Do Men and Women Differ in Hematological Adaptations to 24 Weeks of Crossfit® Training?

Regular exercise can modulate the immune system functioning through changes in the number and function of leukocytes as well as in red blood cells and other typical blood markers. High intensity exercise promotes increases in cytotoxic activity, phagocytic capacity, chemotaxis and cell apoptosis. The aim of the study was to compare the chronic effects of a 24-week training program using CrossFit® methodology on hematological variables of men vs. women. Twenty-nine CrossFit® athletes (35.3 ± 10.4 years, 175.0 ± 9.2 cm, 79.5 ± 16.4 kg) participated in the study. The blood count, the lipid profile and glucose markers were measured every two months during the study period. The erythrocyte count and hemoglobin concentrations increased in months 4 and 6 in men and women, respectively. Hematocrit levels increased in men in months 2, 4 and 6, while in women only in month 6. Red cell distribution width increased in men in month 6 when compared to the value in month 2. Segmented neutrophils increased in men in month 6 and eosinophil levels increased in women in month 6. Differences between the two sexes were observed in monocytes levels at baseline, as well as in months 2, 4 and 6. Cross-Fit® training increased red cell count indicators in both sexes, which may be related to increased erythropoiesis. Some white blood cell counts were altered and these differed between sexes. The number of lymphocytes remained stable throughout the experiment.

Exercise prevents obesity by reducing gut-derived inflammatory signals to brown adipocytes in mice.

Gut dysbiosis impairs nonshivering thermogenesis (NST) in obesity. The antiobesogenic effects of exercise training might involve the modulation of gut microbiota and its inflammatory signals to the brown adipose tissue (BAT). This study evaluated whether high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) prevent overweight through reduced gut-derived inflammatory signals to BAT in high-fat-fed mice. Sixty male C57BL/6 mice (3 months old) comprised six experimental groups: control (C) diet group, C diet + HIIT (C-HIIT) group, C diet + MICT (C-MICT) group, high-fat (HF) diet group, HF diet + HIIT (HF-HIIT) group, and HF diet + MICT (HF-MICT) group. The protocols lasted for 10 weeks. HIIT and MICT restored body mass, mitigated glucose intolerance, and prevented hyperinsulinemia in HF-trained groups. A chronic HF diet caused dysbiosis, but HIIT and MICT prevented gut dysbiosis and preserved tight junction (TJ) gene expression. HF-HIIT and HF-MICT groups exhibited a similar pattern of goblet cell distribution, agreeing with the decreased plasma lipopolysaccharide concentrations and interscapular BAT (iBAT) Lbp-Cd14-Tlr4 expression. The lowered Nlrp3 and Il1ß in the HF-HITT and HF-MICT groups complied with iBAT thermogenic capacity maintenance. This study shows reliable evidence that HIIT and MICT prevented overweight by restoring the diversity of the gut microbiota phyla and TJ gene expression, thereby reducing inflammatory signals to brown adipocytes with preserved thermogenic capacity. Both exercise modalities prevented overweight, but HIIT rescued Zo-1 and Jam-a gene expression, exerting more potent anti-inflammatory effects than MICT (reduced LPS concentrations), providing a sustained increase in thermogenesis with 78% less distance traveled.

Effects of Resistance Training in Individuals with Lower Limb Amputation: A Systematic Review.

Individuals with lower-limb amputations may have a significant strength deficit. This deficit may be related to the stump length and can lead to changes in gait, reduced energy efficiency, walking resistance, altered joint load, and increased risk of osteoarthritis and chronic low back pain. This systematic review used the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) guidelines to examine the effects of resistance training in lower limb amputees. Interventions with resistance training and other training methods were sufficient to achieve muscle strength gain in muscles of the lower limbs, improved balance, and improvements in gait pattern and speed when walking. However, it was impossible to determine from the results whether resistance training was mainly responsible for these benefits or even whether the positive effects presented would be observed with only this training method. When combined with other exercises, interventions with resistance training made possible gains for this population. Accordingly, it is noteworthy that the main finding of this systematic review is that the effects may be different according to the level of amputation, with mainly transtibial and transfemoral amputations studied.

Analysis of physiological markers and risk factors for the development of rhabdomyolysis in military personnel: a systematic review.

