Exertional rhabdomyolysis among active component members of the U.S. Armed Forces, 2019-2023.

A largely preventable condition, exertional rhabdomyolysis persists as an occupational hazard of military training and operations, especially in high heat environments among individuals exerting themselves to their physical endurance limits. During the 5-year surveillance period of this study, unadjusted incidence rates of exertional rhabdomyolysis per 100,000 person-years among U.S. active component service members fluctuated, reaching a low of 38.0 cases in 2020 and peaking at 40.5 cases in 2023. The rate in 2020 constituted a decline of 3.8% from the rate in 2019 (39.5 cases). Beginning in 2020, incidence rates per 100,000 person-years gradually increased, by 1.8% in 2021 (38.7 cases), 5.3% in 2022 (40.0 cases), and 6.6% in 2023 (40.5 cases). Consistent with prior reports, subgroup-specific crude rates in 2023 were highest among men, those less than 20 years old, non-Hispanic Black service members, Marine Corps or Army members, and those in combat-specific and 'other' occupations. Recruits experienced the highest rates of exertional rhabdomyolysis during each year, with incidence rates 6 to 10 times greater than all other service members.

Exertional hyponatremia among active component members of the U.S. Armed Forces, 2008-2023.

Exertional hyponatremia, or exercise-associated hyponatremia, occurs within 24 hours after physical activity due to a serum, plasma, or blood sodium concentration (Na+) below the normal reference range of 135 mEq/L. If not detected early and managed properly, hyponatremia can be fatal. From 2008 to 2023, 1,812 cases of exertional hyponatremia were diagnosed among U.S. active component service members (ACSMs), with an overall incidence rate of 8.3 cases per 100,000 person-years (p-yrs). In 2023 there were 153 cases of exertional hyponatremia diagnosed among ACSMs, resulting in a crude incidence rate of 11.7 per 100,000 p-yrs. Female service members, those older than 40, non-Hispanic Black service members, Marine Corps members, recruits, those in combat-specific occupations, and ACSMs stationed in the Northeast U.S. region had higher incidence rates of exertional hyponatremia diagnoses than their respective counterparts. During the surveillance period, annual rates of incident exertional hyponatremia diagnoses peaked in 2010 (12.8 per 100,000 p-yrs) and then decreased to a low of 5.3 cases per 100,000 p-yrs in 2013. Thereafter the incidence rate fluctuated but has increased from 6.2 per 100,000 p-yrs in 2017 to its second-highest level in 2023. Service members and their supervisors should be aware of the dangers of excessive fluid consumption and prescribed limits for consumption during prolonged physical activity including field training exercises, personal fitness training, or recreational activities, particularly in hot, humid weather.

Are incremental exercise relationships between rating of perceived exertion and oxygen uptake or heart rate reserve valid during steady-state exercises?

