Leg length discrepancy is not a risk factor for plantar fasciitis.

PURPOSE: Plantar fasciitis (PF) is a main source of heel pain, and only about one-third of patients have bilateral symptomatic involvement, although age, body mass index (BMI), and physical activities are known risk factors. The high prevalence of unilateral involvement is poorly understood. We aimed to assess the potential association between PF and the leg length discrepancy (LLD) in unilateral PF. METHODS: A transversal case-control study was conducted from January 2019 to December 2020, including 120 participants allocated to two groups matched by BMI and sex: cases (with a diagnosis of PF; 50 ± 13 years) and control (without foot pain; 40 ± 15 years). For both groups, a difference greater than 0.64 cm in the scanometry determined the criteria for the presence of LLD. RESULTS: The multivariate logistic regression analysis showed an independent association of PF only with age (p < 0.001), and no association with LLD. We did not observe differences in the mean discrepancy (1.37 ± 0.83 cm in the PF group in comparison with 1.13 ± 0.37 cm in the control group, [p > 0.05]) or in the prevalence of LLD between groups (48% [n = 29] in the PF group compared with 42% [n = 25] in the control group, [p > 0.05]). In the PF group, 80% of the participants reported unilateral pain. We observed a higher prevalence of pain in the shorter limb (p < 0.05). CONCLUSION: Age was the only factor associated with the diagnosis of PF when groups were matched by sex and BMI. LLD was not an independent factor associated with the diagnosis of PF. However, when PF is unilateral, the shorter limb is more affected with 70% of prevalence. LEVEL OF EVIDENCE: Level III, case-control.

Progressive strength training can reverse sarcopenia stage in middle-aged and older adults regardless of their genetic profile.

The aim of this study was to verify the association of the ACTN3-R577X polymorphism with sarcopenia stage, according to the Revised European Consensus on the Definition and Diagnosis of Sarcopenia, in middle-aged and older adults, pre- and post- ST. In the 12-week longitudinal study, 71 middle-aged and older adults were evaluated; the participants were assigned to either control or intervention group. The intervention group underwent progressive ST three times a week. All participants underwent blood collection, DNA extraction, genotyping of the ACTN3-R577X polymorphism, anthropometric evaluations, and diagnostic tests for sarcopenia. The last two tests were repeated after 12 weeks. No association of the ACTN3-R577X polymorphism with sarcopenia stage was observed before and after 12 weeks. However, the intervention group remained non-sarcopenic (n = 25, p <0.05) or achieved changes in sarcopenia stage (from sarcopenic to non-sarcopenic) (n = 13, p <0.05). Our study demonstrates that progressive ST performed regularly can reverse or prevent sarcopenia regardless of genotype for the ACTN3-R577X polymorphism.

Effects of exercise on immune cells with tumor-specific activity in breast cancer patients and survivors: a systematic review and meta-analysis.

Exercise is effective for improving the physical and psychological health of breast cancer patients. However, there is still controversy around its role on the immune system. Therefore, this systematic review and meta-analysis is aimed to evaluate the effect of chronic exercise on the number and activity of the immune cells that can contribute to anti-tumor immune responses, such as natural killers (NK) cells, CD + 4, or CD + 8. The main hypothesis of this study was that exercise could improve the immune system or, at least, there will not be a reduction in the number or activity of immune cells because of exercise. The search was conducted in the PubMed and Web of Science databases. Out of 244 studies reviewed, 10 studies met the inclusion criteria. The studies included in the meta-analyses showed mixed results and no significant (p > 0.05) positive or negative effects of exercise interventions in women with breast cancer. Therefore, the current evidence indicates that exercise does not significantly improve or reduce the immune system; thus, the prescription of exercise must not be discouraged due to the effects on the number and activity of immune system cells, but should be recommended due to the well-known benefits in quality of life, physical function or fatigue, and the absence of negative effects on the immune system. Further studies are needed to evaluate the effects according to the type of exercise, the type of cancer, or the timing of the intervention.

Could sarcopenia-related mortality in end-stage renal disease be underpinned by the number of hospitalizations and cardiovascular diseases?