OBJECTIVES: To analyze case reports with individual patient data belonging to the Armed Forces submitted to specific physical or military combat training that was affected by rhabdomyolysis and identify factors that influenced the diagnosis and clinical evolution of the syndrome. CONTENT: We conducted a systematic review following the PRISMA guidelines and registered on PROSPERO (CRD42021242465). We searched MedLine (via PubMed), Scopus, Cochrane, Lilacs, SciELO, CINAHL, Web of Science, SPORTDiscus, ScienceDirect, and PEDro databases for studies that reported cases of military personnel affected by rhabdomyolysis. SUMMARY AND OUTLOOK: Thirteen studies met the inclusion criteria. Forty-nine individual cases of rhabdomyolysis were analyzed. From them, it was possible to identify several associated factors, which were responsible for developing rhabdomyolysis in military personnel. Thirty military personnel (60%) practiced physical training and 20 (40%) practiced specific military combat training. The creatine kinase (CK) peak ranged from 1,040 to 410,755 U/L, with an average of 44.991 U/L, and 14 (28%) of the cases reported alteration of renal function and four militaries (8%) evolved to death condition. Physical activities performed strenuously and without proper planning conditions such as room temperature, the period without adequate water intake, the amount of equipment used during the activity contributed to the development of rhabdomyolysis in the cases of military personnel analyzed in the present study. Therefore, it is recommended that future studies investigate the relationship between the prevalence of rhabdomyolysis cases and the severity of its consequence when associated with progressive methods of training, hydration control, acclimatization to austere environments, monitoring for the existence of hereditary diseases, and control of the use of supplementary nutritional substances.

Evaluation methods and objectives for neuromuscular and hemodynamic responses subsequent to different rest intervals in resistance training: a systematic review / Métodos de evaluación y objetivos para las respuestas neuromusculares y hemodinámicas posteriores a diferentes intervalos de descanso en el entrenamiento de resistencia: una revisión sistemática

Introduction: The training routine planned, and performed correctly results in exercises that, systematically organized,influence the levels of strength, and muscle hypertrophy. However, the magnitudes of these gains vary considerably. Tooptimize these gains, it is important to underst, and the interaction between training variables such as external load, volume,number of exercises, number of repetitions, duration of repetitions, the order of exercises, number of series, recovery intervalbetween series, and the exercises, as well as the time under tension. The influence of the recovery interval on the responsefollowing exercise on neuromuscular components is very important. However, different objectives, and instruments are usedto evaluate these responses.Objective: The purpose of this study is to conduct a systematic review of the assessment methods, and objectives for respon-ses after different recovery intervals in strength training. METHODS: The present study is characterized by a systematic reviewstudy. Articles found in the following databases were considered for the systematic review: Scopus, PubMed / MEDLINE, Webof Science, Cochrane Library. The following descriptors, and their respective synonyms according to the terms MeSH wereused in the databases, both singular, and plural: “Resistance Training”, “Rest Interval”, and “Bech Press”. As filters were used: a)species (humans), and type of study (original).Results: Seven studies were analyzed that met the established criteria.Conclusion: The studies presented have verified the influence of different recovery intervals on muscle, and hemodynamicresponses. Evaluating image measurements such as ultrasound, and resonance, blood measurements such as GH, Testosterone,IGF-1, and Lactate, number of repetitions for performance, and fatigue, as well as heart rate, and blood pressure.(AU)

Introducción: La rutina de entrenamiento planificada y realizada correctamente da como resultado ejercicios que, organizadossistemáticamente, influyen en los niveles de fuerza e hipertrofia muscular. Sin embargo, las magnitudes de estas gananciasvarían considerablemente. Para optimizar estas ganancias, es importante comprender la interacción entre las variables deentrenamiento como la carga externa, el volumen, el número de ejercicios, el número de repeticiones, la duración de lasrepeticiones, el orden de los ejercicios, el número de series, el intervalo de recuperación entre series y los ejercicios, así comoel tiempo bajo tensión. La influencia del intervalo de recuperación en la respuesta después del ejercicio en los componentesneuromusculares es muy importante. Sin embargo, se utilizan diferentes objetivos e instrumentos para evaluar estas respuestas.Objetivo: El propósito de este estudio es realizar una revisión sistemática de los métodos y objetivos de evaluación paralas respuestas posteriores a los diferentes intervalos de recuperación en el entrenamiento de fuerza. MÉTODOS: El presenteestudio se caracteriza por un estudio de revisión sistemática. Los artículos encontrados en las siguientes bases de datos seconsideraron para la revisión sistemática: Scopus, PubMed / MEDLINE, Web of Science, Cochrane Library. Los siguientes des-criptores y sus respectivos sinónimos según los términos MeSH se utilizaron en las bases de datos, tanto en singular como enplural: “Entrenamiento de resistencia”, “Intervalo de descanso” y “Bench Press”. Como filtros se utilizaron: a) especies (humanos)y tipo de estudio (original).Resultados: Se analizaron siete estudios que cumplieron con los criterios establecidos.Conclusión: Los estudios presentados han verificado la influencia de diferentes intervalos de recuperación en las respuestasmusculares y hemodinámicas. Evaluación de mediciones de imagen como ultrasonido y resonancia...(AU)

