Reliability and validity of a low-cost, wireless sensor and smartphone app for measuring force during isometric and dynamic resistance exercises.

The aim of this study was to investigate the reliability and validity of an affordable wireless force sensor in measuring mean and peak forces during resistance training.A Suiff Pro wireless force sensor (Suiff, Spain) and a MuscleLab force platform (Ergotest, Norway) were used concurrently to assess tensile load and the ground reaction force resulting from an upright row exercise. Thirteen participants (28.2 ± 5.7 years, 76.2 ± 9.6 kg, 178.2 ± 9.2 cm) performed the exercise under three velocity conditions and isometrically. Each condition involved three sets of exercise. Mean (Fmean) and peak (Fpeak) force values from both sensors were collected and compared.Suiff Pro exhibited excellent reliability for Fmean and Fpeak (ICCs = 0.99). When compared to the criterion measures, Suiff Pro showed trivial standardized bias for Fmean (Mean = 0.00 [CI 95% = 0.00 to 0.01]) and Fpeak (-0.02 [-0.04 to 0.00]). The standardized typical error was also trivial for Fmean (0.03 [0.02 to 0.03]) and Fpeak (0.07 [0.05 to 0.09]). Correlations with the MuscleLab force platform were nearly perfect: Fmean (0.97 [0.94 to 0.98]; p<0.001); Fpeak (0.96 [0.92 to 0.97]; p<0.001).The findings demonstrate that the Suiff Pro sensor is reliable and valid device for measuring force during isometric and dynamic resistance training exercises. Therefore, practitioners can confidently use this device to monitor kinematic variables of resistance training exercises and to obtain real-time augmented feedback during a training session.

Initial Maximum Push-Rim Propulsion and Sprint Performance in Elite Men's Wheelchair Basketball.

OBJECTIVES: This study sought to report the reliability (intrasession) values of initial maximum push-rim propulsion (IMPRP) and sprint performance in elite wheelchair basketball (WB) players and to assess the involvement of strength in sprint capacity. METHODS: Fifteen Spanish international WB male players participated in this study. The maximum single wheelchair push from a stationary position (IMPRP) and the sprint performance (ie, 3, 5, and 12 m) of WB players were measured in this study. RESULTS: IMPRP mechanical outputs V, Vmax, P, Rel. P, F, and Rel. F variables presented high reliability values (intraclass correlation coefficient [ICC] ≥ .92; coefficient of variation [CV] ≤ 8.04 ± 7.37; standard error of measurement [SEM] ≤ 29.92), but the maximum strength variables Pmax, Rel. Pmax, Fmax, and Rel. Fmax (ICC ≥ .63; CV ≤ 13.19 ± 16.63; SEM ≤ 203.76) showed lower ICC values and by contrast higher CV and SEM values. The most substantial correlations were identified between maximum IMPRP values (ie, V, Vmax, P, Rel. P, F, and Rel. F) and sprint performance in 3 m (r ± confidence limits ≥ -0.74 ± 0.22, very large; R2 ≥ .55), 5 m (r ± confidence limits ≥ -0.72 ± 0.24, very large; R2 ≥ .51), and 12 m (r ± confidence limits ≥ -0.67 ± 0.27, large; R2 ≥ .44). CONCLUSIONS: The IMPRP test and sprint tests (3, 5, and 12 m) are practical and reliable for measuring strength and speed in WB players. In addition, there were large to very large associations among strength variables (ie, P, Rel. P, F, and Rel. F) and all sprint variables. This could indicate a need to implement specific strength exercises in WB players to improve sprint capacity.

Efficacy of physical exercise on sleep quality in patients with chronic kidney disease: a systematic review and meta-analysis.

BACKGROUND AND OBJECTIVE: To revise and critically summarize the available scientific evidence regarding the effect of exercise on sleep quality in patients with chronic kidney disease (CKD). METHODS: A systematic review of randomized controlled trials (RCTs) and comparative studies was conducted, searching MEDLINE/PubMed, SPORTDiscus, and Scopus using keywords "Exercise", "Physical Activity", "Chronic Kidney Disease," and "Sleep". The methodological quality of included studies was assessed using the PEDRo and MINORS scales. RESULTS: A total of 8 RCTs and 3 comparative studies were included, showing a low (n = 1), fair (n = 7), and good (n = 3) methodological quality. Most of the studies included patients undergoing hemodialysis (HD) (n = 8). Self-reported sleep quality (n = 9), sleepiness (n = 2), and objective sleep status (n = 2) were the main outcomes analyzed. The most frequent exercise interventions included aerobic training (n = 7), resistance training (n = 2), or a combination of both (n = 4). Generally, exercise induced positive effects on the reported outcomes. Data synthesis indicated that participants who exercised obtained significant improvements on their self-reported sleep quality in comparison with those included in the control groups, with a mean difference in the Pittsburgh Sleep Quality Index of - 5.27 points (95% CI - 7.76, - 2.77; p < 0.001). CONCLUSION: Preliminary scientific evidence indicates that patients with CKD, especially those undergoing HD, report improvements in self-reported sleep quality after taking part in aerobic exercise programs, while combined training interventions yielded diverse findings. The effects of exercise on sleepiness and objective sleep status were backed by few studies with mixed results.