PURPOSE: To investigate the association between sarcopenia with the number of all-cause mortality, hospitalizations, and cardiovascular diseases in patients with end-stage renal disease (ESRD). METHODS: 247 patients with ESRD (women, n = 97) (66.6 ± 3.53 years) participated in this study. At baseline, all participants were measured with dual-energy X-ray absorptiometry and handgrip dynamometer and were prospectively followed up for 5 years. The European Working Group on Sarcopenia in Older People guidelines were utilized for Sarcopenia determination. Cox proportional hazard analysis adjusted for established risk factors was used to quantify the risk between Sarcopenia and all-cause mortality. RESULTS: Sixty-five participants (26%) were determined to have Sarcopenia at baseline and 38 (15%) have died during the follow-up. At baseline, Participants with Sarcopenia had lower body mass index and fat-free mass index. Moreover, through the 5-year follow-up, sarcopenic patients had higher number of cardiovascular disease (56.9% vs. 12.6%) and hospitalizations (93.8% vs. 49.5%) (all P < 0.0001). Sarcopenia was associated with significantly higher risk of mortality, [Hazard ratio = 3.3, (95% CI: 1.6-6.9), P = 0.001]. CONCLUSION: Sarcopenia may be a risk factor for hospitalizations, cardiovascular diseases, and all-cause mortality in patients with ESRD. These results provide support of the relevance in assessing sarcopenia in the clinical practice of chronic kidney disease and how muscle mass and strength may negatively impact the daily life of ESRD patients undergoing hemodialysis. Greater efforts at preventing muscle wasting and malfunctioning are needed through the worldwide healthcare system.

Analysis of different training load monitoring methods in youth women handball players

This study examined the association between different methods for training load (TL) monitoring during youth handball training. Distance covered, heart rate and session rating of perceived exertion [SRPE] were recorded during 12 training sessions in 14 youth women handball athletes (16.9±1.1 years). Internal load models based on SRPE and Edwards’ Trimp were calculated. An oscillatory feature was observed for the three methods of TL assessment (SRPE: 383±159 A.U., Edwards’ Trimp: 252±71 A.U., total distance: 3997±1291 m). A large correlation was found between Edwards’ Trimp and distance covered (r=0.59). A moderate correlation was observed for Edwards’ Trimp vs. SRPE (r=0.36), and between SRPE vs. distance covered (r=0.49). Shared variances of 13–35% were observed between TL methods comparisons. The results suggest that different constructs seem to be measured by each load model. Additionally, SRPE is a simple and low-cost method that might be used for TL monitoring in handball. (AU)

Effects of different strength training protocols on sarcopenia influencing parameters in older adults: a systematic review / Efeitos de diferentes protocolos de treinamento de força sobre parâmetros influenciadores da sarcopenia em idosos: uma revisão sistemática

INTRODUCTION: Sarcopenia is characterized by the reduction of skeletal muscle mass and its functionality. Several of the parameters that influence sarcopenia are modified by strength training. OBJECTIVE: To review the effects of different strength training protocols (frequency, duration, and intensity) on parameters that influence sarcopenia. METHODS: This is a systematic review of original, quantitative, observational studies, published between 2010 in 2020, in English, Spanish and Portuguese, and indexed in the SciELO, PubMed, and CAPES databases. The terms used search were: "muscle strenght" ("força muscular", "fuerza muscular"), "sarcopenia" ("sarcopenia"), "aging" ("envelhecimento", "envejecimiento"), "olders" ("idosos", "ancianos"), "strength training" ("treinamento de força/resistência", "entrenamiento de fuerza"). 215 articles were retrieved and 11 met the inclusion criteria, being included in the review. RESULTS: Among the 11 studies analyzed, it is observed that strength training applied in different protocols was efficient in improving parameters such as muscle mass and strength, body balance, and performance in diagnostic tests of sarcopenia. CONCLUSION: This review highlights the benefits of the practice of strength exercise in different protocols on parameters that influence the onset of sarcopenia in older adults. The exercise of strength is presented as an applicable, practical, and non-pharmacological means of preventing sarcopenia.

