Loss of strength capacity is associated with mortality, but resistance exercise training promotes only modest effects during cachexia progression.

AIMS: Resistance exercise training (RET) has been adopted as non-pharmacological anti-catabolic strategy. However, the role of RET to counteract cancer cachexia is still speculative. This study aimed to verify whether short-term RET would counteract skeletal muscle wasting in a severe cancer cachexia rat model. MAIN METHODS: Wistar rats were randomly allocated into four experimental groups; 1) untrained control rats (control), 2) rats submitted to RET (control+RET), 3) untrained rats injected with Walker 256 tumor cells in the bone marrow (tumor) and 4) rats injected with Walker 256 tumor cells in the bone marrow and submitted to RET (tumor+RET). KEY FINDINGS: Tumor group displayed skeletal muscle atrophy fifteen days post tumor cells injection as assessed by plantaris (-20.5%) and EDL (-20.0%) muscle mass. EDL atrophy was confirmed showing 43.8% decline in the fiber cross sectional area. Even though RET increased the lactate dehydrogenase protein content and fully restored phosphorylated form of 4EBP-1 to the control levels in skeletal muscle, it failed to rescue muscle morphology in tumor-bearing rats. Indeed, RET did not mitigated loss of muscle function, anorexia, tumor growth or mortality rate. However, loss of strength capacity (assessed by 1-RM test performance) demonstrated a negative correlation with rats' survival (p=0.02; r=0.40), suggesting that loss of strength capacity might predict cancer mortality. SIGNIFICANCE: These results demonstrated that bone marrow injection of Walker 256 tumor cells in rats induces cancer cachexia, strength capacity is associated with cancer survival and short-term RET promotes only modest effects during cachexia progression.

Development of a specific anaerobic field test for aerobic gymnastics.

The current investigation aimed to develop a valid specific field test to evaluate anaerobic physical performance in Aerobic Gymnastics athletes. We first designed the Specific Aerobic Gymnast Anaerobic Test (SAGAT), which included gymnastics-specific elements performed in maximal repeated sprint fashion, with a total duration of 80-90 s. In order to validate the SAGAT, three independent sub-studies were performed to evaluate the concurrent validity (Study I, n=8), the reliability (Study II, n=10) and the sensitivity (Study III, n=30) of the test in elite female athletes. In Study I, a positive correlation was shown between lower-body Wingate test and SAGAT performance (Mean power: p = 0.03, r = -0.69, CI: -0.94 to 0.03 and Peak power: p = 0.02, r = -0.72, CI: -0.95 to -0.04) and between upper-body Wingate test and SAGAT performance (Mean power: p = 0.03, r = -0.67, CI: -0.94 to 0.02 and Peak power: p = 0.03, r = -0.69, CI: -0.94 to 0.03). Additionally, plasma lactate was similarly increased in response to SAGAT (p = 0.002), lower-body Wingate Test (p = 0.021) and a simulated competition (p = 0.007). In Study II, no differences were found between the time to complete the SAGAT in repeated trials (p = 0.84; Cohen's d effect size = 0.09; ICC = 0.97, CI: 0.89 to 0.99; MDC95 = 0.12 s). Finally, in Study III the time to complete the SAGAT was significantly lower during the competition cycle when compared to the period before the preparatory cycle (p < 0.001), showing an improvement in SAGAT performance after a specific Aerobic Gymnastics training period. Taken together, these data have demonstrated that SAGAT is a specific, reliable and sensitive measurement of specific anaerobic performance in elite female Aerobic Gymnastics, presenting great potential to be largely applied in training settings.

Aerobic exercise training as therapy for cardiac and cancer cachexia.

Aerobic exercise training (AET) induces several skeletal muscle changes, improving aerobic exercise capacity and health. Conversely, to the positive effects of AET, the cachexia syndrome is characterized by skeletal muscle wasting. Cachexia is a multifactorial disorderassociated with other chronic diseases such as heart failure and cancer. In these diseases, an overactivation of ubiquitin-proteasome and autophagy systems associated with a reduction in protein synthesis culminates in severe skeletal muscle wasting and, in the last instance, patient's death. In contrast, AET may recycle and enhance many protein expression and enzyme activities, counteracting metabolism impairment and muscle atrophy. Therefore, the aim of the current review was to discuss the supposed therapeutic effects of AET on skeletal muscle wasting in both cardiac and cancer cachexia.

