cardiovascular demand. Sprint performance declined from pre- to post-exercise across all protocols, indicating a time-dependent fatigue response. These findings demonstrate that manipulating absolute work-to-rest durations, even under a fixed 1:1 ratio, produces distinct physiological responses, while performance decrements may occur independently of protocol configuration. Longer intervals (30:30) maximize metabolic stress and neuromuscular fatigue, whereas shorter intervals (10:10) enhance cardiovascular load. The 20:20 protocol represents a balanced alternative between both stimuli.

Vascular smooth muscle cells (VSMCs) undergo phenotypic changes during the development of aortic aneurysm and dissection (AAD). Metabolism shifts from oxidative phosphorylation to glycolysis. Recent studies suggest that epigenetics plays a crucial role in AAD. The epigenetic regulation of histone lactylation was analyzed in the aorta of patients with aortic aneurysm and in a murine model of AAD. Histone lactylation was also studied in VSMCs treated with angiotensin II. The epigenetic pathway involving H4K16 lactylation (H4K16la) was explored in vitro and in vivo. To examine the role of H4K16la in AAD formation, mice lacking Pdk1 or Kat7 in VSMCs were created. Mice were treated with pharmacological inhibitors of Pdk1 or Kat7. The levels of blood lactate, aortic lactate, and aortic H4K16la were compared between patients with aortic aneurysm and controls. Histone lactylation (H4K16la) was increased in the aortic tissues of patients with AAD and mice. Enhanced histone lactylation was linked to increased pyruvate dehydrogenase kinase 1 (PDK1) transcription, which accelerated lactate production in VSMCs. A positive feedback loop was identified involving H4K16la, PDK1, and lactate; this pathway alters the metabolism and phenotype of VSMCs. KAT7 (lysine acetyltransferase 7) was found to be a histone lactyltransferase for histone lactylation in VSMCs. Genetic or pharmacological inhibition of PDK1 or KAT7 decreased AAD injury by disrupting the H4K16la/PDK1/lactate pathway. Patients with AAD have elevated lactate in blood and aortic tissues and elevated H4K16la in aortic tissues compared with control patients. Histone lactylation changes the metabolism and phenotype of VSMC in AAD. Inhibition of PDK1 or KAT7 may be a novel approach to treat or prevent AAD.

This study designs and validates a wireless sensor network (WSN) system for the objective, continuous quantification of training intensity in track and field. The system integrates wearable inertial and heart rate sensors, transmitting data via a low-power LoRa (Long Range) network to a cloud platform. Machine learning algorithms classify activities and compute intensity metrics like PlayerLoad™ and Training Impulse (TRIMP). In a 12-week study with 45 university athletes, the system’s intensity metrics show a strong correlation with blood lactate levels (r = 0.92, p &lt; 0.01). The experimental group using the system demonstrates a 15.3% greater improvement in performance times and a 28% reduction in non-functional overreaching compared to the control group, confirming the system’s effectiveness for data-driven training optimization.

This study aimed to explore the relationship between hemodynamic parameters and 28-day survival in patients with sepsis and to evaluate their prognostic value. This retrospective observational study included 165 patients with sepsis admitted to the ICU of our hospital between March 2021 and March 2024. Patients were categorized into survival (n = 126) and non-survival groups (n = 39) based on 28-day outcomes. Hemodynamic assessments within 24 hours of ICU admission included sequential organ failure assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, mean arterial pressure (MAP), systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), lactate, cardiac output (CO), and dynamic indicators such as stroke volume variation (SVV), pulse pressure variation (PPV), and passive leg raise (PLR)-induced CO change. Logistic regression was applied to identify risk factors, and receiver operating characteristic (ROC) curves were used to assess predictive ability. Compared with survivors, non-survivors had higher SOFA (median 12 vs 8, P < .001) and APACHE II scores (median 26 vs 18, P < .001), higher lactate levels (median 4.1 vs 2.3 mmol/L, P < .001), and lower MAP (72 vs 78 mm Hg, P = .012). Multivariate regression identified SOFA score (OR = 1.27, 95% CI: 1.04-1.55, P = .016), MAP (OR = 0.95, 95% CI: 0.91-0.99, P = .012), lactate (OR = 1.52, 95% CI: 1.11-2.08, P = .009). The combined model showed an AUC of 0.851 (95% CI: 0.811-0.891). Hemodynamic parameters, particularly SOFA score, MAP, lactate, and cardiac function indicators, were significantly associated with 28-day mortality in sepsis patients. These findings suggest that integrating static and dynamic hemodynamic monitoring may support early risk stratification, although further prospective multicenter validation is needed.