INTRODUÇÃO: A sarcopenia é considerada uma patologia caracterizada pela redução da massa muscular esquelética e da sua funcionalidade, sendo que vários dos parâmetros que influenciam sobre a sarcopenia sofrem interferência do treinamento de força. OBJETIVO: Revisar os efeitos dos diferentes protocolos de treinamento de força (frequência, duração e intensidade) sobre parâmetros influenciadores da sarcopenia. MÉTODOS: Trata-se de uma revisão sistemática de estudos originais, quantitativos, observacionais, publicados entre 2010 a 2020, em inglês, espanhol e português, e indexados nas bases de dados SciELO, PubMed e periódico CAPES. Os descritores utilizados foram: "força muscular" ("muscle strenght", "fuerza muscular"), "sarcopenia" ("sarcopenia"), "envelhecimento" ("aging", "envejecimiento"), "idosos" ("olders, "ancianos"), "treinamento de força/resistência" ("strength training", "entrenamiento de fuerza"). Foram recuperados 215 artigos, entre eles 11 atenderam aos critérios de inclusão, sendo incluídos na revisão. RESULTADOS: Dentre os 11 estudos analisados, observa-se que o treinamento de força aplicado em diferentes protocolos foi eficiente em aperfeiçoar parâmetros como massa e força musculares, equilíbrio corporal e desempenho em testes diagnósticos de sarcopenia. CONCLUSÃO: Esta revisão evidencia os benefícios da prática de exercício de força em diferentes protocolos sobre parâmetros que influenciam na instalação do quadro de sarcopenia em idosos. O exercício de força se apresenta como meio aplicável, prático e não farmacológico da prevenção de sarcopenia.

Functional and Psychological Changes after Exercise Training in Post-COVID-19 Patients Discharged from the Hospital: A PRISMA-Compliant Systematic Review.

Millions of people worldwide are infected with COVID-19, and COVID-19 survivors have been found to suffer from functional disabilities and mental disorders such as depression and anxiety. This is a matter of concern because COVID-19 is still not over. Because reinfection is still possible in COVID-19 survivors, decreased physical function and increased stress and anxiety can lower immune function. However, the optimal exercise intensity and volume appear to remain unknown. Therefore, the current systematic review aimed to evaluate the effect of resistance or aerobic exercises in post-COVID-19 patients after hospital discharge. We conducted searches in the Scopus, SciELO, PubMed, Web of Science, Science Direct, and Google Scholar databases. Studies that met the following criteria were included: (i) English language, (ii) patients with COVID-19 involved with resistance or aerobic exercise programs after hospital discharge. Out of 381 studies reviewed, seven studies met the inclusion criteria. Evidence shows that exercise programs composed of resistance exercise (e.g., 1-2 sets of 8-10 repetitions at 30-80% of 1RM) along with aerobic exercise (e.g., 5 to 30 min at moderate intensity) may improve the functional capacity and quality of life (reduce stress and mental disorders) in post-COVID-19 patients. In addition, only one study reported reinfection of three subjects involved with the exercise program, suggesting that exercise programs may be feasible for the rehabilitation of the patients. A meta-analysis was not conducted because the included studies have methodological heterogeneities, and they did not examine a control group. Consequently, the results should be generalized with caution.

Polymorphism of the angiotensin converting enzyme gene (ACE-I/D) differentiates the aerobic and speed performance of football players.

BACKGROUND: The aim of this study was to evaluate the distribution of ACE-I/D polymorphisms on Brazilian football players performance in aerobic capacity, strength and speed tests. METHODS: The participants in this study were 212 Brazilian first division male football players genotyped in DD, ID or II. Genotyping of DNA from leucocytes was performed using polymerase chain reaction and restriction fragment length polymorphism methods. We evaluated speed using a 30-meter sprint test with speed measured at 10 meters (V10), 20 meters (V20), and 30 meters (V30); muscular strength using counter-movement-jump and squat jump tests; and aerobic endurance using the Yo-Yo endurance test. The athletes were ranked in ascending order according to their performance in each test and divided into quartiles: first quartile (0-25%, weak), second (25-50%, normal), third (50-75%, good), and fourth (75-100%, excellent); these were clustered according to genotype frequency. RESULTS: We identified significant differences in the V20 test values and in the aerobic capacity test. Higher frequencies of the ACE-DD genotype were observed in the excellent performance group in the V20. In the aerobic capacity test, higher frequencies of the ACE-II genotype were observed in excellent and good performance groups. CONCLUSIONS: Players with higher performance in anaerobic and aerobic tests are ACE-DD and ACE-II genotypes, respectively.