Acute high-intensity exercise test in soccer athletes affects salivary biochemical markers.

Saliva has been reported as a potential biological fluid for biochemical monitoring. This study investigated salivary markers of exercise intensity, oral mucosal immunity, and redox homeostasis in soccer athletes subjected to an acute high-intensity interval exercise (HIIE) protocol characterised by a repeated sprint ability test. Thirty-two professional soccer athletes were recruited and saliva aliquots were collected at rest and immediately after HIIE protocol. When compared with pre-test values we observed that HIIE protocol induced moderate changes for total protein (p = .015; effect size (ES) = 0.51; smallest worthwhile change (SWC)factor = 5.7) and for cortisol levels (p < .0001; ES = 0.49; SWCfactor = 3.9). Lactate levels showed very large changes (p < .000; ES = 1.35; SWCfactor = 10.8), while Ig-A alterations were considered unclear. Besides, transferrin changes were trivial and maintained its levels at rest and after HIIE below the proposed threshold of 0.5 mg/dL. Regarding redox homeostasis we observed unclear effects for TBARs, MDA, GSH, GSSG, CAT, and SOD while uric acid showed large decreases (p = .005; ES = 0.80; SWCfactor = -5.4). HIIE protocol as a physical test conducted in soccer athletes increased salivary concentration of exercise intensity markers, such as lactate, total protein, and cortisol, but did not affect Ig-A levels. Redox homeostasis in saliva seems to be more related with uric acid levels as a possible key factor TBARs homeostasis.

Biological maturation assessment methods in adolescent soccer players considering zinc status / Métodos de evaluación de la maduración biológica en jugadores adolescentes de fútbol considerando el estado de zinc

SUMMARY: The purpose of this study was to compare different methods of maturity evaluation and their relation with performance-related physical and anthropometric variables in young soccer players, with different plasma zinc status. A total of 53 healthy male young soccer players (age: 13±1 years; body mass: 48±10 kg; stature: 160±10 cm) participated in this study. Variables from physical fitness (stature, ST; fat-free mass, FFM; handgrip strength in the dominant hand, DHS), testosterone and zinc plasma concentration were measured. Biological maturity was evaluated by sexual maturity (development of: pubic hair, PH; genitals, GD; axillary hair; AH), bone maturity (TW3 method; BA), and testosterone plasma concentration methods. We observed that: (i) the frequency of hypozincemics and normozincemics children stratified by BA-CA, PH and GD were similar in each category; (ii) the BA allowed the identification of differences between the three categories, in at least two performance-related variables (FFM and DHS, p<0.0001); (iii) the AH method was able to discriminate only for DHS (p<0.0001); and (iv) the testosterone method was not able to identify differences between the four maturation categories with regard to ST, FFM, and DHS. Results suggested that Zinc deficiency did not influence the results obtained for the maturation categories defined by the different assessment methods. The assessment of biological maturation by BA seems to be the most effective for the stratification of performance-related and anthropometric variables in young soccer players. Nevertheless, the AH method should also be considered as a fair option to be used in field studies and practice.