Background: Rating of perceived exertion (RPE) is considered a valid method for prescribing prolonged aerobic steady-state exercise (SSE) intensity due to its association with physiological indicators of exercise intensity, such as oxygen uptake (V̇O2) or heart rate (HR). However, these associations between psychological and physiological indicators of exercise intensity were found during graded exercise tests (GXT) but are currently used to prescribe SSE intensity even though the transferability and validity of the relationships found during GXT to SSE were not investigated. The present study aims to verify whether (a) RPE-HR or RPE-V̇O2 relations found during GXTs are valid during SSEs, and (b) the duration and intensity of SSE affect these relations. Methods: Eight healthy and physically active males (age 22.6 ± 1.2 years) were enrolled. On the first visit, pre-exercise (during 20 min standing) and maximal (during a GXT) HR and V̇O2 values were measured. Then, on separate days, participants performed 4 SSEs on the treadmill by running at 60% and 80% of the HR reserve (HRR) for 15 and 45 min (random order). Individual linear regressions between GXTs' RPE (dependent variable) and HRR and V̇O2 reserve (V̇O2R) values (computed as the difference between maximal and pre-exercise values) were used to predict the RPE associated with %HRR (RPEHRR) and %V̇O2R (RPEV̇O2R) during the SSEs. For each relation (RPE-%HRR and RPE-%V̇O2R), a three-way factorial repeated measures ANOVA (α = 0.05) was used to assess if RPE (dependent variable) was affected by exercise modality (i.e., RPE recorded during SSE [RPESSE] or GXT-predicted), duration (i.e., 15 or 45 min), and intensity (i.e., 60% or 80% of HRR). Results: The differences between RPESSE and GXT-predicted RPE, which were assessed by evaluating the effect of modality and its interactions with SSE intensity and duration, showed no significant differences between RPESSE and RPEHRR. However, when RPESSE was compared with RPEV̇O2R, although modality or its interactions with intensity were not significant, there was a significant (p = 0.020) interaction effect of modality and duration yielding a dissociation between changes of RPESSE and RPEV̇O2R over time. Indeed, RPESSE did not change significantly (p = 0.054) from SSE of 15 min (12.1 ± 2.0) to SSE of 45 min (13.5 ± 2.1), with a mean change of 1.4 ± 1.8, whereas RPEV̇O2R decreased significantly (p = 0.022) from SSE of 15 min (13.7 ± 3.2) to SSE of 45 min (12.4 ± 2.8), with a mean change of -1.3 ± 1.5. Conclusion: The transferability of the individual relationships between RPE and physiological parameters found during GXT to SSE should not be assumed as shown by the results of this study. Therefore, future studies modelling how the exercise prescription method used (e.g., RPE, HR, or V̇O2) and SSE characteristics (e.g., exercise intensity, duration, or modality) affect the relationships between RPE and physiological parameters are warranted.

Every Picture Tells A Story: Managing Exertional Heatstroke with Rotating Ice Water Towels.

ABSTRACT: A 23-year-old woman completing her first marathon collapsed near the finish line at 4 hours 6 min with a rectal temperature of 41.8°C. She was in good health before the race with no recent illness, had completed a full training program, and was taking no medications or supplements. On the initial exam, she was unconscious with a response to painful stimulus, spontaneous breathing, rapid pulse, eyes closed, fully dilated pupils, poor muscle tone, and pale skin that was warm to touch. The medical team initiated whole-body cooling using rapidly rotating ice water towels and ice packs placed in the neck, axilla, and groin. She developed echolalia during active cooling. About 20 minutes into the cooling procedure, she "woke up," was able to answer questions coherently, and her pupils were normal size and reactive. She was discharged home with instructions to follow-up in 2 d for evaluation and blood chemistry testing.

Hematological and physiological responses in polo ponies with different field-play positions during low-goal polo matches.

Strenuous exercise in traditional polo matches creates enormous stress on horses. Hematological and physiological measures may vary across different field-play positions. This study aimed to investigate the effort intensity and the impact of exertion on hematology and heart rate variability (HRV) in polo ponies with different positions. Thirty-two ponies, divided equally into eight teams, were studied. Each comprises forwards (number 1), midfielders (numbers 2 and 3), and defenders (number 4). Team pairs played the first chukka in four low-goal polo matches. Percent maximum heart rate (%HRmax), indicating ponies' effort intensity, was classified into five zones, including zones 1 (<70%), 2 (70-80%), 3 (80-90%), 4 (90-95%) and 5 (>95%). Hematological and HRV parameters were determined before, immediately after, and at 30-minute intervals for 180 minutes after chukkas; HRV variables were also obtained during warm-up and exercise periods. Results indicated that the number two ponies spent more time in zone 4 (p < 0.05) but less in zone 2 (p < 0.01) than the number four ponies. Cortisol levels increased immediately and 30 minutes afterward (p < 0.0001 for both) and then returned to baseline 60-90 minutes after exertion. Other measures (Hct, Hb, RBC, WBC, neutrophils, and CK enzyme) increased immediately (p < 0.0001 for all) and lasted at least 180 minutes after exertion (p < 0.05-0.0001). HRV decreased during the chukka until approximately 90 minutes afterward (p < 0.05-0.0001). The stress index increased during the chukka and declined to baseline at 60 minutes in number 1-3 ponies but lasted 90 minutes in those at number four. Effort intensity distribution differed among field-play positions. Decreased HRV indicated reduced parasympathetic activity during exercise, extending to 90 minutes after exertion in polo ponies. Defenders seem to experience more stress than those in other positions.