Effects of myofascial release of the ankle plantar flexors on static postural balance of young men: A randomized clinical trial.

BACKGROUND: Myofascial release (MR) has been widely used in sports and clinical environment. There are studies that have already evaluated the effect of MR on postural control, however, the data found are inconclusive. OBJECTIVES: Investigate the effect of MR on ankle plantar flexor muscles over static postural balance. METHOD: Sixty-five young men were randomized allocated into one of three groups: 1) MR group (n = 25, Myofascial Release); 2) Sham (n = 25, fake intervention); or 3) Control group (n = 15). Both MR and Sham techniques were applied during 5 min in the ankle flexors of each leg. The bipodal static postural balance test was performed before and 2 min post each intervention on a force plate with eyes closed during the test. All subjects performed 3 sets of 30-s with 1 min of rest. Mean values to the center of pressure velocity (COPvel) was used for analysis. RESULTS: The bipodal balance test showed that there was no significant difference between groups (p > 0.05), but there was a significant time effect (p < 0.05). A significant decrease (p < 0.05) in post-test COPvel (cm.s-1) values (sham 4.9 ± 1.2; MR 4.5 ± 0.6; CON 4.22 ± 0.8) was found when compared to values of pre-test (sham 5.3 ± 1.0; MR 5.0 ± 0.8; CON 4.94 ± 1.3) for all groups. CONCLUSIONS: The results demonstrated that MR performed on ankle flexors did not affect static postural balance in young man. This study is a clinical trial (Register Number: RBR-48k5jm).

Head pre-cooling improves 5-km time-trial performance in male amateur runners in the heat.

This study aimed to evaluate the effect of head pre-cooling on the 5-km time-trial performance of amateur runners in the heat. In a counterbalanced design, 15 male amateur runners (22.6 ± 3.5 y; VO2 max in heat 42.3 ± 4.4 mLO2 /kg/min) completed two 5-km time trials performed in the heat (35°C, 50% relative humidity). In one trial (HCOOL), participants underwent 20 min of head cooling in a temperate environment (23°C, 70% relative humidity) prior to exercise. In another trial (CON), exercise was preceded by 20 min of rest under the same temperature conditions. Exercise time was shorter in HCOOL (25 min and 36 s ± 3 min) compared to CON (27 ± 3 min; p = 0.02). Rectal temperature was reduced during the pre-exercise intervention in HCOOL (p < 0.001), but not in CON (p = 0.55). Relative changes in rectal temperature and mean head temperature were lower throughout HCOOL when compared with CON condition (p = 0.005 and p = 0.022, respectively). Mean skin temperature, heart rate, and rating of perceived exertion did not differ between HCOOL and CON conditions throughout exercise (p = 0.20, p = 0.52 and 0.31, respectively). Thermal comfort was lower in HCOOL condition in pre-exercise (p = 0.014) with no differences observed throughout exercise (p = 0.61). 5-km running performance in a hot environment was improved after a 20-min head cooling intervention, suggesting that this method may be practical as pre-cooling strategy and easily administered to both professional and amateur runners alike.

Resistance Training, Fatigue, Quality of Life, Anxiety in Breast Cancer Survivors.