RESUMEN: El objetivo de este estudio fue comparar diferentes métodos de evaluación de madurez y su relación con variables físicas y antropométricas relacionadas con el desempeño en jóvenes jugadores de fútbol, con diferentes niveles plasmáticos de zinc. Participaron en este estudio 53 jugadores de fútbol jóvenes sanos (edad: 13 ± 1 años, masa corporal: 48 ± 10 kg, estatura: 160 ± 10 cm). Se midieron las variables de la aptitud física (estatura, ST, masa libre de grasa, FFM, fuerza de agarre en la mano dominante, DHS), testosterona y concentración plasmática de zinc. Se evaluaron la madurez sexual (desarrollo de vello púbico, PH, genitales, DG, cabello axilar, AH), madurez ósea (método TW3, BA) y concentración plasmática de testosterona. Se observó que: (i) la frecuencia de los niños hipoxincémicos y normozincémicos estratificados por BA-CA, PH y GD fueron similares en cada categoría; (ii) el BA permitió la identificación de diferencias entre las tres categorías, en al menos dos variables relacionadas con el desempeño (FFM y DHS, p <0,0001); (iii) el método AH fue capaz de discriminar sólo para DHS (p <0,0001); y (iv) el método de testosterona no fue capaz de identificar diferencias entre las cuatro categorías de maduración con respecto a ST, FFM y DHS. Los resultados sugirieron que la deficiencia de zinc no influyó en los resultados obtenidos para las categorías de maduración definidas por los diferentes métodos de evaluación. La evaluación de la maduración biológica por BA parece ser la más efectiva para la estratificación de variables de rendimiento y antropométricas en jóvenes jugadores de fútbol. Sin embargo, el método AH también debe ser considerado como una opción justa para ser utilizado en estudios de campo y práctica.

Methodological agreement between body-composition methods in young soccer players stratified by zinc plasma levels / Acuerdo metodológico entre los métodos de composición corporal en jugadores jóvenes de fútbol estratificados por los niveles plasmáticos de zinc

It is feasible to think that the body composition assessment may be influenced by maturational and zinc status, especially in young athletes, which perform regularly high volume of physical training. In accordance, it seems important to clarify the impact of these factors in body composition assessment in athletes, since errors may lead to mistakes in training prescription and diet elaboration, and therefore affect the athletic performance. The objective was to compare (1) different methods of body composition evaluation in young soccer players stratified by zinc plasma levels; and (2) the two reference methods using skinfolds thickness in children (Slaughter's and Lohman's equations), considering the maturation level. In this cross-sectional study, fifty tree young soccer players (13.3±0.7 y) were submitted to blood collection, electric bioimpedance (BIA), dual energy X-ray absorptiometry (DXA), anthropometric measures (body mass, stature and skinfolds thickness (ST)) and hand-wrist X-ray. Body composition evaluation was performed by: DXA, ST (Lohman and Slaughter equations) and BIA (Houtkooper equation) methods. Zinc status provided two groups: Normozincemic and Hypozincemic athletes, determined by cut-off point of 11.0 µmol/L. Significant difference on descriptive data for all participants after zinc status stratification was observed only for plasma zinc concentration; (2) Significant correlations were observed between the assessment methods (fat percentage: r= 0.34 to 0.98 and p<0.001 to 0.013; fat free mass: r= 0.95 to 0.9998 and p<0.001), and lowers correlations were observed when electric impedance was involved; and (3) Bland-Altman plots across methods showed a closer agreement when DXA and ST were compared. In conclusion (1) The ST method was better than BIA to assess the body composition (in young soccer players) when DXA scans are not available; (2) The comparison of models based on ST showed that the best association with the values from DXA were obtained for the Slaughter equation, followed by the Lohman equation using bone age instead of chronological age; and (3) Plasma zinc levels seem not to influence the body composition assessment, which certainly warrants further studies.