The effects of wearing face masks on the perception and mood of male healthy male adults during treadmill running: A pilot study.

In the past few years, the face mask has been recommended for the prevention of exposing others to COVID-19. Wearing a face mask may have the potential to increase dyspnea and discomfort during exercise; however, controversy exists on whether wearing face masks during exercise affects exercise performance, perception, and mood in runners. We investigated the physiological and perceptual responses of healthy male adults who had experienced long-distance running while exercising at different intensities. Nine healthy young adults who were long-distance runners wearing surgical face mask conducted an incremental treadmill protocol. The protocol was three 6-min stages (20%, 40%, and 60% of maximal heart rate, respectively). The rating of perceived exertion (RPE) and the feeling scale (FS) were measured. RPE was higher in mask condition than in unmask condition (No mask vs. Face mask, light; 8.22 vs. 8.78, p = 0.615, middle; 10.00 vs. 10.78, p = 0.345, high; 12.33 vs. 13.67, p = 0.044.), while FS was not different between conditions. The present study shows that wearing a mask may increase rating of perceived exertion and discomfort when the exercise intensity exceeds a certain threshold in healthy male adults who have experienced long-distance running.

The perception of time is slowed in response to exercise, an effect not further compounded by competitors: behavioral implications for exercise and health.

INTRODUCTION: The theory of relativity postulates that time is relative to context and exercise seems such a situation. The purpose of this study was to examine whether situational factors such as perceived exertion and the introduction of an opponent influence competitors' perception of time. METHODS: Thirty-three recreationally active adults (F = 16; M = 17) performed three standardized 4-km cycling trials in a randomized order. Velotron 3D software was used to create a visual, virtual environment representing (1) a solo time trial (FAM and SO), (2) a time trial with a passive opponent avatar (PO), and (3) a time trial with an opponent avatar and participant instruction to actively finish the trial before the opponent (AO). Participants were asked to estimate a 30-s time period using a standardized protocol for reproducibility before exercise at 500 m, 1500 m, 2500 m, and post exercise. Rate of perceived exertion (RPE) was measured throughout the trials. RESULTS: Exercise trials revealed that time was perceived to run "slow" compared to chronological time during exercise compared to resting and post-exercise measurements (p < 0.001). There was no difference between exercise conditions (SO, PO, and AO) or time points (500 m, 1500 m, and 2500 m). RPE increased throughout the trials. CONCLUSION: The results of this study demonstrate for the first time that exercise both with and without the influence of opponents influences time perception. This finding has important implications for healthy exercise choices and also for optimal performance. Independent of RPE, time was perceived to move slower during exercise, underpinning inaccurate pacing and decision-making across physical activities.

ASSESSMENT OF REACTIVITY TO THE BODY UNDER CONDITIONS OF PHYSICAL ACTIVITY IN STUDENTS AGED 17-20 YEARS.

