International journal of exercise science最新文献

Law enforcement agencies typically have recruits complete fitness assessments without personal protective equipment (PPE). PPE negatively impacts performance. Greater strength and power could alleviate performance decrements due to the extra load, termed the tactical deficit (TD). The purpose of this study was to examine whether lower-body strength or power related to the TD in civilians performing police tasks. Twenty participants (12 men, 8 women) completed baseline tests, including: standing broad jump (SBJ); relative SBJ; absolute and relative isometric leg/back dynamometer (LBD) and one-repetition maximum hexagonal bar deadlift (HBD). In two other sessions, participants completed four police tasks, either unloaded or loaded (PPE=~8-10 kg), in a counterbalanced order: vertical jump (VJ), 75-yard pursuit run (75PR), 74.84-kg body drag, and 500-yard run. The VJ was also used as a power metric, with peak anaerobic power and power:body mass (P:BM) derived. Paired samples t-tests investigated differences between unloaded/loaded conditions for each task for each sex. Independent samples t-tests compared the sexes. Pearson's correlations derived relationships between strength and power tests with each task TD for each sex. Load negatively impacted task performance (p≤0.011); males generally outperformed females (p≤0.044). Superior SBJ, relative SBJ, VJ, P:BM, and absolute and relative HBD related to a smaller 75PR TD (r=-0.582 to -0.838). Greater absolute and relative HBD related to a lower body drag TD (r=-0.576 to -0.618) in men. For women, the relative SBJ related to a smaller VJ TD (r=-0.727). Developing lower-body strength and power could offset TD in foot pursuit and dragging tasks for personnel.

The blood pressure dipping response to acute resistance training exercise (RTE) is scarce in the literature. We determined the inter-individual blood pressure (BP) dipping variability of normotensive (NT) and hypertensive (HT) men completing two modalities of a single session of RTE. Volunteers (NT n = 21, HT n = 20) underwent a non-exercise control (CTRL), RTE high-sets low-repetitions (HSLR), and RTE high-repetitions low-sets (HRLS) conditions. Twenty-four-hour ambulatory BP monitoring recorded diurnal and nocturnal systolic (SBP) and diastolic (DBP) BP. Non-significant interactions were found between the category of individuals and the experimental conditions on the SBP (p = 0.511, η² _p = 0.02) and DBP (p = 0.807, η² _p = 0.01) differences. Diurnal SBP (p = 0.0001) and DBP (p ≤ 0.0001) were lower in the NT than in the HT groups. Nocturnal SBP (p ≤ 0.0001) and DBP (p = 0.014) were lower in the NT than in the HT groups. The percentage of dipping responders for SBP in the CTRL condition were 71.4% for NT and 70.0% for HT, in the HRLS condition were 66.7% for NT and 60.0% for HT, and in the HSLR condition were 57.1% for NT and 60.0% for HT. The dipping responders for DBP in the CTRL condition were 57.1% for NT and 60.0% for HT, in the HRLS condition were 61.9% for NT and 70.0% for HT, and in the HSLR condition were 71.4% for NT and 65.0% for HT (p > 0.05 for all). In conclusion, the dipping response was similar between NT and HT individuals. The proportion of responders was similar between NT and HT individuals completing acute RTE.

Various exercise types may slow disease progression and improve physical function for people with Parkinson's disease (PWP), including community-based boxing programs (CBP). Recent research suggests that high-intensity exercise may result in greater benefits for PWP. Participants in CBP, which are typically self-paced, may not be reaching this optimal intensity. This study examines if it is feasible and beneficial for PWP to perform high-intensity exercise in a CBP. Seven subjects diagnosed with Parkinson's disease participated in a multimodal CBP twice a week for six weeks while wearing heart rate (HR) monitors to help maintain an HR of 70-85% of the age-predicted maximum. Subjects completed pre- and post-testing, including Functional Gait Assessment (FGA), Five Time Sit to Stand (5xSTS), Timed Up and Go (TUG), and Activities-Specific Balance Confidence Scale (ABC). Data were analyzed using descriptive statistics, and paired-sample t-tests were used to evaluate improvements (p <0.05) from baseline. Both Cohen's d and minimally clinically important difference (MCID) were used to evaluate effect size and efficacy. Subjects completed 37.99±8.20 minutes of high-intensity interval training (HIIT) exercise. Results demonstrated significant improvement in FGA, TUG, and 5xSTS with large effect sizes and surpassing the MCID for the FGA and 5XSTS. It is feasible for PWP to perform high-intensity exercise in a CBP, which may improve balance and functional strength.