Es factible pensar que la evaluación de la composición corporal puede estar influenciada por el estado de maduración y los niveles plasmáticos de zinc, especialmente en atletas jóvenes, que regularmente realizan un alto volumen de entrenamiento físico. Por tanto, es importante aclarar el impacto de estos factores en la evaluación de la composición corporal de los atletas, ya que errores en su análisis pueden conducir al desarrollo de una equivocada prescripción de entrenamiento, además de una dieta determinada, y por lo tanto afectar el rendimiento deportivo. El objetivo de esta investigación consistió en: (1) comparar los diferentes métodos de evaluación de la composición corporal en futbolistas jóvenes estratificados por los niveles plasmáticos de zinc; (2) comparar los dos métodos de referencia utilizando el espesor de los pliegues cutáneos en niños (ecuaciones de Slaughter y Lohman), teniendo en cuenta el nivel de maduración. En este estudio transversal, cincuenta futbolistas jóvenes (13,3±0,7 años) fueron sometidos a un perfil bioquímico de sangre, bioimpedancia eléctrica (BIA), absorciometría de rayos X de energía dual (DXA), medidas antropométricas (masa corporal, estatura y pliegues cutáneos de espesor (ST)) y radiografía de mano-muñeca. La evaluación de la composición corporal se realizó por: DXA, ST (ecuaciones Lohman y Slaughter) y BIA (ecuación Houtkooper). El nivel de zinc identificó dos grupos: deportistas normozincémicos e hipozincémicos, determinados por un punto de corte de 11,0 mmol/L. Se observó una diferencia significativa en los datos descriptivos de todos los participantes después de la estratificación del estado de zinc sólo para la concentración de zinc en plasma; se observaron correlaciones significativas entre los métodos de evaluación (porcentaje de grasa: r= 0,34 a 0,98 y p <0,001 a 0,013; masa libre de grasa: r= desde 0,95 hasta 0,9998 y p <0,001), y disminuyeron las correlaciones al estar involucrada la impedancia eléctrica. Los resultados a través de los métodos Bland y Altman mostraron un acuerdo más cercano al comparar DXA y ST. El método ST fue mejor que el BIA para evaluar la composición corporal (en los jugadores jóvenes de fútbol), cuando no estaban disponibles los escaneos DXA. La comparación de los modelos basados en ST mostró que la mejor asociación de valores DXA se obtuvieron para la ecuación Slaughter, seguidos por la ecuación Lohman utilizando la edad ósea en lugar de la edad cronológica. Los niveles de zinc en plasma parecen no influir en la evaluación de la composición corporal, lo que amerita más estudios.

High Intensity Interval Training (HIIT) Induces Specific Changes in Respiration and Electron Leakage in the Mitochondria of Different Rat Skeletal Muscles.

High intensity interval training (HIIT) is characterized by vigorous exercise with short rest intervals. Hydrogen peroxide (H2O2) plays a key role in muscle adaptation. This study aimed to evaluate whether HIIT promotes similar H2O2 formation via O2 consumption (electron leakage) in three skeletal muscles with different twitch characteristics. Rats were assigned to two groups: sedentary (n=10) and HIIT (n=10, swimming training). We collected the tibialis anterior (TA-fast), gastrocnemius (GAST-fast/slow) and soleus (SOL-slow) muscles. The fibers were analyzed for mitochondrial respiration, H2O2 production and citrate synthase (CS) activity. A multi-substrate (glycerol phosphate (G3P), pyruvate, malate, glutamate and succinate) approach was used to analyze the mitochondria in permeabilized fibers. Compared to the control group, oxygen flow coupled to ATP synthesis, complex I and complex II was higher in the TA of the HIIT group by 1.5-, 3.0- and 2.7-fold, respectively. In contrast, oxygen consumed by mitochondrial glycerol phosphate dehydrogenase (mGPdH) was 30% lower. Surprisingly, the oxygen flow coupled to ATP synthesis was 42% lower after HIIT in the SOL. Moreover, oxygen flow coupled to ATP synthesis and complex II was higher by 1.4- and 2.7-fold in the GAST of the HIIT group. After HIIT, CS activity increased 1.3-fold in the TA, and H2O2 production was 1.3-fold higher in the TA at sites containing mGPdH. No significant differences in H2O2 production were detected in the SOL. Surprisingly, HIIT increased H2O2 production in the GAST via complex II, phosphorylation, oligomycin and antimycin by 1.6-, 1.8-, 2.2-, and 2.2-fold, respectively. Electron leakage was 3.3-fold higher in the TA with G3P and 1.8-fold higher in the GAST with multiple substrates. Unexpectedly, the HIIT protocol induced different respiration and electron leakage responses in different types of muscle.

Biomarkers of oxidative stress and tissue damage released by muscle and liver after a single bout of swimming exercise.