Physical activity is such an essential socio-biological element, which provides a balance between the body and the external environment and contributes to the improvement of metabolic process regulation mechanisms. However, the abuse of physical activity often leads to unwanted changes in the basic physiological processes in the athletes' organism, due to the impact of a variety of reasons. The state of the organism's regulatory systems and the provision of the necessary adaptation of the organism to physical activity are crucial in assessing the athlete's physical fitness. It is known that during physical exertion, the functional state of the organism is determined by a reaction limiting the efficiency of the cardiovascular and respiratory systems. It was revealed that with long-term physical activity restriction, blood circulation regulatory mechanisms, as well as synocardial reflexes, are disrupted. This research is devoted to the study of students' organism adaptive capabilities depending on the central or autonomous type of vegetative regulation. Registration and analysis of ECG of students by the method of variational heart rate monitoring were carried out. With the help of a special program, the students' heart rate integral indicators were analyzed. All studies were carried out twice: before physical exertion and immediately after physical exertion. In this study, we aimed to explore the adaptive capabilities of students bodies depending on the central or autonomous type of autonomic regulation. Three types of response to physical activity have been identified: optimal, paradoxical, and atypical. In all types of reactions, a certain level and direction of intensity of the processes of regulation of the athletes' organism is expressed. The study of the distinctive features of vegetative regulation makes it possible to assess athletes' organism functional state better and determine violations of their adaptive capabilities. According to the research results, based on the primary signs of the athletes' organism adaptive capabilities and the corresponding reaction, it is possible to determine the optimal dose of physical exertion for athletes.

Comparison Between Traditional and Alternated Resistance Exercises on Blood Pressure, Acute Neuromuscular Responses, and Rating of Perceived Exertion in Recreationally Resistance-Trained Men.

ABSTRACT: Corrêa Neto, VG, Silva, DdN, Palma, A, de Oliveira, F, Vingren, JL, Marchetti, PH, da Silva Novaes, J, and Monteiro, ER. Comparison between traditional and alternated resistance exercises on blood pressure, acute neuromuscular responses, and rating of perceived exertion in recreationally resistance-trained men. J Strength Cond Res 38(5): e211-e218, 2024-The purpose of this study was to compare the acute effects of traditional and alternated resistance exercises on acute neuromuscular responses (maximum repetition performance, fatigue index, and volume load), rating of perceived exertion (RPE), and blood pressure (BP) in resistance-trained men. Fifteen recreationally resistance-trained men (age: 26.40 ± 4.15 years; height: 173 ± 5 cm, and total body mass: 78.12 ± 13.06 kg) were recruited and performed all 3 experimental conditions in a randomized order: (a) control (CON), (b) traditional (TRT), and (c) alternated (ART). Both conditions (TRT and ART) consisted of 5 sets of bilateral bench press, articulated bench press, back squat, and Smith back squat exercises at 80% 1RM until concentric muscular failure. The total number of repetitions performed across sets in the bench press followed a similar pattern for TRT and ART, with significant reductions between sets 3, 4, and 5 compared with set 1 (p < 0.05). There was a significant difference for set 4 between conditions with a lower number of repetitions performed in the TRT. The volume load was significantly higher for ART when compared with TRT. TRT showed significant reductions in BP after 10-, 40-, and 60-minute postexercise and when compared with CON after 40- and 60-minute postexercise. However, the effect size illustrated large reductions in systolic BP during recovery in both methods. Thus, it is concluded that both methods reduced postexercise BP.

Performance and perceived fatigability across the intensity spectrum: role of muscle mass during cycling.