ABSTRACT: Moraes, RF, Ferreira-Júnior, JB, Marques, VA, Vieira, A, Lira, CAB, Campos, MH, Freitas-Junior, R, Rahal, RMS, Gentil, P, and Vieira, CA. Resistance training, fatigue, quality of life, anxiety in breast cancer survivors. J Strength Cond Res 35(5): 1350-1356, 2021-Resistance training (RT) has shown to be effective in improving fatigue, quality of life (QOL), and anxiety levels among breast cancer survivors (BCS), but there is no consensus as to how this practice should be prescribed for optimal performance. This study analyses the effects of once weekly RT on fatigue, QOL, and anxiety levels among BCS. Randomized controlled trial. Twenty-five BCS (aged 54.6 ± 5.5 years) were randomized into RT or control groups. The RT group performed 8 weeks of RT (once per week). Fatigue was assessed using the Piper Fatigue scale, QOL was assessed using the SF-36, and anxiety was assessed using the STAI State-Trait Anxiety Inventory. Resistance training significantly improved the following subscales of SF-36: aspects of physical functioning (+27%, p = 0.027); physical role functioning (+54%, p = 0.008); emotional role functioning (+42%, p = 0.027); and mental health (+16%, p = 0.032). Furthermore, RT improved fatigue levels (-55%, p = 0.001 for general fatigue) and anxiety (anxiety state, -19%, p = 0.012; anxiety trait, -23%, p = 0.001). Resistance training seemed to be a positive nonpharmacological tool for the reduction of fatigue, anxiety, and for improvement of several aspects of QOL in BCS.

Treinamento pliométrico de membros superiores e inferiores em 5 semanas melhora desempenho físico de estudantes de educação física / Pliometric training in 5 weeks improves physical performance of physical education students: a pilot study

: Este estudo investigou o impacto de 5 semanas de treinamento pliométrico em membros superiores e inferiores sobre o desempenho físico em estudantes de Educação Física. Foram recrutados 16 estudantes do sexo masculino de 18 a 23 anos divididos em 2 grupos (Controle e Treino). O grupo Treino foi submetido ao treinamento pliométrico de membros superiores e inferiores por 5 semanas com 3 sessões/semana de 30-40 minutos/sessão, composta de 10 exercícios de braço e perna (10-20 repetições/exercício). Antes e imediatamente após o programa de treinamento pliométrico, os indivíduos foram avaliados por parâmetros antropométricos (peso, estatura, índice de massa corporal e percentual de gordura), nível de flexibilidade e desempenho físico (forças de toque e de ataque, salto vertical, sprint de 20 m e agilidade). Dados de flexibilidade e desempenho físico foram avaliados por análise de covariância (ANCOVA), além da correlação de Pearson entre as variáveis de desempenho físico após 5 semanas de treinamento. O grupo Treino exibiu maior ganho de desempenho no salto vertical quando comparado ao grupo Controle (p< 0,05). Todavia, não foi observada diferença significativa entre os grupos Treino e Controle nos ganhos de força de toque e de ataque, no desempenho do teste de sprint de 20 m, no teste de agilidade e de flexibilidade (p> 0,05). Houve correlação positiva entre os testes de forças de toque e de ataque com o salto vertical (p< 0,001, r= 0,633; e p< 0,001, r= 0,639; respectivamente), como também correlação dos testes salto vertical com os testes de velocidade (p< 0,001, r= -0,768) e agilidade (p< 0,002, r= -0,537) após o treinamento. Conclui-se que 5 semanas de treinamento pliométrico de membros superiores e inferiores exibiram melhora no desempenho do salto vertical de estudantes de Educação Física, bem como observou-se correlação entre os parâmetros neuromusculares anaeróbicos de membros inferiores e superiores após o período de treinamento.(AU)

This study investigated the impact of 5 weeks of plyometric training on upper and lower limbs on physical performance parameters in Physical Education students. Sixteen male college students aged 18 to 23 years were divided into 2 groups (Control and Training). The Training group was submitted to 5 weeks of plyometric training for upper and lower limbs, with 3 sessions per week for 30-40 minutes per session. Training sessions consisted of 10 arm and leg exercises (10-20 repetitions per exercise). Anthropometric parameters (weight, height, body mass index and body fat percentage), level of flexibility and physical performance (touch and attack strength, vertical jump, 20m sprint, agility) were assessed before and immediately after the plyometric training program. Flexibility and physical performance data were assessed by covariance analysis (ANCOVA), in addition to Pearson's correlation among physical performance parameters after 5 weeks of training. The Training group showed a greater gain in the vertical jump performance when compared to the Control group. However, no significant difference was observed between the Training and Control groups for touch and attack strength gains, for 20 m sprint performance gains, and for agility and flexibility test gains. There was a positive correlation between the tests of touch and attack strengths with vertical jump performance. There was also positive correlation between touch and attack strength with vertical jump (p< 0.001, r= 0.633; e p< 0,001, r= 0.639; respectively), and between vertical jump performance and 20m sprint performance (p< 0.001, r= -0,768) and agility test after training (p< 0.002, r= -0,537). It is concluded that 5 weeks of plyometric training for upper and lower limbs showed improvement in the vertical jump performance in Physical Education students. There was also a correlation between the anaerobic neuromuscular parameters of lower and upper limbs after the training period.(AU)

Is skin temperature associated with muscle recovery status following a single bout of leg press?