The purpose of this study was to investigate the effect that mental fatigue, as induced by a Stroop test, has on resistance training performance outcomes such as muscular endurance, power output, and neuromuscular activation. Seven female college-aged NCAA Division III student-athletes with at least one year of resistance training experience and were within the 50th percentile for maximal aerobic capacity provided informed consent for participation. During two separate visits, using a within-subject crossover experimental design, subjects completed either the experimental or control condition. Subjects then completed a to-failure leg press test at 50% of their 1-repetition maximum (1RM) followed by an isometric midthigh pull (IMTP) attempt with electromyography (EMG) analysis. The experimental condition consisted of a 30-minute Stroop test, while the control condition consisted of watching 30 minutes of a sitcom. Both activities were completed while cycling at 40% of their aerobic capacity. A NASA Task Load Index (TLX) inventory was administered following the completion of each cycling session to determine the perceived workload and mental fatigue of each activity. While the mentally fatiguing condition was significantly more mentally fatiguing (p = 0.02) than the control condition, mental fatigue did not statistically affect any of the evaluated performance outcomes (p>0.05). These findings suggest that mental fatigue, a common symptom of psychological stress, does not affect resistance-training-related performance outcomes among female athletic populations.

The aim of this study was to determine the validity, reliability, and sensitivity of a new linear position transducer (LPT) device (RepOne) to a previously validated LPT (Tendo) during the barbell back squat and bench press exercises. Fourteen recreationally resistancetrained individuals (7 males and 7 females) performed three repetitions for the back squat and bench press at loads ranging from 30-90% 1RM. Both devices recorded average (ACV) and peak (PCV) concentric velocities concurrently for every repetition at each load. Significant correlations were observed between RepOne and Tendo during the back squat (PCV: r = 0.90-0.99, p < 0.01; ACV: r = 0.84-0.99, p < 0.01), bench press (PCV: r = 0.74-0.99, p < 0.01; ACV r = 0.81-0.99, p < 0.01). ICCs reveal good to excellent reliability between devices for back squat (PCV, 0.85-0.99; ACV, 0.83-0.99) and bench press (PCV, 0.79-0.99; ACV, 0.83-0.99). Bland-Altman plots revealed greater bias during PCV for both exercises across intensities (back squat, 0.072 to 0.110 m/s; bench press, 0.039 to 0.107 m/s), although ACV bias was lower for both exercises (back squat, -0.002 to -0.029 m/s; bench press, -0.022 to 0.015 m/s). The RepOne device generally exhibited higher smallest detectable change (SDC) values compared to the Tendo, except for specific loads in certain conditions. Additionally, the RepOne device demonstrated higher smallest worthwhile change (SWC) values than the Tendo unit for most loads in back squat ACV. Collectively, the RepOne exhibits strong validity and reliability comparable to the Tendo across both barbell back squat and bench press exercises, despite some variations in sensitivity metrics like SDC and SWC, indicating its efficacy for resistance training application.

Morphologic Achilles tendon properties obtained via diagnostic ultrasound imaging are valuable in understanding Achilles tendon health and injury. Currently, limited information exists regarding Achilles tendon morphological properties amongst active aging adults based upon Victorian Institute of Sport Assessment (VISA-A) scores. Achilles tendon morphologic properties defined by VISA-A score groupings allow clinicians and researchers to compare data values amongst current patients. Purpose: Comparison of physically active aging adults Achilles tendon morphological properties with various VISA-A scores or a previous Achilles tendon rupture. A convenience sample of 121 participants (71 females, 50 males) at least moderately active and 50 years old, were recruited. Participants completed a VISA-A survey, and assigned groups by scores (Group 1: 90-100, Group 2: 70-89, Group 3: 45-69, Group 4: Previous Achilles tendon tear). Achilles tendon ultrasound imaging occurred at the malleolar line (The apex of the medial and lateral malleolus). Following imaging Achilles tendon cross-sectional area (CSA), thickness, and elastography were measured and analyzed. Participants with a previous Achilles tendon rupture displayed significantly larger tendon CSA and thickness compared with other groups (p<0.05). Individuals with VISA-A scores from 45-69 displayed significantly larger tendon CSA and thickness than participants with scores greater than 90 (p<0.03). No significant differences were noted for elastography between groups (p>0.05). Achilles tendon morphological differences exist based upon pain level in physically active aging adults. Diagnostic ultrasound may be used during assessment and rehabilitation of injured tendon tissue to inform about current tendon tissue properties.

The aim of this study was to compare the warm-up effects of a treadmill walking warm-up (TW) with a dynamic warm-up (DW) on the responses to cardiopulmonary exercise testing (CPET) in youth. A sample of 16 active youth (age 13.6 ± 1.8 yr) were tested for peak oxygen uptake (VO₂ peak) using the Fitkids treadmill test protocol on 2 nonconsecutive days following different 6-min warm-up procedures. The TW consisted of walking on a treadmill at 2.2 mph and 0% grade whereas the DW consisted of 12 bodyweight exercises with a 2 kg medicine ball. Maximal heart rate (HR) was significantly higher following DW vs TW (200.8 ± 6.16 vs. 197.9 ± 7.3 bpm, respectively; p < 0.05), whereas no significant differences were found between DW and TW for VO₂ peak (50.5 ± 9.9 vs 50.6 ± 11.1 ml/kg/min), maximal minute ventilation (V_E; 93.0 ±21.4 vs. 92.7 ±21.2 L/min), maximal respiratory exchange ratio (1.19 ± 0.08 vs 1.22 ± 0.08), and total exercise test time (668.1 ± 103.5 vs 686.3 ± 97.0 s), respectively. During the Fitkids treadmill test protocol HR and V_E were significantly higher following DW vs TW at stage 1, stage 2, stage 3 and stage 4, and oxygen uptake was significantly higher following DW vs TW during stage 1 (all p < 0.05). Findings indicate a DW elicits a higher maximal HR and higher submaximal HR, V_E, and oxygen uptake values than TW during CPET in youth, although no differences in VO₂ peak were observed.