Clinical Scenario : Oral contraceptive pills are widely used among women to prevent pregnancies and help control symptoms associated with the menstrual cycle. Female athletes using these contraceptives may be susceptible to lower athletic performance because of the effects of the added hormones. Clinical Question : In elite female athletes, do oral hormonal contraceptives affect performance capacity and the ability to sustain exercise over an extended period without fatigue? Summary of Key Findings : None of the studies found significant changes in fatigue and blood lactate suggesting no effect on endurance performance in oral contraceptives pills users. Clinical Bottom Line : Oral contraceptive pills have little to no impact on female athletic performance. Changes in endurance performance, fatigue, blood lactate, and blood lactate threshold were not significant. Strength of Recommendation : The studies selected demonstrate Level B evidence due to the small sample size, inconsistency, and limited quality of evidence.

Exercise interventions are less effective in generating weight loss in females compared with males suggesting that the menstrual cycle may be important. Fluctuations in ovarian hormones are proposed to alter the appetite-regulatory response to exercise across the menstrual cycle and no study has assessed the response in all distinct hormonal phases. To compare postexercise appetite-regulating parameters after a single bout of moderate-intensity continuous training (MICT) across three distinct menstrual phases. Thirteen females (24 ± 4 y; 24.8 ± 5.4 kg·m -2 ) completed 30 min of MICT running in the follicular phase (FP), ovulatory phase (OP), and luteal phase (LP). Acylated ghrelin, active glucagon-like peptide-1 (GLP-1), plasma glucose, insulin, blood lactate, and appetite perceptions were measured preexercise, 0, 30, 60, and 120 min postexercise. Energy intake was recorded for a 3-d period (day before, of, and after each session). Acylated ghrelin was not different across phases ( P = 0.672, η p2 = 0.032) and only showed a main effect of time ( P = 0.006, η p2 = 0.757) increasing with time. Active GLP-1 was not different across phases ( P = 0.735, η p2 = 0.025) and had a main effect of time ( P < 0.001, η p2 = 0.569) decreasing with time. Appetite perceptions were not different across phases ( P = 0.577, η p2 = 0.045) and exhibited a main effect of time ( P < 0.001, η p2 = 0.786) increasing with time. There was no effect of phase for energy intake ( P = 0.544, η p2 = 0.065). Finally, there were no differences in plasma glucose, insulin, or blood lactate across phases ( P > 0.421, η p2 < 0.070). There were no divergent appetite responses after MICT running across three hormonally distinct phases (mid-FP, OP, mid-LP) of the menstrual cycle in young eumenorrheic females not using oral contraceptives.

In untreated non-diabetic subjects, obesity is accompanied by greater associations of blood viscosity with glucose and oxidative metabolism.

Existing Drosophila exercise models only distinguish between regular and endurance exercise based on behavioral traits and have not yet established an exercise physiology classification system based on metabolic traits, which restricts the depth of application of this model organism in exercise physiology research. This study aims to establish an aerobic/anaerobic metabolic model of Drosophila by constructing an incremental load exercise model. Method: A 7-day-old wild-type Drosophila was used as the study subject for the exercise intervention using a Drosophila exercise device. Six exercise intensity gradients were used in this study: 0.31 rev/s (E1), 0.45 rev/s (E2), 0.59 rev/s (E3), 0.71 rev/s (E4), 0.83 rev/s (E5), and 0.91 rev/s (E6). Drosophila in all exercise groups were subjected to a single acute exercise session of 2.5 h. No exercise intervention was performed in the control group. At the end of the exercise, the expression levels of anaerobic metabolizing enzymes (Hex-A, Hex-C, Pfk, Pyk, Ldh) and aerobic metabolizing enzymes (dPdh-A, dPdh-B, Idh, Nc73EF, whd) in Drosophila were detected by RT-qPCR. Meanwhile, the type of aerobic and anaerobic metabolism during Drosophila exercise was comprehensively analyzed by measuring Drosophila blood lactate concentration, respiratory quotient, mitochondrial function, and alginate concentration. 1) Anaerobic metabolism key enzyme activity showed a peak response at E5 loading intensity, and aerobic metabolism marker enzyme activity reached the activation threshold at E2 intensity; 2) blood lactate kinetic curve showed that the overall concentration was significantly higher than that of the control group (P &lt; 0.05), and a significant inflection point at E5 intensity; 3) a significant increase in the respiratory quotient occurred when the loading intensity was elevated to E5 and E6 (P &lt; 0.01); 4) Trehalose concentration decreased dose-dependently with loading intensity; 5) Mitochondrial maximal respiratory capacity was enhanced with exercise loading, and a significant elevation of E5 intensity occurred (P &lt; 0.05), and E6 intensity entered a plateau; 6) The metabolic effects produced by E5 and E2 loading interventions were homologous to the characteristics of human aerobic/anaerobic exercise benefit. Drosophila showed a dominant anaerobic metabolic phenotype at 0.83 rev/s (E5) loading intensity, while 0.45 rev/s (E2) intensity showed a typical aerobic metabolic pattern.