Objective. The measurement of skin temperature using infrared thermography has gained a lot of attention in sport and science since it might be related to the recovery process following high intensity, potentially damaging exercise. This study investigated the time course of the skin temperature response and the muscle recovery status following a resistance training session involving leg press exercise.Approach. Fourteen young male college students (19.9 ± 1.7 years, 176 ± 6 cm, 66.1 ± 7.6 kg, 21.1 ± 1.8 kg.m-2) performed one session involving 10 sets, of 10 repetition maximum each (RM), of unilateral leg press 45° exercise, performed to momentary muscle failure, with 2 min rest between sets. Perceived recovery, mean and maximum thigh skin temperatures, thigh muscle thickness, maximal isometric strength, muscle soreness, and horizontal jump performance were measured pre, 24, 48, and 72 h following exercise.Main results. The exercise protocol resulted in significant reduction in isometric strength, horizontal jump performance, and perceived recovery (p < 0.05). There was also a significant (p < 0.05) increase in muscle thickness and muscle soreness. With exception of jump performance, that recovered at 48 (p > 0.05), recovery parameters did not recover up to 72 h post-exercise (p > 0.05). Surprisingly, skin temperatures were not altered throughout the entire 72 h post-exercise period (p > 0.05). No significant positive correlation was found between skin temperatures and muscle thickness. Additionally, only one out of 16 correlation coefficients showed significant (r = -0.56,p = 0.036) inverse association between skin temperature and isometric strength.Significance. In conclusion, thigh skin temperature remains unaffected up to 72 h following a leg press exercise, and the time course response of thigh skin temperature was not associated with recovery status.

Effects of Static and Dynamic Stretching Performed Before Resistance Training on Muscle Adaptations in Untrained Men.

ABSTRACT: Ferreira-Júnior, JB, Benine, RPC, Chaves, SFN, Borba, DA, Martins-Costa, HC, Freitas, EDS, Bemben, MG, Vieira, CA, and Bottaro, M. Effects of static and dynamic stretching performed before resistance training on muscle adaptations in untrained men. J Strength Cond Res 35(11): 3050-3055, 2021-This study evaluated the effects of dynamic and static stretching (SS) performed before resistance training on biceps femoris hypertrophy and knee flexor strength gains in untrained young men. Forty-five untrained young men (age, 21.2 ± 0.5 years; mass, 72.2 ± 5.6 kg; height, 178 ± 1 cm) were randomly assigned to 1 of the 3 groups: (a) 80 seconds of SS (n = 14); (b) 80 seconds of dynamic stretching (DS, n = 13); or (c) control group (CON, n = 18) in which subjects performed no stretching before exercise. Both SS and DS were performed before resistance exercise. Resistance training consisted of 4 sets of 8-12 repetition maximum of seated leg curl exercise 2 days per week for 8 weeks, with a period of at least 48 hours between sessions. Unilateral biceps femoris muscle thickness (MT) and maximal isometric strength (MIS) of the knee flexors were measured 1 week before training and 1 week after the last training session. There were significant increases in MIS (SS = 13.9 ± 10.3 kgf; DS = 10.2 ± 13.1 kgf; CON = 12.7 ± 7.6 kgf; p < 0.05) and MT (SS = 6.0 ± 3.5 mm; DS = 6.7 ± 4.1 mm; CON = 5.7 ± 3.0 mm; p < 0.05) with no significant differences across groups (p > 0.05). Additionally, all groups demonstrated moderate effect sizes for MIS (1.27-1.4), and DS was the only group that had a large effect size for MT increases (DS = 2.18; SS = 1.35; CON = 0.92). In conclusion, 80 seconds of SS and DS did not induce any additional muscular adaptations to resistance training in untrained young men.