The role of muscle mass in modulating performance and perceived fatigability across the entire intensity spectrum during cycling remains unexplored. We hypothesized that at task failure (Tlim), muscle contractile function would decline more following single- (SL) versus double-leg (DL) cycling within severe and extreme intensities, but not moderate and heavy intensities. After DL and SL ramp-incremental tests, on separate days, 11 recreationally active males (V̇o2max: 49.5 ± 7.7 mL·kg-1·min-1) completed SL and DL cycling until Tlim within each intensity domain. Power output for SL trials was set at 60% of the corresponding DL trial. Before and immediately after Tlim, participants performed an isometric maximal voluntary contraction (MVC) coupled with one superimposed and three resting femoral nerve stimulations [100 Hz; 10 Hz; single twitch (Qtw)] to measure performance fatigability. Perceived fatigue, leg pain, dyspnea, and effort were collected during trials. Tlim within each intensity domain was not different between SL and DL (all P > 0.05). MVC declined more for SL versus DL following heavy- (-42 ± 16% vs. -30 ± 18%; P = 0.011) and severe-intensity cycling (-41 ± 12% vs. -31 ± 15%; P = 0.036). Similarly, peak Qtw force declined more for SL following heavy- (-31 ± 12% vs. -22 ± 10%; P = 0.007) and severe-intensity cycling (-49 ± 13% vs. -40 ± 7%; P = 0.048). Except for heavy intensity, voluntary activation reductions were similar between modes. Similarly, except for dyspnea, which was lower for SL versus DL across all domains, ratings of fatigue, pain, and effort were similar at Tlim between exercise modes. Thus, the amount of muscle mass modulates the extent of contractile function impairment in an intensity-dependent manner.NEW & NOTEWORTHY We investigated the modulatory role of muscle mass on performance and perceived fatigability across the entire intensity spectrum. Despite similar time-to-task failure, single-leg cycling resulted in greater impairments in muscle contractile function within the heavy- and severe-intensity domains, but not the moderate- and extreme-intensity domains. Perceived fatigue, pain, and effort were similar between cycling modes. This indicates that the modulatory role of muscle mass on the extent of performance fatigability is intensity domain-dependent.

Self-efficacy, Effort, and Performance Perceptions Enhance Psychological Responses to Strength Training in National Collegiate Athletic Association Division I Athletes.

ABSTRACT: Biscardi, LM, Miller, AD, Andre, MJ, and Stroiney, DA. Self-efficacy, effort, and performance perceptions enhance psychological responses to strength training in National Collegiate Athletic Association Division I athletes. J Strength Cond Res 38(5): 898-905, 2024-This study examined the effect of self-efficacy, effort, and perceived performance on positive well-being (PWB) and psychological distress (PD) following high-intensity resistance training sessions in collegiate student-athletes. An observational field study design was used to collect data before and after resistance training sessions in a 4-week preseason strength training block. A multilevel model assessed day-level and person-level variance in acute PWB and PD. Interaction terms were also tested at the day level. Alpha was set at 0.05. Within a 4-week training block, training session intensity did not predict changes in acute psychological responses. After controlling for an athlete's preexercise psychological state, higher self-efficacy, daily effort, and perceived performance predicted higher PWB and lower PD following training (p < 0.05). Self-efficacy moderated the relationships of daily effort and performance with PD (p < 0.05). When athletes experienced lower self-efficacy, producing a higher effort and perceiving better performance reduced the negative psychological response. These findings highlight the important mediating role of cognitive variables in the acute psychological response to high-intensity resistance training. Coaches should identify and mitigate low cognitive states to facilitate a positive psychological response to resistance training. This strategy promotes a positive psychological response without altering training prescription.

The Effects of Anchoring a Fatiguing Forearm Flexion Task to a High vs. Low Rating of Perceived Exertion on Torque and Neuromuscular Responses.