Influência do exercício físico na cognição: uma atualização sobre mecanismos fisiológicos / Influence of physical exercise on cognition: an update on physiological mechanisms / Influencia del ejercicio físico en la cognición: una actualización sobre mecanismos fisiológicos

Embora um crescente corpo de literatura corrobore o papel benéfico do exercício sobre a cognição, não há consenso sobre os mecanismos que norteiam as adaptações cerebrais agudas e crônicas ao exercício. A presente revisão narrativa tem como objetivo apresentar e discutir os mecanismos pelos quais o exercício afeta o desempenho cognitivo. Agudamente, especula-se que os efeitos do exercício sobre a resposta cognitiva sejam mediados por aumentos no fluxo sanguíneo cerebral e, por conseguinte, no aporte de nutrientes, ou por um aumento na atividade de neurotransmissores. Cronicamente, especula-se que o exercício possa promover adaptações em estruturas cerebrais e plasticidade sináptica que culminariam com melhoras cognitivas. Tais hipóteses são discutidas à luz das evidências científicas disponíveis, tanto em modelos animais quanto em humanos.

Although a growing body of literature has supported the beneficial role of exercise on cognition, there is no consensus on the mechanisms underlying acute and chronic cerebral adaptations to exercise. The present review aims to present and discuss the mechanisms by which exercise affects cognitive performance. It has been speculated that the acute effects of exercise on cognitive response may be mediated by increases in cerebral blood flow and, hence, in nutrient availability, or by increases in neurotransmitter activity. It has been also postulated that chronic exercise may induce adaptations in brain structures and the synaptic plasticity, which would result in cognitive improvements. These hypotheses are discussed in light of available scientific evidence in animal models and humans.

Aunque un creciente cuerpo de literatura corrobore el papel benéfico del ejercicio sobre la cognición, no hay consenso sobre los mecanismos que nortean las adaptaciones cerebrales agudas y crónicas al ejercicio. La presente revisión narrativa tiene como objetivo presentar y discutir los mecanismos por los cuales el ejercicio afecta el desempeño cognitivo. Agudamente, se especula que los efectos del ejercicio sobre la respuesta cognitiva sean mediados por aumentos en el flujo sanguíneo cerebral y, por consiguiente, en el aporte de nutrientes, o por un aumento en la actividad de neurotransmisores. Crónicamente, se especula que el ejercicio pueda promover adaptaciones en estructuras cerebrales y plasticidad sináptica que culminarían con mejoras cognitivas. Tales hipótesis son discutidas a la luz de las evidencias científicas disponibles, tanto en modelos animales como en humanos.

Efeito da suplementação de creatina, associada ou não ao treinamento de força, sobre a peroxidação lipídica em mulheres idosas / Effects of creatine supplementation associated or not with strength training upon lipid peroxidation in elderly women

O objetivo desse trabalho foi avaliar o efeito da suplementação de creatina associada ou não ao treinamento de força sobre a peroxidação lipídica em mulheres idosas. Foi conduzido um estudo clínico, randomizado, duplo-cego e controlado por placebo, no qual mulheres idosas foram randomizadas para compor quatro grupos: 1) suplementação com placebo (PL; n = 10); 2) suplementação com creatina (CR; n = 10); 3) suplementação com placebo associado ao treinamento de força (PL+TR; n = 6); e 4) suplementação com creatina associado ao treinamento de força (CR+TR; n = 8). Antes (PRE) e após 24 semanas (POS) de intervenção, foram coletadas amostras de sangue para posterior análise das concentrações plasmáticas de hidroperóxidos lipídicos por espectrofotometria. Nenhuma diferença estatística foi observada na concentração de hidroperóxidos lipídicos entre os grupos (PL: PRE = 48,7 ± 36,9; POS = 29,3 ± 18,8; delta = -13,0 ± 26,8; CR: PRE = 51,0 ± 46,0; POS = 54,2 ± 51,6; delta = -8,6 ± 30,2; PL+TR: PRE = 33,0 ± 11,2; POS = 47,3 ± 31,6; Δ = 14,3 ± 39,2; CR+TR: PRE = 18,5 ± 10,1; POS = 28,1 ± 17,9; delta = 9,7 ± 16,4 pmol.mg-1 de proteína total; p = 0,17). A suplementação de creatina associada ou não ao treinamento de força não afetou a peroxidação lipídica, um importante marcador de estresse oxidativo no plasma, em mulheres idosas.