Effects of cumulative school soccer matches separated by 24-h or 48-h intervals on physical recovery status of U-19 players / Efeitos de partidas consecutivas de futebol escolar com intervalos de 24 e 48 horas no estado de recuperação física de jogadores Sub-19

Abstract This study aimed to evaluate the effects of cumulative school soccer matches separated by 24-h or 48-h intervals on the recovery status of U-19 players. Thirty-four school athletes (17.6 ± 1.1 years) who played in an U-19 school soccer competition (composed of one group with four teams and another group with three teams, followed by semifinals and final) were examined before three matches, which lasted 70 min. Seventeen athletes had a 24-h rest interval between each match (GGG group), while 18 athletes had a 48-h rest interval between the second and third matches (GG48hG group). Total Quality Recovery, countermovement jump, 10-m sprint, and maximum lumbar isometric strength were measured. The internal load of each match was calculated by the product of the session Rating of Perceived Exertion and match time. There was a 22% reduction in Total Quality Recovery (p< 0.001) and 12% in 10-m sprint performance (p< 0.001) before the third match in the GGG group, while the GG48hG group showed no changes for the same variables (p> 0.05). The countermovement jump decreased before the second match in both groups (GGG= 12% and GG48hG= 10%; p< 0.001), with no difference between groups (p> 0.05). In addition, both groups showed no changes in the isometric strength or the internal load match over the games (p> 0.05). Despite not providing complete muscle recovery, a 48-h interval between the second and third matches seems to have minimized the reduction of muscle performance due to consecutive matches.

Resumo Este estudo teve como objetivo avaliar os efeitos de partidas consecutivas de futebol escolar com intervalos de 24 e 48 horas no estado de recuperação física de jogadores Sub-19. Foram avaliados 35 homens (17,6±1,1 anos) atletas escolares sub-19. Durante a competição, foram realizados três jogos de 70-min de duração. Dezessete atletas tiveram intervalo de 24h entre cada jogo (grupo GGG). Dezoito atletas tiveram intervalo de 48 h entre o 2º e o 3º jogo (grupo GG48hG). Antes de cada jogo foram medidas a Qualidade Total de Recuperação, altura do salto com contra movimento, velocidade no sprint de 10-m, e força máxima isométrica lombar máxima. A carga interna do jogo foi calculada pelo produto da percepção subjetiva do esforço da sessão e tempo de cada jogo. Houve uma redução de 22% na qualidade total de recuperação (p <0,001) e de 12% no desempenho de sprint de 10 m (p <0,001) antes da terceira partida no grupo GGG, enquanto o grupo GG48hG não apresentou alterações para as mesmas variáveis (p> 0,05). O salto com contra movimento diminuiu antes da segunda partida em ambos os grupos (GGG = 12% e GG48hG = 10%; p <0,001), sem diferença entre os grupos (p> 0,05). Em adição, ambos os grupos não apresentaram alterações na força isométrica e na carga interna ao longo dos jogos (p> 0,05). Apesar de não proporcionar uma completa recuperação muscular, 48 h de intervalo entre o segundo e o terceiro jogo parece ter minimizado o efeito de jogos consecutivos na redução do desempenho.

The sex differences in the 10,000 m race strategy

Abstract Aim: This study aimed to compare the running strategy between men and women in the 10,000 m race. Methods: Data from one-hundred and twenty-nine athletes who competed the 10,000 m final of the 2015, 2017 and 2019 world championship were grouped according to gender: 1) male group (n= 63; age= 25.9±4.4), and 2) female group (n= 66; age= 27.3±4.8). The running strategy was determined by assessing velocity over each kilometer. The velocity was calculated from the times available on the official website of the International Athletics Federation. Results: Men decreased running velocity after the first kilometer and kept the speed stable until km 9 and the kilometer 10 was greater when compared with 6-9 kilometer, while women increase running velocity until km 2 and kept the speed stable until km 9. The kilometer 10 velocity was greater when compared with 1-9 kilometer. (p< 0.001). In addition, women showed a greater average velocity variation when compared to men (p< 0.001). Conclusion: Our findings show a sex differences in the 10,000 m race strategy between world-class.