ABSTRACT: Ortega, DG, Housh, TJ, Smith, RW, Arnett, JE, Neltner, TJ, Schmidt, RJ, and Johnson, GO. The effects of anchoring a fatiguing forearm flexion task to a high versus low rating of perceived exertion on torque and neuromuscular responses. J Strength Cond Res 38(5): e219-e225, 2024-This study examined the torque and neuromuscular responses following sustained, isometric, forearm flexion tasks anchored to 2 ratings of perceived exertion (RPE). Nine men (mean ± SD: age = 21.0 ± 2.4 years; height = 179.5 ± 5.1 cm; body mass = 79.6 ± 11.4 kg) completed maximal voluntary isometric contractions (MVIC) before and after sustained, isometric, forearm flexion tasks to failure anchored to RPE = 2 and RPE = 8. The amplitude (AMP) and mean power frequency (MPF) of the electromyographic (EMG) signal were recorded from the biceps brachii. Normalized torque was divided by normalized EMG AMP to calculate neuromuscular efficiency (NME). A dependent t-test was used to assess the mean difference for time to task failure (TTF). Repeated-measures analysis of variances was used to compare mean differences for MVIC and normalized neuromuscular parameters. There was no significant difference in TTF between RPE = 2 and RPE = 8 (p = 0.713). The MVIC decreased from pretest to posttest at RPE = 2 (p = 0.009) and RPE = 8 (p = 0.003), and posttest MVIC at RPE = 8 was less than that at RPE = 2 (p < 0.001). In addition, NME decreased from pretest to posttest (p = 0.008). There was no change in normalized EMG AMP or EMG MPF (p > 0.05). The current findings indicated that torque responses were intensity specific, but TTF and neuromuscular responses were not. Furthermore, normalized EMG AMP and EMG MPF remained unchanged but NME decreased, likely due to peripheral fatigue and excitation-contraction coupling failure. Thus, this study provides information regarding the neuromuscular responses and mechanisms of fatigue associated with tasks anchored to RPE, which adds to the foundational understanding of the relationship between resistance exercise and the perception of fatigue.

Exploration and Application of a Muscle Fatigue Assessment Model Based on NMF for Multi-Muscle Synergistic Movements.

Muscle fatigue significantly impacts coordination, stability, and speed in daily activities. Accurate assessment of muscle fatigue is vital for effective exercise programs, injury prevention, and sports performance enhancement. Current methods mostly focus on individual muscles and strength evaluation, overlooking overall fatigue in multi-muscle movements. This study introduces a comprehensive muscle fatigue model using non-negative matrix factorization (NMF) weighting. NMF is employed to analyze the duration multi-muscle weight coefficient matrix (DMWCM) during synergistic movements, and four electromyographic (EMG) signal features in time, frequency, and complexity domains are selected. Particle Swarm Optimization (PSO) optimizes feature weights. The DMWCM and weighted features combine to calculate the Comprehensive Muscle Fatigue Index (CMFI) for multi-muscle synergistic movements. Experimental results show that CMFI correlates with perceived exertion (RPE) and Speed Dynamic Score (SDS), confirming its accuracy and real-time tracking in assessing multi-muscle synergistic movements. This model offers a more comprehensive approach to muscle fatigue assessment, with potential benefits for exercise training, injury prevention, and sports medicine.

Greater Psychophysiological Intensities in Conditioned Games May Impair Technical Performance: An Exploratory Study in Youth Male Soccer Players.

PURPOSE: The aim of this study was 2-fold: (1) to examine the relationships between psychophysiological responses and locomotor demands with variations in technical performance during 2v2 and 4v4 conditioned games and (2) to compare psychophysiological and locomotor responses among players exhibiting higher and lower technical performance levels during the conditioned games. METHODS: Twenty-four male youth soccer players (16.3 ± 0.8 y old) participating at the trained/developmental level underwent monitoring for psychophysiological responses (including heart rate, rating of perceived exertion, and visual analog scale), locomotor demands (such as distance covered), and technical performance variables (including successful and unsuccessful passes and shots, as well as lost balls) across 2v2 and 4v4 formats. These formats were applied 4 times within a single session and were replicated twice over 2 weeks. RESULTS: Large correlations between the number of lost balls per minute and mean heart rate were found in both the 2v2 and 4v4 games (r = .586 and r = .665, respectively). Successful shots were inversely and largely correlated with mean heart rate (r = -.518) in 4v4 games. The number of interceptions per minute was inversely and significantly correlated with the visual analog scale in 2v2 and 4v4 games (r = -.455 and r = -.710, respectively). The frequency of lost balls was significantly higher among players who attained a higher mean heart rate (2v2: +42.9%, P = .031, d = -0.965; 4v4: +57.1%, P < .001, d = -2.072). CONCLUSIONS: Coaches should be aware that highly psychophysiologically demanding scenarios may significantly impair technical performance. Therefore, prioritizing technical performance by deliberately adjusting the intensity should be considered.