The aim of this study was to evaluate the effects of creatine supplementation associated or not with strength training upon lipid peroxidation in older women. This was a clinical, randomized, double-blind, placebo-controlled trial. Older women were randomly allocated into four groups: 1) placebo supplementation (PL, n = 10), 2) creatine supplementation (CR; n = 10), 3) placebo supplementation associated with strength training (PL + RT, n = 6) and 4) creatine supplementation associated with strength training (CR + RT, n = 8). Before (PRE) and after 24 weeks (POST), blood samples were collected to measure lipid hydroperoxides concentration by spectrophotometry. No statistical difference was observed on the lipid hydroperoxides concentration between groups (PL: PRE = 48.7 ± 36.9; POST = 29.3 ± 18.8; Δ = -13.0 ± 26.8; CR : PRE = 51.0 ± 46.0; POST = 54.2 ± 51.6; Δ = -8.6 ± 30.2; + PL TR: PRE = 33.0 ± 11.2; POST = 47.3 ± 31.6, Δ = 14.3 ± 39.2; CR + TR: PRE = 18.5 ± 10.1; POST = 28.1 ± 17.9, Δ = 9.7 ± 16.4 pmol.mg-1 of total protein, p = 0.17). Creatine supplementation associated or not with strength training did not affect the lipid peroxidation, an important plasmatic marker of oxidative stress, in elderly women.

An overview of amines as nutritional supplements to counteract cancer cachexia.

Cancer cachexia is a complex multifactorial syndrome characterized by loss of skeletal muscle mass (with or without loss of fat mass) that cannot be fully reversed by conventional nutritional support and leads to progressive functional impairment. Recently, some amino acids and other amine dietary supplements have been highlighted in medical field due to positive effects upon diseases evolving skeletal muscle atrophy. Therefore, the aim of this brief review is to discuss the putative application of amines as dietary supplements to counteract skeletal muscle wasting on cancer cachexia. Specifically, we focus in two nutritional supplements: (1) branched-chain amino acids (BCAAs) and (2) creatine. Both BCAAs and creatine may attenuate proteolysis and enhance proteins synthesis in skeletal muscle. Although more experimental studies and clinical trials are still necessary to elucidate this therapeutic application, several evidences have demonstrated that amines supplementation is a promising coadjuvant treatment to cancer cachexia.

Creatine supplementation and resistance training in vulnerable older women: a randomized double-blind placebo-controlled clinical trial.

This study aimed to examine the efficacy of creatine supplementation, associated or not with resistance training, in vulnerable older women. A 24-week, double-blind, randomized, placebo-controlled trial was performed. Sixty subjects were assigned to compose the following groups: placebo (PL), creatine supplementation (CR), placebo with resistance training (PL+RT), and creatine supplementation with resistance training (CR+RT). The subjects were assessed at baseline and after 24weeks. The primary outcome was muscle strength, as assessed by one-repetition maximum (1-RM) tests. Secondary outcomes included appendicular lean mass, bone mass, biochemical bone markers, and physical function tests. The changes in 1-RM leg press were significantly greater in the CR+RT group (+19.9%) than in the PL (+2.4%) and the CR groups (+3.7%), but not than in the PL+RT group (+15%) (p=0.002, p=0.002, and p=0.357, respectively). The CR+RT group showed superior gains in 1-RM bench press (+10%) when compared with all the other groups (p≤0.05). The CR+RT group (+1.31%) showed greater appendicular lean mass accrual than the PL (-1.2%), the CR (+0.3%), and the PL+RT groups (-0.2%) (p≤0.05). The CR and the PL+RT groups experienced comparable gains in appendicular lean mass (p=0.62), but superior to those seen in the PL group. Changes in fat mass, bone mass and serum bone markers did not significantly differ between the groups (p>0.05). In conclusion, creatine supplementation combined with resistance training improved appendicular lean mass and muscle function, but not bone mass, in older vulnerable women. Clinicaltrials.gov: NCT01472393.

