Ana Carolina Paludo

Isokinetic knee strength is commonly normalized to body mass, although this assumes that torque increases in direct proportion to mass. This study tested whether conventional ratio scaling removed body-mass dependence from concentric knee-extensor and knee-flexor peak torque in elite female soccer players. Sixty-seven preseason assessments from 46 players were analyzed. Bilateral mean peak torque was calculated at 60°·s⁻¹ and 300°·s⁻¹, and log-linear models estimated the exponent b in torque = a·mass^b using player-clustered standard errors. Player-mean sensitivity analyses and leave-one-player-out internal cross-validation were also performed. Body mass was positively associated with absolute torque but negatively associated with torque divided by body mass. The estimated exponents were 0.562 and 0.551 for quadriceps and hamstring torque at 60°·s⁻¹ and 0.349 and 0.374 at 300°·s⁻¹. All confidence intervals excluded 1.00. Player-mean estimates were similar, and cross-validated residuals showed little remaining linear association with body mass within this cohort. Knee torque increased with body mass, but less than proportionally. Direct division by body mass therefore overcorrected for size and tended to favor lighter players. Absolute torque should continue to be reported, while the sample-specific exponents require external validation before broader application.

Introduction: Osteoporosis and osteopenia increase the risk of fractures, impair physical function, and may lead to loss of independence in postmenopausal women. This study examined differences in muscle strength imbalances and gait performance in postmenopausal women with healthy and low bone mineral density (BMD). Methods: In this cross-sectional study, a total of 85 participants underwent body composition and BMD measurements using dual-energy X-ray absorptiometry (DXA, Hologic QDR Horizon A). Muscle strength was evaluated using a handgrip strength test, and knee flexor and extensor strength were analyzed using an isokinetic dynamometer (Humac Norm CSMI). Gait performance was evaluated by a 10 m walking test, a 3 m backward walking test, and a 6-minute walking test. According to whole-body BMD T-score, participants were divided into a Healthy BMD group (n = 30) and a Low BMD group (n = 55). Normality was assessed using the Shapiro–Wilk test. Between-group differences and side-to-side differences in strength parameters were analyzed using the Mann–Whitney U-test, and associations between gait parameters, muscle strength, and BMD were examined using Spearman’s rank correlation coefficient. Additionally, multivariable analyses, including multivariate analysis of covariance (MANCOVA) and binary logistic regression, were performed to adjust for age and lean body mass. Statistical significance was set at p < 0.05. Results: Low BMD status was associated with reduced muscle strength, particularly lower knee extensor strength. After adjustment for age and lean body mass, right knee extensor strength remained independently associated with low BMD status in binary logistic regression (OR = 0.957, 95% CI: 0.927– 0.988, p = 0.007). No significant association was observed between gait performance and BMD. Discussion: These results suggest that lower limb muscle strength, particularly knee extensor strength, may be a relevant functional factor to consider in postmenopausal women with low BMD, as reduced strength may be associated with increased fracture risk in older women.

The purpose of this study is to examine the impact of COVID-19 infection on heart rate variability (HRV) in female soccer players, with a focus on identifying changes in autonomic regulation before, during, and after a COVID-19 positive test. Seven elite female soccer players (age: 20.14 ± 6.41 years, height: 162.43 ± 4.32 cm, weight: 51.73 ± 5.65 kg) were included in the analysis after consistently recording their HRV during the specified period. Morning HRV measures were completed using photoplethysmography via the HRV4 training smartphone application, a validated tool for field-based monitoring, along with self-reported data. The players were tracked for at least 30 consecutive days before testing positive for COVID-19 using a polymerase chain reaction (PCR) test. They were also requested to record their HRV while they had COVID-19 until a negative PCR result was obtained. The study presents data on RMSSD, LnRMSSD and HR for the 30 days prior to COVID-19, as well as for the 3 days (day − 3), 2 days (day − 2), and 1 day (day − 1) leading up to COVID-19. Also, data for the first 5 days following a positive COVID-19 test are included. The results of this study indicated that LnRMSSD measurements were significantly lower 2 days (day − 2) and 1 day (day − 1) before the onset of COVID-19, as well as during the first four days following a positive COVID-19 test, compared to baseline. In addition, RMSSD measurements were significantly lower during the first 4 days after a positive COVID-19 test, while resting heart rate was significantly higher during the first and second days following a positive COVID-19 test, compared to baseline. Our findings suggest that reductions in LnRMSSD, reflecting decreased parasympathetic activity, may serve as early indicators of COVID-19 infection in elite female soccer players, potentially allowing for pre-symptomatic detection through daily HRV monitoring.