The effects of sleep deprivation and extreme exertion on cognitive performance at the world-record breaking Suffolk Back Yard Ultra-marathon.

Using a prospective observational design, this study investigated the hypothesis that competing in the Suffolk Back Yard Ultra-marathon, would result in impaired cognitive performance and examined whether pre-race sleep patterns could mitigate this. Fifteen runners (1 female) volunteered to undertake this study and eleven males were included in the final analysis. Before the race and after withdrawal participants completed the following cognitive performance tasks: 2 Choice Reaction Time (2CRT), Stroop, and the Tower Puzzle. Pre-race sleep strategies were subjectively recorded with a 7-day sleep diary. Following race withdrawal, reaction time increased (Δ 77±68 ms; p = 0.004) in the 2CRT and executive function was impaired in the Stroop task (Interference score Δ -4.3±5.6 a.u.; p = 0.028). Decision making was not affected in the Tower Puzzle task. There was a significant correlation between the pre-race 7-day average sleep scores and both 2CRT Δ throughput (r = 0.61; p = 0.045) and 2CRT Δ RT (r = -0.64; p = 0.034). This study supports the hypothesis that running an ultra-marathon, which includes at least one night of sleep deprivation, impairs cognitive performance and provides novel evidence suggesting good sleep quality, in the week prior to an ultra-marathon, could minimise these effects.

The Quantification of Physical Performance and Internal Training Load in Youth Male Soccer Players During Preseason.

PURPOSE: The monitoring of training loads and quantification of physical performance are common practices in youth soccer academies to support coaches in prescribing and programming training for individuals. The interaction between training load and physical performance is unknown during a preseason period in youth soccer players. The current study assessed changes in training load and physical assessments across a 4-week preseason period. The relationship between physical performance and match playing time in youth male soccer players was also investigated. METHODS: The training loads of 25 professional youth academy male soccer players were monitored throughout a 4-week preseason period. Assessments of power, agility, speed, and aerobic capacity were undertaken in the first training session. Session ratings of perceived exertion (sRPE) and well-being questionnaires were collected during all training sessions and preseason matches. Playing time during subsequent competitive matches was recorded. RESULTS: T test and 30-m-sprint assessments, conducted on the first day of preseason, were predictors of sRPE throughout preseason (t test χ2/df = 2.895, poor adjustment; 30-m sprint χ2/df = 1.608, good adjustment). YoYo Test performance was related with changes in perceived fatigue (χ2/df = 0.534, very good adjustment). Faster players reported higher values of sRPE, and players with higher aerobic capacity reported higher levels of fatigue across preseason. Well-being, perceived fatigue and soreness, and sRPE decreased across preseason. Greater match durations were related to higher levels of fatigue during preseason (P < .05). CONCLUSION: The current study highlights the relationship between training load, physical assessments, and playing time. Coaches and practitioners can use physical test data at the start of preseason as an indication of players that report higher sRPE, perceived fatigue, and reduced well-being across preseason, supporting decisions around individualized training prescriptions.

Gehua Jiejiu Dizhi decoction ameliorates alcoholic fatty liver in mice by regulating lipid and bile acid metabolism and with exertion of antioxidant stress based on 4DLabel-free quantitative proteomic study.