This study examined the effects of low- and high-pressure ischemic preconditioning (LIPC and HIPC) on muscle oxygenation, physiological responses, and performance during repeated 2000-m rowing trials. This was a counterbalanced, repeated-measures crossover study. Eleven elite high school rowers were randomly assigned to 1 of 3 warm-up protocols: (1) traditional warm-up (control trial [CON]), (2) LIPC (100-190mmHg) + traditional warm-up, or (c) HIPC (210-300mmHg) + traditional warm-up. Measurements were taken beforeand after warm-up, immediately following two 2000-m rowing efforts, and 10minutes postexercise. Variables included blood lactate, heart rate, rating of perceived exertion, muscle tissue oxygen saturation (tissue saturation index), mean power output, and total time. Significantly greater reductions in tissue saturation index of the vastus lateralis during occlusion were observed in LIPC (36.41% [12.03%]) and HIPC (35.05% [14.29%]) compared with CON (10.43% [4.9%], P < .001). No significant group differences were found in blood lactate, heart rate, or rating of perceived exertion, although time effects were noted (P < .001). While first-trial performance was similar, the second 2000-m trial showed significant group differences (P = .009), with HIPC outperforming both CON and LIPC (P < .05). The CON group demonstrated a performance decline, while LIPC and HIPC maintained output. High-pressure ischemic preconditioning also exhibited significantly higher mean power in the second trial compared with CON (P = .04), with consistent pacing. These findings suggest that ischemic preconditioning, particularly HIPC, may enhance repeated high-intensity rowing performance by improving muscle oxygen extraction and sustaining output, offering practical benefits for endurance athletes.

Acclimation to moderate hypoxia improves acute hypoxia tolerance of diploid and triploid brook charr, Salvelinus fontinalis.

Vinovrski, MF, Moll, R, Odebode, JO, Kenny, DA, Allocco, IN, Patel, YM, Schroeder, BG, and Beyer, KS. Physiologic and perceptual responses during resistance exercise with self-selected and nonpreferred music. J Strength Cond Res 40(1): 9-15, 2026-The purpose of this study was to investigate the effects of different music types on physiology, perception, and performance during resistance exercise. Nineteen resistance-trained men (n = 9) and women (n = 10) completed this counterbalanced, crossover study. On visit 1, subjects were assessed for body composition, performed a warm-up, and were estimated for 1 repetition maximum on squat, bench press, deadlift (DL), and bent-over rows. Subjects created a 5-song self-selected music (SSM) playlist and selected their least preferred genre for a nonpreferred (NON) playlist. On 2 subsequent visits, subjects completed 3 sets to failure of each exercise while listening to SSM or NON. Repetitions and rating of perceived exertion were recorded after each set. Blood lactate, focus, energy, fatigue, motivation, and enjoyment were assessed before the warm-up, each exercise, and after the session. Heart rate, muscle activation, ventilation, and muscle oxygenation were measured throughout each workout. Data were analyzed using 3-way analysis of variances with post hoc Bonferroni-adjusted comparisons. A significant trial × exercise interaction (p = 0.016) showed greater repetitions for squat (p = 0.005) and DL (p = 0.011) during SSM than during NON. Significant trial × time interactions for motivation (p < 0.001) and enjoyment (p < 0.001) revealed no significant changes from pre- to postexercise during SSM, but significant decreases during NON. Main effects for focus (p = 0.023) and energy (p = 0.020) favored SSM. No significant effects were noted for heart rate, muscle oxygen, muscle activation, or ventilation. Furthermore, no effects of sex were observed for any variable. Self-selected music during resistance exercise led to more repetitions without increasing exertion or fatigue, with higher reported focus, energy, enjoyment, and motivation.