Exercise: A Protective Measure or an "Open Window" for COVID-19? A Mini Review.

The coronavirus disease 2019 (COVID-19) has spread to at least 115 countries and caused an alarming number of deaths. The current outbreak has lead authorities from many countries to adopt several protective measures, including lockdown and social distancing. Although being a reasonable measure to counteract the COVID-19 contamination, the restrictive measures have limited individual's ability to perform exercise outdoors or in gyms and similar facilities, thus raising the risks for chronic health conditions related to a sedentary lifestyle. The recent exercise recommendations to counteract the potential deleterious effects of COVID-19-related lockdown have not fully addressed resistance exercise interventions as potential home-based exercise strategies. Additionally, the following questions have been constantly raised: (1) Is training status capable of protecting an individual from COVID-19 infection?; and (2) Can a single endurance or resistance exercise session acutely increase the risks for COVID-19 infection? Therefore, the current mini review aimed to focus on these two concerns, as well as to discuss the potential use of practical blood flow restriction and no load resistance training as possible resistance exercise strategies that could be performed during the current COVID-19 pandemic.

Corrigendum: Exercise: A Protective Measure or an "Open Window" for COVID-19? A Mini Review.

[This corrects the article DOI: 10.3389/fspor.2020.00061.].

Effects of Chemotherapy Treatment on Muscle Strength, Quality of Life, Fatigue, and Anxiety in Women with Breast Cancer.

The study aimed to evaluate the effects of chemotherapy treatment on muscle strength, quality of life, fatigue, and anxiety in women with breast cancer. Nineteen women who were undergoing a chemotherapy treatment (breast cancer treatment [BCT] group, 52.2 ± 13.1 years) and 18 women without cancer (control [CNT] group, 55.8 ± 8.4 years) answered questionnaires for evaluation of fatigue (Fatigue Scale), quality of life (Short-Form Healthy Survey [SF-36] questionnaire), and anxiety (State-Trait Anxiety Inventory [IDATE]) levels. Muscle strength was also assessed by an isometric grip test and an isokinetic knee extension test. Physical limitations, social and emotional domains of quality of life were lower in the BCT group in comparison to the CNT group (p = 0.002; p = 0.003; p = 0.0003, respectively). The other domains did not differ between groups (p > 0.05). There were no differences in fatigue and anxiety levels between both the BCT and CNT groups (p > 0.05). Additionally, isometric grip strength was higher in the CNT group when compared to the BCT group (p = 0.048). However, there were no differences between the BCT and CNT groups for peak torque and total work at both 60°.s-1 (p = 0.95 and p = 0.61, respectively) and 180°.s-1 (p = 0.94 and p = 0.72, respectively). These results suggest that three cycles of chemotherapy treatment may impair handgrip isometric strength and quality of life in women with breast cancer.

Effects of Horizontal and Incline Bench Press on Neuromuscular Adaptations in Untrained Young Men.

The aim of the current study was to investigate the effects of horizontal and incline bench press as well as the combination of both exercises on neuromuscular adaptation in untrained young men. Forty-seven untrained men were randomly assigned to one of the three groups: 1) a horizontal bench press group (n= 15), 2) an incline bench press group (n= 15), and 3) a combination (horizontal + incline) group (n= 17). Training was conducted once a week for eight weeks, with equalized number of sets among groups. Muscle thickness, isometric strength and electromyography (EMG) amplitude of the pectoralis major were measured one week before and after the training period. There was no difference between groups for the change in horizontal bench press isometric strength (~ 10 kg increase, p=0.776) or incline bench press isometric strength (~ 11 kg increase, p=0.333). Changes in muscle thickness differed only in one of the three sites. The changes in the second intercostal space of the pectoralis major was greatest in the incline pressure group compared with the horizontal [mean difference (95% CI) of 0.62 (0.23, 1.0) cm, p=0.003] and combination groups [mean difference (95% CI) of 0.50 (0.14, 0.86) cm, p=0.008]. The change in EMG amplitude following training differed between groups in only one out of the four sites. The present results indicate that strength and conditioning professionals might consider that horizontal and incline bench press exercises, or a combination of both exercises can render similar change in general strength.