Understanding the Relative Age Effect (RAE) in female volleyball can provide a deeper insight into potential developmental advantages and selection biases between playing positions and volleyball-related performance characteristics. This study aimed to investigate the occurrence of the RAE in adolescent female volleyball players according to the playing position and the possible differences in anthropometric and performance characteristics between the relative age groups. The study involved 193 young female volleyball players from 12 different regions and 108 sports clubs from all over Greece, with an average age of 14.53 ± 0.31 years, height of 1.67 ± 0.07 m, weight of 57.20 ± 9.10 kg, and body mass index (BMI) of 20.34 ± 2.50. RAE was identified by the birth quarter of each player, categorizing thus the total sample into four sub-groups: Q1 (January-March), Q2 (April-June), Q3 (July-September), and Q4 (October-December). Anthropometrics, upper and lower limb power, agility, flexibility, and trunk strength were also assessed. The distribution of volleyball players differed significantly across birth quarters (34.19% of Q1, 25.9% of Q2, 22.79% of Q3, 17.09% of Q4; χ² = 11.788, p = 0.008). Analysis revealed no significant association between birth quarter and playing position (χ² = 11.314, p = 0.730). Present study's results indicated no RAE in young female volleyball players regarding their playing position. Also, performance tests did not differ significantly among the RAE groups. Moreover, despite athletes' early specialization based on assigned playing positions, no differences in athletes' position-related performance characteristics were observed. These findings suggest that interventions to mitigate RAE should be considered to ensure equitable development opportunities across all playing positions.

Current law enforcement body drag tests may use dummy masses that are underweight compared to current population norms. This study aimed to determine differences in 74.84-kg and 90.72-kg body drag times when performed with a standard (pick up and stand with dummy prior to dragging), adapted (incorporation of time to lift dummy to standing), and preferred (drag with any technique) technique. Forty-three (24 males, 19 females) physically-active, healthy civilians (surrogate population for police recruits) completed drags over 9.75 m with 74.84-kg and 90.72-kg dummies using the three techniques previously stated. A 2 (mass) × 3 (technique) within-factorial ANOVA (p < 0.05), with Bonferroni post hoc, derived any dummy and technique differences. Thirty-five participants completed all the standard and adapted drags; all participants completed the preferred drag. There were significant main effects for dummy mass (F _(1,34) = 14.762, p < 0.001) and technique (F _(2,33) = 23.272, p < 0.001). Participants dragged the 74.84-kg dummy faster than the 90.72-kg dummy. The standard drag was completed faster than the adapted and preferred drags (p < 0.001). The adapted drag was completed faster than the preferred drag (p = 0.024). Even if a recruit is assessed with a lighter dummy, they need the capacity to perform heavier drags in the field. Activity-specific strength training during academy could aid this process. Though the time was slower, the adapted technique may offer information the standard technique does not as it includes the lifting portion of the drag. The preferred technique allowed all participants to complete the task, which could influence the drag techniques allowed if agencies increase testing dummy masses.

The objective of this study was to investigate the effectiveness of Simulated Equestrian Therapy and Neuro-Motor Therapy in improving Motor Proficiency among Down syndrome children using a double-blinded Randomized Controlled Trial. This study was conducted at Dar-ul-Sukun Institute and Dr. Ziauddin Hospital from April to September 2023 by enrolling a total of 56 participants with Down syndrome (DS) after obtaining informed, voluntary assent from the guardians of the participants. Each participant was allocated randomly to the treatment group (n = 28) that received Simulated Equestrian Therapy (SET) and the control group (n = 28) that received Neuro-motor Therapy (NMT) using the envelop method of simple random sampling. The participants and their guardians were blind to the allocations. Participants' blood pressure and heart rate were recorded before and after each session to ensure safety. Each participant was assessed at baseline and after 6^th and 12^th week of intervention using Bruinink's test of motor proficiency (BOT-2). The data was analyzed using Medcalc software. The results reveal significant findings for improving motor proficiency after 12^th week of intervention of SET and NMT. No protocol was found to be superior to another in improvement of the tested parameters. Hence, our study concludes that SET and NMT effectively improve motor proficiency among DS children. However, studies with a follow-up period should be conducted to further evaluate these therapies' long-term benefits.