Both acute exercise and excessive training can cause oxidative stress. The resulting increase in free radicals and the inadequate response from antioxidant systems can lead to a framework of cellular damage. An association between affected tissue and the biomarkers of oxidative stress that appear in plasma has not been clearly established. The aim of this study was to evaluate the source of oxidative stress biomarkers found in the plasma of untrained rats after a single bout of swimming exercise at 2 different intensities: low intensity (SBLIE) or high intensity (SBHIE). Immediately after the exercise, aspartate transaminase (AST), alanine transaminase (ALT), γ-glutamyltransferase (GGT), and lactate dehydrogenase (LDH) were measured in plasma to characterize cell damage. Oxidative stress was assessed using protein carbonylation (PC), total antioxidant capacity (TAC), and thiobarbituric acid reactive substances (TBARS) quantified by malondialdehyde concentration. SBHIE raised levels of plasma AST (93%) and ALT (17%), and both exercise regimens produced an increase in GGT (7%) and LDH (∼55%). Plasma levels of PC and TBARS were greater in the SBHIE group; there were no changes in TAC. SBLIE caused only a modest increase in TBARS. In muscle, there were no changes in TAC, PC, or TBARS, regardless of exercise intensity, In the liver, TAC and TBARS increased significantly in both the SBLIE and SBHIE groups. This indicates that the oxidative stress biomarkers measured in the plasma immediately after a single bout of swimming exercise were generated primarily in the liver, not in muscle.

Redox balance and mitochondrial glycerol phosphate dehydrogenase activity in trained rats.

Free radical production is increased in many disease states and during exercise, but in the latter the concurrent stimulation of the antioxidant defense system seems to protect the organism from excessive production of reactive oxygen species. Chronic exercise can exert negative effects on the activity of mitochondrial glycerol phosphate dehydrogenase (mGPdH), which may offer some explanation for the antioxidant effects of training, since this enzyme is a relevant producer of free radicals. To test this correlation, we compared mGPdH activity, two antioxidant defense markers and two markers of oxidative stress in sedentary and trained (Tr) rats. Training was through a swimming exercise 3 days a week. After 8 weeks, Tr rats lasted twice as long as controls in an acute swimming test with a 5% load. Forty-eight hours after the last exercise, the animals were killed to collect blood and tissues. Tr animals presented lower body weight and visceral fat mass with lower triglyceride content in visceral fat and plasma (p < 0.05). The specific activity of mGPdH in muscle mitochondria was reduced in Tr rats by 88% (p < 0.05). Total antioxidant capacity, lipid peroxidation and reduced glutathione (GSH) in liver and muscle were unaltered, while plasma GSH increased by 21% (p < 0.05). These data suggest a profile of successful redox equilibrium maintenance in Tr rats, with a potentially significant contribution from the lower level of mGPdH activity in muscle. This training protocol appears to be suitable for use in detailed studies of biochemical adaptations to oxidative stress.

Análise do conhecimento de profissionais de Educação Física referente à prescrição de exercícios físicos para portadores de condromalácia patelar / Knowledge analysis of physical education professionals regarding exercise prescription for patients with chondromalacia patellae

Este trabalho buscou verificar a conduta profissional que professores de Educação Física (PEFs) possui na utilização do exercício de extensão de joelhos na cadeira extensora e no leg press em pessoas sofrendo de condromalácia da patela. Dois experimentos foram feitos, utilizando questionários aplicados em academias do Rio de Janeiro. O primeiro estudo foi dividido nas seguintes opções: “cadeira extensora”, “leg press”, “ambos” e “nenhum” e foi aplicado em 18 PEFs. O segundo estudo foi relacionado com a utilização de ângulos específicos na máquina de extensão de pernas que foi dividido em: “0°-30°”, “60°-90°”, “ambos” e “nenhum” que foi aplicado em 24 PEFs. Adicionalmente ambos os questionários possuíam seções específicas onde informação complementar poderia ser escrita para justificar as respostas. As justificativas foram nomeadas (JT+) quando satisfatória e (JT-) na ausência de argumentos baseados em dados científicos. A análise estatística foi feita com o teste qui-quadrado e a significância foi considerada quando o valor de p era menor do que 0,05. No primeiro estudo nós observamos que a utilização do leg press foi menor do que as outras opções. Além disso, o percentual de JT+ foi maior nas opções “cadeira extensora”, “leg press” e “nenhum”. No segundo estudo nós observamos que o percentual de PEFs que escolheram a opção “0°-30°” foi maior em relação a opção “ambos”. Quando as justificativas foram analisadas, nós observamos que todas as opções tiveram um maior percentual de JT-, com exceção da opção “ambos” que não mostrou diferenças (p>0,05). Nós concluímos que os PEFs possuem uma adequada conduta quando escolhem os exercícios para pessoas com condromalácia patelar, porém existe uma necessidade de melhor sustentar as argumentações relacionadas com a utilização de ângulos no exercício de cadeira extensora.