Creatine supplementation associated or not with strength training upon emotional and cognitive measures in older women: a randomized double-blind study.

PURPOSE: To assess the effects of creatine supplementation, associated or not with strength training, upon emotional and cognitive measures in older woman. METHODS: This is a 24-week, parallel-group, double-blind, randomized, placebo-controlled trial. The individuals were randomly allocated into one of the following groups (n=14 each): 1) placebo, 2) creatine supplementation, 3) placebo associated with strength training or 4) creatine supplementation associated with strength training. According to their allocation, the participants were given creatine (4 x 5 g/d for 5 days followed by 5 g/d) or placebo (dextrose at the same dosage) and were strength trained or not. Cognitive function, assessed by a comprehensive battery of tests involving memory, selective attention, and inhibitory control, and emotional measures, assessed by the Geriatric Depression Scale, were evaluated at baseline, after 12 and 24 weeks of the intervention. Muscle strength and food intake were evaluated at baseline and after 24 weeks. RESULTS: After the 24-week intervention, both training groups (ingesting creatine supplementation and placebo) had significant reductions on the Geriatric Depression Scale scores when compared with the non-trained placebo group (p = 0.001 and p = 0.01, respectively) and the non-trained creatine group (p < 0.001 for both comparison). However, no significant differences were observed between the non-trained placebo and creatine (p = 0.60) groups, or between the trained placebo and creatine groups (p = 0.83). Both trained groups, irrespective of creatine supplementation, had better muscle strength performance than the non-trained groups. Neither strength training nor creatine supplementation altered any parameter of cognitive performance. Food intake remained unchanged. CONCLUSION: Creatine supplementation did not promote any significant change in cognitive function and emotional parameters in apparently healthy older individuals. In addition, strength training per se improved emotional state and muscle strength, but not cognition, with no additive effects of creatine supplementation. TRIAL REGISTRATION: Clinicaltrials.gov NCT01164020.

Fisiologia do Exercício para alunos de graduação: uso de estratégias de ensino baseadas na metodologia dialética / Exercise Physiology for undergraduates: the use of teaching strategies basead on the dialectical method

A metodologia dialética propõe um ensino de dupla mão (professor-aluno) que provoque a aprendizagem por meio de tarefas contínuas dos sujeitos. Para isso, o professor assume o papel de mediador e dirige as diferentes atividades. Nesse contexto, a Fisiologia do Exercício é uma disciplina academicamente orientada que está inserida em um ambiente dinâmico, e a utilização de estratégias de ensino se faz necessária para otimizar a apropriação do conhecimento de forma ativa, além de contribuir para a maior autonomia dos estudantes universitários. Portanto, o objetivo do presente estudo foi o de utilizar diferentes estratégias de ensinagem por meio de atividades propostas aos alunos na disciplina de Fisiologia da Atividade Motora I da Escola de Educação Física e Esporte da Universidade de São Paulo e correlacionar o desempenho do aluno com a sua participação nessas atividades propostas. Nossos principais achados demonstram correlações significativas e positivas entre a presença nas aulas e o desempenho nas avaliações (p < 0,0001; r = 0,84), bem como entre a realização das atividades propostas e o desempenho nas avaliações (p < 0,0001; r = 0,69). Em conjunto, esses dados sugerem que a utilização de diferentes estratégias de ensinagem baseadas na metodologia dialética com a ativa participação dos alunos é essencial para um bom rendimento acadêmico, sendo altamente recomendada para o ensino da Fisiologia do Exercício...