Effects of physical exercise in people with epilepsy: A systematic review and meta-analysis.

BACKGROUND: Studies suggest that physical exercise lead to improvements in the psychosocial dimension, associated comorbidities as well as to a higher quality of life (QoL) in people with epilepsy. However, there is a need to provide evidence-based guidelines for its prescription. Therefore, this review aimed to systematically evaluate and meta-analyze the available data on the potential effects of physical exercise training programs in people with epilepsy. METHODS: Four electronic databases (MEDLINE/PubMed, PEDro, SPORTDiscuss and Scopus) were searched systematically from their inception until April 2022 for randomized controlled trials (RCTs), comparative studies and non-controlled studies that provided information regarding the effects of physical exercise training programs on people with epilepsy. The studies' methodological quality assessment was performed using the PEDro, the MINORS and the Quality Assessment Tool for Before-After Studies with No Control Group scales. For the meta-analysis, inverse variance or generic inverse variance was use to report mean difference or standardized mean difference for continuous data and their 95% confidence intervals (CI). Heterogeneity was assessed with the Chi-squared test and I2 test. RESULTS: After removing duplicated studies, 82 results were retrieved by the literature search and 14 were eligible for full text search. Finally, 14 studies with a methodological quality ranging from good to low quality met the inclusion criteria. Totally, 331 people with epilepsy were evaluated. Significant changes between preand post-intervention results in the exercise intervention groups were observed for QoL, fitness level, psycho-affective and neurocognitive outcomes. Findings from the meta-analysis indicated that moderate exercise led to a non-significant decrease (p = 0.08, Chi-squared test) in seizure frequency (SMD 0.33 95% CI 0.04; 0.70), while a significant effect of exercise was observed on QoL with a mean improvement of 4.72 percentage points (95% CI 0.58; 8.86, p = 0.03). CONCLUSION: Improvements on QoL, fitness level, psycho-affective and neurocognitive outcomes can be achieved through exercise training in people with epilepsy. Altogether, the findings suggest that people with epilepsy can benefit from exercising.

Reliability and validity of field-based tests for assessing physical fitness in gymnasts

Objective: This systematic review aimed at analysing the reliability and validity of field-based tests for assessing physical fitness in gymnasts.MethodThree electronic databases (PubMed, SPORTDiscus, and Scopus) were searched up to March 2022, in order to identify studies that assessed the psychometric properties of field-based physical fitness test among gymnastics.ResultsA total of 16 studies on several gymnastics modalities (artistics n = 11; rhythmic n = 3, artistics and rhythmic n = 1; aerobic n =  1), were analyzed. All studies reported on reliability measured through test-retest design. Validity was reported in only four studies. Regarding specific tests, the split test (ICC = 0.998), and the handstand (ICC= 1) showed the highest test-retest reliability. The greater validity values were achieved by the split test (r2 = 0.52), hanging pikes test (r2 = 0.86), and handstand test (r2 = 0.65).ConclusionA great variety of both specific and non-specific physical fitness tests have been analyzed in the field of gymnastics. The side split test, the handstand test, the vertical jump test, the 20-m run test, the agility test, and the aerobic gymnast anaerobic test could be useful tools to assess flexibility, strength, balance, muscular power, speed, agility, and cardiorespiratory fitness in gymnasts. Further investigations analyzing absolute reliability and criterion validity are needed. (AU)

Initial Maximum Push-Rim Propulsion and Sprint Performance in Elite Women's Wheelchair Basketball: Differences Between Players' Functional Classification.

The aim of the present study was to determine, for the first time in elite women's wheelchair basketball, the differences in the initial maximum push-rim propulsion (IMPRP), mechanical outputs, and sprint performance between A category (≤2.5 class) and B category (≥3 class) players. A secondary aim was to assess the association between IMPRP mechanical outputs and sprint performance to determine the influence of specific strength in the latter. Sixteen Spanish women's wheelchair basketball players participated in this study: A category (n = 9, International Wheelchair Basketball Federation [IWBF] classification range: 1-2.5 points) and B category (n = 7, IWBF classification range: 3-4.5 points). All the players undertook 2 tests: the IMPRP test to measure the strength variables and the 3-, 5-, and 12-m sprint test. B category players reported significantly better performance values in almost all the IMPRP variables and all the sprint distances than A category players. Large to very large significant correlations were observed among IMPRP absolute mechanical outputs (excepting mean power) and sprint performance (3, 5, and 12 m) for all the participants. When the group was divided according to categories A and B, the significant differences observed in the whole group decreased in both groups, although some relationships were large or very large. The IMPRP test and sprint test (3, 5, and 12 m) seemed to be sensitive to differentiate the level between the 2 functional categories. In addition, there was a high association between strength and sprint variables, which shows that greater strength could improve sprint capacity.