This work aimed to verify which professional conduct Physical Education teachers (PETs) have when using knee extension exercise with leg extension machines and leg presses in people suffering from chondromalacia patellae. Two experiments were done using questionnaires applied in Rio de Janeiro gyms. The first study was divided in the following options: “leg extension”, “leg presses”, “both” or “none” and was applied in 18 PETs. The second study was related to the utilization of specific angles in leg extension machines that were divided in: “0°-30°”, “60°-90°”, “both” and “none” that was applied to 24 PETs. Additionally both questionnaires have specific sections where complementary information could be written to justify the answers. The explanations was named (JT+) when satisfactory and (JT-) in the absence of arguments based in scientific data. Statistical analysis was done by chi square test and significance was considered when p value was lower than 0.05. In first study we observed that leg press utilization was lower than the other options. Besides that JT+ percent was higher in options “leg extension”, “leg press” and “none” but had no significant alterations in “both”. In second study we observed that the percent of PETs that chose option “0-30°” was higher in relation to the option “both”. When the explanations were analyzed, we observed that all the options had a higher percentage of JT- with exception of option “both” that showed no differences (p>0.05). We conclude that PETs have an adequate conduct when choosing exercises for people with chondromalacia patellae, however there is a need to better sustain the argumentations relating to angle utilization in leg extension exercises.

Plasma zinc, copper, and serum thyroid hormones and insulin levels after zinc supplementation followed by placebo in competitive athletes.

Intense physical activity is associated with biological adaptations involving hormones and trace elements. Zinc supplementation may affect plasma copper concentration, thyroid-stimulating hormone (TSH), thyroid hormones, insulin, and glucose homeostasis, but data in athletes are scarce. The aim of this study was to evaluate in competitive athletes (cyclists, n = 7, 32 ± 8 years) the effect of zinc supplementation (22 mg/day as zinc gluconate) during 30 days, and discontinuation using placebo (maltodextrin) during the following 30 days, on plasma zinc and copper concentrations, serum thyroid hormones, insulin and glucose levels, and HOMA2-IR. Compared to baseline, plasma zinc and Zn:Cu plasma ratio increased, but plasma copper decreased after zinc supplementation (day 30) and discontinuation (day 60) (p < 0.05). Zn supplementation and discontinuation had no effect on TSH, T3, and T4. Fasting serum insulin and HOMA2-IR increased (27% and 47%, respectively) on day 60 compared to baseline (p = 0.03), suggesting a delayed effect of zinc supplementation. Moreover, plasma zinc was positively associated with serum insulin (r = 0.87, p = 0.009) and HOMA2-IR (r = 0.81, p = 0.03) after zinc supplementation (day 30), indicating that supplemental zinc may impair glucose utilization in cyclists.

Associations of n-6 and n-3 polyunsaturated fatty acids and tocopherols with proxies of membrane stability and subcutaneous fat sites in male elite swimmers.

We hypothesize that membrane stability of elite swimmers adapted to chronic intense training is dependent on polyunsaturated fatty acids (PUFAs) and tocopherols in blood pools and that the composition of PUFA in plasma nonesterified fatty acids (NEFAs) might be associated with specific subcutaneous fat sites. Our aims were to investigate in male elite swimmers the associations of n-6 and n-3 PUFA and alpha- and gamma-tocopherols with proxies of membrane stability (phase angle and erythrocyte osmotic fragility) and of PUFA in plasma NEFA with specific skinfolds. Brazilian male elite swimmers (n = 20) under regular training for an average of 4.1 h/d and 6.1 d/wk took part in the study. Blood samples were obtained once after 18-hour rest and an overnight fast. Fatty acids were determined in plasma NEFA and erythrocytes by gas chromatolography and tocopherols were determined in plasma and erythrocytes by high-performance liquid chromatography. The status of PUFA was assessed as mean melting point, PUFA index [(Sigman-6 + Sigman-3) / (Sigman-7 + Sigman-9)] and docosahexaenoic acid indices (22:5n-6/22:4n-6 and 22:6n-3/22:5n-6 ratios) calculated from erythrocyte fatty acids. Phase angle was associated with an index of docosahexaenoic acid inadequacy (22:5n-6/22:4n-6; r = -0.53, P = .019) and with 22:5n-3 in erythrocytes (r = 0.51, P = .024), and erythrocyte osmotic fragility was associated with plasma alpha-tocopherol (r = -0.51, P = .05), which is a biomarker of vitamin E status. Plasma NEFAs 18:3n-3 and 20:4n-6 were positively associated with skinfolds of the trunk and arms (r = 0.49-0.59, P = .011-.043). The data presented indicate that n-3 PUFA and vitamin E states possibly improve membrane stability in elite swimmers and that the extent of specific anatomic sites of subcutaneous adipose tissue in the upper body might contribute to the composition of NEFA in the resting state.