The dialectic method proposes a two-way teaching (teacher-student) that causes learning through ongoing task of the subjects. For this, the teacher assumes the role of mediator and directs several activities. In line with the above, Exercise Physiology is an academically oriented discipline undergoing in a dynamic environment, and the use of different teaching strategies is needed to optimize the appropriation of knowledge in an active way and contribute to the greater autonomy of university students. Therefore, the aim of this study was apply different strategies in the course entitled "Physiology of the Motor Activity I" at School of Physical Education and Sport of University of Sao Paulo and assess a correlation between students participation and students performance. We used teaching strategies such as exposition and dialogue classes, practical classes, conversations with experts, directed study, study of scientific texts, concept mapping, case study and study of the environment in order to optimize the appropriation of the concepts of exercise physiology with emphasis on neuromuscular and cardiovascular physiology exercise. Our main findings show significant and positive correlations between the presence in classes and the performance evaluations (p < 0.0001, r = 0.84) as well as between the tasks proposed and the performance evaluations (p < 0.0001; r = 0.69). Altogether, these data suggest that using different teaching strategies based on the dialectic method associated with the participation of students is essential for a good academic performance in Exercise Physiology...

Influência da suplementação de creatina sobre a massa óssea de ratos espontaneamente hipertensos / Influence of creatine supplementation on bone mass of spontaneously hypertensive rats

INTRODUÇÃO: Recentes evidências indicam que a suplementação de creatina (Cr) é capaz de aumentar a densidade mineral óssea (DMO) no fêmur de ratos saudáveis em crescimento. Entretanto, há poucos estudos que testam a efetividade da suplementação desse nutriente em condições de perda óssea. OBJETIVO: Investigar o efeito da suplementação de Cr na DMO e no conteúdo mineral ósseo (CMO) de ratos espontaneamente hipertensos (SHR), um modelo experimental de baixa massa óssea. MATERIAIS E MÉTODOS: Dezesseis ratos SHR machos com 8 meses de idade foram randomizados em dois grupos experimentais pareados pelo peso corporal, a saber: 1) Pl: SHR tratados com placebo (água destilada; n = 8); e 2) Cr: SHR tratados com Cr (n = 8). Após nove semanas de suplementação os animais foram eutanasiados e o fêmur e a coluna vertebral (L1-L4) foram analisados por densitometria óssea (Dual Energy X-Ray Absorptiometry). RESULTADOS: Não houve diferença significativa na DMO (Pl = 0,249 ± 0,003 g/cm² vs. Cr = 0,249 ± 0,004 g/cm²; P = 0,95) e no CMO (Pl = 0,509 ± 0,150 g vs. Cr = 0,509 ± 0,017 g; P = 0,99) da coluna vertebral e na DMO (Pl = 0,210 ± 0,004 g/cm² vs. Cr = 0,206 ± 0,004 g/cm2;P = 0,49) e no CMO (Pl = 0,407 ± 0,021 g vs. Cr = 0,385 ± 0,021 g; P = 0,46) do fêmur total entre os grupos experimentais. CONCLUSÃO: Neste estudo, usando um modelo experimental de baixa massa óssea, a suplementação de Cr não afetou a massa óssea.

INTRODUCTION: Recent evidence has suggested that creatine supplementation (Cr) can increase the bone mineral density (BMD) of the femur in healthy growing rats. Nevertheless, studies assessing the efficacy of the Cr supplementation in conditions characterized by bone mass loss are scarce. OBJECTIVE: To investigate the effect of Cr supplementation on BMD and bone mineral content (BMC) in spontaneously hypertensive rats (SHRs), an experimental model of osteoporosis. MATERIALS AND METHODS: Sixteen 8-month-old male SHRs were randomly allocated into two groups matched by body weight: 1) Pl group: SHRs treated with placebo (distilled water; n = 8); and 2) Cr group: SHRs treated with Cr (n = 8). After nine weeks of supplementation, the animals were euthanized and their femur and spine (L1-L4) were analyzed by use of densitometry (Dual Energy X-Ray Absorptiometry). RESULTS: No significant difference was observed between the groups regarding either the spine or the total femur measures as follows: spine - BMD (Pl = 0.249 ± 0.003 g/cm² vs. Cr = 0.249 ± 0.004 g/cm²; P = 0.95) and BMC (Pl = 0.509 ± 0.150 g vs. Cr = 0.509 ± 0.017 g; P > 0.99); and total femur - BMD (Pl = 0.210 ± 0.004 g/cm² vs. Cr = 0.206 ± 0.004 g/cm²; P > 0.49) and BMC (Pl = 0.407 ± 0.021 g vs. Cr = 0.385 ± 0.021 g; P > 0.46). CONCLUSION: In this study, using the experimental model of osteoporosis, Cr supplementation had no effect on bone mass.