INPLASY202530099 The impact of COVID-19 on the physical performance of soccer players during the acute infection and post-recovery phases: A systematic review. Keywords: SARS-CoV-2, return to play,…

Introduction: The study aimed to describe the practices and perspectives of Czech football coaches regarding the monitoring of players’ training load and physical performance, with a focus on identifying key barriers and preferred sources of information.Methods: A total of 235 football coaches completed an online survey comprehending training load monitoring methods, physical performance assessments, barriers to implementation, and information sources.Results: Among respondents, 93.7% reported monitoring training load, with training diaries (70%) being the most utilized method for external load measures and heart rate (45%) for internal load. Despite this, 42.7% of coaches did not monitor internal load and 21.7% did not conduct physical fitness evaluations. The most frequently reported barrier was a lack of resources (74.5%), though elite-level coaches (52.8%) and strength and conditioning coaches (75%) identified human resources as their primary limitation. Across all levels, the Football Association was the preferred source of information (61.7%).Conclusion: The findings highlight the predominance of traditional monitoring practices among the Czech football coaches, alongside with notable gaps in internal load tracking and fitness evaluation. The resource constraints remain a major barrier. Practical recommendations include promoting economical monitoring tools, such as RPE, and enhancing collaboration among stakeholders to improved monitoring strategies. The Football Association's play a key role on support these efforts.

This study investigated the test–retest reliability of the countermovement-jump (CMJ) test using Kistler force plates to assess explosive power in top-level para-karate athletes with intellectual impairment (II) or Down syndrome (DS). Forty-four athletes (II, n = 20; DS, n = 24) were evaluated during the 2023 World Karate Championships. Each performed two CMJs with a 1-min rest between. Key parameters measured included jump height, force index, and maximal rate of force development. Results showed no significant differences between test and retest for either group. Athletes with II exhibited better reliability metrics (e.g., intraclass correlation coefficient [ICC] = .381–.953) compared with DS (ICC = .029–.64). The study concludes that the CMJ test is highly reliable for assessing explosive power in athletes with II, while DS requires careful protocol adjustments to enhance reliability, ensuring consistent data for coaches and sport scientists.

Regular physical exercise is mandatory for health, regardless of the modality. However, it is recommended to include resistance exercises in addition to aerobic exercises. The study aimed to verify the time trends of the resistance training practice in a representative sample of Brazilian adults from 2006 to 2018. The ecological time-series study used the secondary data obtained from the Risk Factors Surveillance System for Chronic Non-communicable Diseases (VIGITEL) of the Brazilian Ministry of Health. The search resulted in a representative sample of 677,819 Brazilian adults from 18 to 120 years old. The resistance training practice was self-reported. Analyses were performed in the overall sample as well as by age groups. Prais-Winsten regressions were used to analyze the time trends, and the significance level was set at p < 0.05. In the overall sample, there was an annual growth rate (AGR) of 0.47% (95% confidence interval (95%CI) = 0.03; 0.90, p= 0.03) in resistance training practice. For the age groups, we found a significant increase in resistance training practice over time in those aged 35-54 years (AGR = 0.65%; 95% CI = 0.44; 0.86, p= 0.001), 55-64 years (AGR = 0.41, 95% CI = 0.23; 0.58, p=0.001) and ≥ 65 years (AGR = 0.22, 95% CI = 0.07; 0.37, p = 0.007). Based on the results, the resistance training practice increased among Brazilians from 2006 to 2018, particularly among those over 35 years old

RESUMO Objetivo Avaliar o consumo alimentar, comportamento de risco para transtornos alimentares e percepção da imagem corporal em adolescentes praticantes de judô. Métodos Estudo transversal com adolescentes judocas participantes da Federação Paranaense de Judô. Os dados foram coletados por meio de um questionário on-line, contendo os instrumentos Body Shape Questionnaire (BSQ) para avaliar percepção da imagem corporal, o Eating Attitudes Test (EAT-26) para identificar comportamentos de risco para transtornos alimentares e o Recordatório alimentar de 24 horas para análise da ingestão alimentar. A insatisfação com o peso corporal foi obtida pelo relato dos que gostariam de ganhar ou perder peso. Resultados Participaram 57 judocas de ambos os sexos, maioria sexo masculino (54,3%; n=31). Ausência de comportamento de risco para transtorno alimentar (63,1%; n=36) e insatisfação com a imagem corporal (75,4%; n=43) foram prevalentes entre os judocas. Entre os que apresentaram insatisfação com a imagem corporal (36,8%; n=14), observou-se que 9 (15,78%) também mostraram comportamento alimentar de risco para transtornos alimentares pelo teste EAT-26 (p=0,002). Houve associação entre insatisfação com o peso e comportamento de risco para TA (p=0,034), representado pelo EAT positivo para 26,31% (n=15) dos adolescentes. Identificou-se valores de ingestão alimentar insuficientes de energia e carboidratos, bem como consumo elevado de proteínas, e inadequação na ingestão para a maioria dos micronutrientes. Conclusão A maioria dos atletas não apresentou comportamento de risco para TA e estavam satisfeitos com sua imagem corporal. Diate da inadequação no consumo alimentar, destaca-se a importância das ações de educação alimentar e nutricional voltadas para este público.

Highlights Samba rehearsals can increase cardiorespiratory function in dancers up to 19% of VO2max. Samba rehearsals can decrease up to 1.9kg of fat mass and increase 1.3kg of lean body mass. In a samba rehearsal session, dancers spend 50% of their time at an intensity above 83% of the maximum. ABSTRACT Objective: To investigate the effect of 12 weeks of rehearsals on cardiorespiratory parameters and body composition in Brazilian samba dancers belonging to a first-league samba school. Methods: Twenty-six women