Myosin is reversibly inhibited by S-nitrosylation.

Nitric oxide (NO*) is synthesized in skeletal muscle and its production increases during contractile activity. Although myosin is the most abundant protein in muscle, it is not known whether myosin is a target of NO* or NO* derivatives. In the present study, we have shown that exercise increases protein S-nitrosylation in muscle, and, among contractile proteins, myosin is the principal target of exogenous SNOs (S-nitrosothiols) in both skinned skeletal muscle fibres and differentiated myotubes. The reaction of isolated myosin with S-nitrosoglutathione results in S-nitrosylation at multiple cysteine thiols and produces two populations of protein-bound SNOs with different stabilities. The less-stable population inhibits the physiological ATPase activity, without affecting the affinity of myosin for actin. However, myosin is neither inhibited nor S-nitrosylated by the NO* donor diethylamine NONOate, indicating a requirement for transnitrosylation between low-mass SNO and myosin cysteine thiols rather than a direct reaction of myosin with NO* or its auto-oxidation products. Interestingly, alkylation of the most reactive thiols of myosin by N-ethylmaleimide does not inhibit formation of a stable population of protein-SNOs, suggesting that these sites are located in less accessible regions of the protein than those that affect activity. The present study reveals a new link between exercise and S-nitrosylation of skeletal muscle contractile proteins that may be important under (patho)physiological conditions.

Plasma leptin, plasma zinc, and plasma copper are associated in elite female and male judo athletes.

The purpose of this study was to compare plasma leptin, plasma zinc, and plasma copper levels and their relationship in trained female and male judo athletes (n = 10 women; n = 8 men). Blood samples were obtained 24 h after training to measure plasma zinc, copper, and leptin levels. Subjects presented similar values to age (22 +/- 2 years old), body mass index (24 +/- 1 kg/m(2)), plasma zinc (17.2 +/- 2 micromol/L), copper (12.5 +/- 2 micromol/L), and leptin (5.6 +/- 1.3 microg/L). However, height, total body mass, lean mass, fat mass, and sum of ten-skinfold thickness were higher in male than female. Plasma leptin was associated with sum of ten skinfolds in male (r = 0.91; p < 0.001) and female athletes (r = 0.84; p < 0.003). Plasma zinc was associated with leptin in males (r = 0.82; p < 0.05) while copper was associated with plasma leptin in females (r = 0.66; p < 0.05). Our results suggest that young judo athletes lost sex-related differences in leptin levels. Plasma zinc, plasma copper, and energy homeostasis may be involved in regulation of plasma leptin.

Bone healing in rats submitted to weight-bearing and non-weight-bearing exercises.

BACKGROUND: To investigate the effects of low-intensity exercise on bone healing during a short time. MATERIAL/METHODS: We made a surgical 1-mm perforation in the upper third medial cortical of the right tibia of 45 male Wistar rats (3 months old; mean weight, 282+/-34 g). Animals were randomly assigned to a swimming exercise group (SWIM, n=15), a running exercise group (RUN, n=15), or a no exercise control group (CON, n=15). Treatment sessions (10 minutes/day, 5 days/week) were done for 7, 14, or 21 days. Tibias were removed for radiographic, morphometric, and stereologic analyses. Blood samples were obtained for biochemical analyses. RESULTS: Serum phosphorus levels were higher in animals in the RUN group compared with animals in the SWIM group on the seventh day. On the 14th day, the tibias of the animals in the SWIM and RUN groups exhibited higher radiopacity in radiographic grades than animals in the CON group. No difference in collagen morphometry was verified. On the 21st day, serum alkaline phosphatase levels were higher in animals in the CON group than they were in the exercise groups, and animals in the SWIM and CON groups demonstrated an increase in newly formed bone in comparison to animals in the RUN group. CONCLUSIONS: At the 14th day of treatment, weight-bearing exercise, assessed by radiography, was found to be beneficial for bone healing. Results at the 21st day of treatment further supported the benefits of non-weight-bearing exercises, showing that weight-bearing exercise may improve bone repair in rats.