Influence of creatine supplementation on bone mass of spontaneously hypertensive rats.

INTRODUCTION: Recent evidence has suggested that creatine supplementation (Cr) can increase the bone mineral density (BMD) of the femur in healthy growing rats. Nevertheless, studies assessing the efficacy of the Cr supplementation in conditions characterized by bone mass loss are scarce. OBJECTIVE: To investigate the effect of Cr supplementation on BMD and bone mineral content (BMC) in spontaneously hypertensive rats (SHRs), an experimental model of osteoporosis. MATERIALS AND METHODS: Sixteen 8-month-old male SHRs were randomly allocated into two groups matched by body weight: 1) Pl group: SHRs treated with placebo (distilled water; n = 8); and 2) Cr group: SHRs treated with Cr (n = 8). After nine weeks of supplementation, the animals were euthanized and their femur and spine (L1-L4) were analyzed by use of densitometry (Dual Energy X-Ray Absorptiometry). RESULTS: No significant difference was observed between the groups regarding either the spine or the total femur measures as follows: spine - BMD (Pl = 0.249 ± 0.003 g/cm² vs. Cr = 0.249 ± 0.004 g/cm²; P = 0.95) and BMC (Pl = 0.509 ± 0.150 g vs. Cr = 0.509 ± 0.017 g; P > 0.99); and total femur - BMD (Pl = 0.210 ± 0.004 g/cm² vs. Cr = 0.206 ± 0.004 g/cm²; P > 0.49) and BMC (Pl = 0.407 ± 0.021 g vs. Cr = 0.385 ± 0.021 g; P > 0.46). CONCLUSION: In this study, using the experimental model of osteoporosis, Cr supplementation had no effect on bone mass.

Creatine-induced glucose uptake in type 2 diabetes: a role for AMPK-α?

This study focused on understanding the signaling mechanisms leading to GLUT-4 translocation and increased skeletal-muscle glucose uptake that follow creatine (Cr) supplementation in type 2 diabetes (n = 10). AMPK-α protein content presented a tendency to be higher (p = 0.06) after Cr supplementation (5 g/d for 12w). The changes in AMPK-α protein content significantly related (p < 0.001) to the changes in GLUT-4 translocation (r = 0.78) and Hb1Ac levels (r = -0.68), suggesting that AMPK signaling may be implicated in the effects of supplementation on glucose uptake in type 2 diabetes.

Anthropometric, physiological, performance, and nutritional profile of the Brazil National Canoe Polo Team.

The purpose of this study was to determine the physiological, anthropometric, performance, and nutritional characteristics of the Brazil Canoe Polo National Team. Ten male canoe polo athletes (age 26.7 ± 4.1 years) performed a battery of tests including assessments of anthropometric parameters, upper-body anaerobic power (Wingate), muscular strength, aerobic power, and nutritional profile. In addition, we characterized heart rate and plasma lactate responses and the temporal pattern of the effort/recovery during a simulated canoe polo match. The main results are as follows: body fat, 12.3 ± 4.0%; upper-body peak and mean power, 6.8 ± 0.5 and 4.7 ± 0.4 W · kg(-1), respectively; 1-RM bench press, 99.1 ± 11.7 kg; peak oxygen uptake, 44.3 ± 5.8 mL · kg(-1) · min(-1); total energy intake, 42.8 ± 8.6 kcal · kg(-1); protein, carbohydrate, and fat intakes, 1.9 ± 0.1, 5.0 ± 1.5, and 1.7 ± 0.4 g · kg(-1), respectively; mean heart rate, 146 ± 11 beats · min(-1); plasma lactate, 5.7 ± 3.8 mmol · L(-1) at half-time and 4.6 ± 2.2 mmol · L(-1) at the end of the match; effort time (relative to total match time), 93.1 ± 3.0%; number of sprints, 9.6 ± 4.4. The results of this study will assist coaches, trainers, and nutritionists in developing more adequate training programmes and dietary interventions for canoe polo athletes.