Influence of upper-limb muscle strength on the repeated change of direction ability in international-level wheelchair basketball players.

This study aims 1) to compare repeated change of direction ability (rCODA) and bench press (BP) between low (A category, ≤2.5) and high (B category, ≥3.0) sport classes and 2) to analyse the relationships between rCODA and BP performance in a sample of wheelchair basketball (WB) players. Seventeen world-class WB players volunteered participated in this study. All the players undertook two tests: the repeated (x12) Modified Agility T-test (rMAT) to measure the rCODA and the movement velocity in a BP test. No significant differences were observed between categories in the rMAT and BP. For the total sample, BP variables with a mean propulsive velocity of 1 m·s-1 (V1LOAD) largely correlated with all the full rMAT outcomes (r>-0.625; p< 0.05). Having a better BP could be favourable to perform repeated efforts and this seems particularly relevant in fatigue conditions, and especially for the B category players.

The Relationship between Resistance Exercise Performance and Ventilatory Efficiency after Beetroot Juice Intake in Well-Trained Athletes.

The assessment of ventilatory efficiency is critical to understanding the matching of ventilation (VE) and perfusion in the lungs during exercise. This study aimed to establish a causal physiological relationship between ventilatory efficiency and resistance exercise performance after beetroot juice (BJ) intake. Eleven well-trained males performed a resistance exercise test after drinking 140 mL of BJ (~12.8 mmol NO3-) or a placebo (PL). Ventilatory efficiency was assessed by the VE•VCO2-1 slope, the oxygen uptake efficiency slope and the partial pressure of end-tidal carbon dioxide (PetCO2). The two experimental conditions were controlled using a randomized, double-blind crossover design. The resistance exercise test involved repeating the same routine twice, which consisted of wall ball shots plus a full squat (FS) with a 3 min rest or without a rest between the two exercises. A higher weight lifted was detected in the FS exercise after BJ intake compared with the PL during the first routine (p = 0.004). BJ improved the VE•VCO2-1 slope and the PetCO2 during the FS exercise in the first routine and at rest (p < 0.05). BJ intake improved the VE•VCO2-1 slope and the PetCO2 coinciding with the resistance exercise performance. The ergogenic effect of BJ could be induced under aerobic conditions at rest.

Initial Maximum Push-Rim Propulsion and Sprint Performance in Elite Wheelchair Rugby Players.

García-Fresneda, A, Carmona, G, Padullés, X, Nuell, S, Padullés, JM, Cadefau, JA, and Iturricastillo, A. Initial maximum push-rim propulsion and sprint performance in elite wheelchair rugby players. J Strength Cond Res 33(3): 857-865, 2019-Wheelchair rugby (WR) is an increasingly popular Paralympic sport; however, the evidence base supporting the validity and reliability of field tests to assess the physical condition of WR players is in its infancy. Therefore, here, we aimed to evaluate the intrasession reliability of the initial maximum push-rim propulsion (IMPRP) test and the sprint test, and to determine the relationships between IMPRP mechanical outputs and sprint performance variables. We studied 16 Spanish WR players (aged 33 ± 9 years). The maximum single wheelchair push from a stationary position and the sprint performance (i.e., times for 3, 5, and 12 m, and the maximum velocity) of elite WR players were measured in this study. The intraclass correlation coefficient, coefficient of variation, and standard error of measurement for IMPRP variables were >0.85, <10.6%, and <16.76, respectively; the corresponding values for a linear sprint were >0.97, <3.50%, and <0.15. In relation to IMPRP mechanical outputs (i.e., acceleration, maximum acceleration, force, maximum force, power, and maximum power) and sprint performance (i.e., times for 3, 5, and 12 m, and the maximum velocity), significant and large associations were observed in the WR players (r ± confidence limit = -0.78 ± 0.17 to -0.90 ± 0.11; 0/0/100, most likely; R = 0.613-0.812; p < 0.001). These tests provide simple and reliable methods for obtaining accurate mechanical pushing capacities and sprint performances of WR competitors (the 61.4-80.1% variance in sprint performance was explained by the IMPRP variables). These relationships indicate a need to implement specific strength exercises in WR players with the aim of improving the IMPRP and therefore improving sprint capacity.