OBJECTIVE: To analyze the effect and molecular mechanism of Gehua Jiejiu Dizhi decoction (, GJDD) on alcoholic fatty live disease (AFLD) by using proteomic methods. METHODS: The male C57BL/6J mouse were randomly divided into four groups: control group, model group, GJDD group and resveratrol group. After the AFLD model was successfully prepared by intragastric administration of alcohol once on the basis of the Lieber-DeCarli classical method, the GJDD group and resveratrol group were intragastrically administered with GJDD (4900 mg/kg) and resveratrol (400 mg/kg) respectively, once a day for 9 d. The fat deposition of liver tissue was observed and evaluated by oil red O (ORO) staining. 4DLabel-free quantitative proteome method was used to determine and quantify the protein expression in liver tissue of each experimental group. The differentially expressed proteins were screened according to protein expression differential multiples, and then analyzed by Gene ontology classification and Kyoto Encyclopedia of Genes and Genomes pathway enrichment. Finally, expression validation of the differentially co-expressed proteins from control group, model group and GJDD group were verified by targeted proteomics quantification techniques. RESULTS: In semiquantitative analyses of ORO, all kinds of steatosis (ToS, MaS, and MiS) were evaluated higher in AFLD mice compared to those in GJDD or resveratrol-treated mice. 4DLabel-free proteomics analysis results showed that a total of 4513 proteins were identified, of which 3763 proteins were quantified and 946 differentially expressed proteins were screened. Compared with the control group, 145 proteins were up-regulated and 148 proteins were down-regulated in the liver tissue of model group. In addition, compared with the model group, 92 proteins were up-regulated and 135 proteins were down-regulated in the liver tissue of the GJDD group. 15 differentially co-expressed proteins were found between every two groups (model group vs control group, GJDD group vs model group and GJDD group vs control group), which were involved in many biological processes. Among them, 11 differentially co-expressed key proteins (Aox3, H1-5, Fabp5, Ces3a, Nudt7, Serpinb1a, Fkbp11, Rpl22l1, Keg1, Acss2 and Slco1a1) were further identified by targeted proteomic quantitative technology and their expression patterns were consistent with the results of 4D label-free proteomic analysis. CONCLUSIONS: Our study provided proteomics-based evidence that GJDD alleviated AFLD by modulating liver protein expression, likely through the modulation of lipid metabolism, bile acid metabolism and with exertion of antioxidant stress.

Effect of High-Intensity Interval Exercise versus Continuous Low-Intensity Aerobic Exercise with Blood Flow Restriction on Psychophysiological Responses: A Randomized Crossover Study.

This study compared the effect of continuous low-intensity aerobic exercise with blood flow restriction (LI-AE-BFR) versus high-intensity interval exercise (HIIE), matching total external mechanical work between conditions, on perceptual (exertion, pain, affective and pleasure) and physiological responses (heart rate [HR], blood lactate [BL] and muscle fatigue). Ten healthy untrained men (25.6 ± 3.78 years old; 75.02 ± 12.02 kg; 172.2 ± 6.76 cm; 24.95 ± 3.16 kg/m²) completed three visits to the laboratory. In visit 1, anthropometry, blood pressure and peak running velocity on the treadmill were measured. In visits 2 and 3, participants were randomly assigned to HIIE or LI-AE-BFR, both in treadmill. HIIE consisted of 10 one-minute stimuli at 80% of peak running velocity interspersed with one-minute of passive recovery. LI-AE-BFR consisted of 20-minutes of continuous walking at 40% of peak running velocity with bilateral cuffs inflated to 50% of arterial occlusion pressure. BL and maximum isometric voluntary contraction (MIVC - fatigue measure) were measured pre- and immediately post-exercise. HR, rating of perceived exertion (RPE), and rating of perceived pain (RPP) were recorded after each stimulus in HIIE and every two minutes in LI-AE-BFR. Affective response to the session, pleasure, and future intention to exercise (FIE) were assessed 10 minutes after the intervention ended. Increases in BL concentrations were greater in HIIE (p = 0.028; r = 0.51). No effects time or condition were reported for MIVC. HR was higher in HIIE at all analyzed time points (p < 0.001; d = 3.1 to 5.2). RPE did not differ between conditions (p > 0.05), while average session RPP was higher in LI-AE-BFR (p = 0.036; r = 0.46). Affective positive response (p = 0.019; d = 0.9) and FIE (p = 0.013; d = 0.97) were significantly higher in HIIE. Therefore, HIIE elicited higher physiological stress, positive affective response, and intention to engage in future exercise bouts compared to LI-AE-BFR.