Fatigue and rapid hamstring/quadriceps force capacity in professional soccer players

The aim of this study was to investigate the effect of fatigue induced by an exhaustive laboratory-based soccer-specific exercise on different hamstrings/quadriceps (H:Q) ratios of soccer players. Twenty-two male professional soccer players (23·1 ± 3·4 year) performed maximal eccentric (ecc) and concentric (con) contractions for knee extensors (KE) and flexors (KF) at 60° s-1 and 180° s-1 to assess conventional (Hcon:Qcon) and functional (Hecc:Qcon) ratios. Additionally, they performed maximal voluntary isometric contraction for KE and KF, from which the maximal muscle strength, rate of force development (RFD) and RFD H:Q strength ratio (RFDH:Q) were extracted. Thereafter, subjects were performed an exhaustive laboratory-based soccer-specific exercise and a posttest similar to the pretest. There was significant reduction in Hcon:Qcon (0·60 ± 0·06 versus 0·58 ± 0·06, P<0·05) and in Hecc:Qcon (1·29 ± 0·2 versus 1·16 ± 0·2, P<0·01) after the soccer-specific exercise. However, no significant difference between Pre and Post exercise conditions was found for RFDH:Q at 0-50 (0·53 ± 0·23 versus 0·57 ± 0·24, P>0·05) and 0-100 ms (0·53 ± 0·17 versus 0·55 ± 0·17, P>0·05). In conclusion, H:Q strength ratios based on peak force values are more affected by fatigue than RFDH:Q obtained during early contraction phase. Thus, fatigue induced by soccer-specific intermittent protocol seems not reduce the potential for knee joint stabilization during the initial phase of voluntary muscle contraction. copy; 2012 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

Long-term creatine supplementation improves muscular performance during resistance training in older women

This study examined the effects of long-term creatine supplementation combined with resistance training (RT) on the one-repetition maximum (1RM) strength, motor functional performance (e.g., 30-s chair stand, arm curl, and getting up from lying on the floor tests) and body composition (e.g., fat-free mass, muscle mass, and % body fat using DEXA scans) in older women. Eighteen healthy women (64.9 ± 5.0 years) were randomly assigned in a double-blind fashion to either a creatine (CR, N = 9) or placebo (PL, N = 9) group. Both groups underwent a 12-week RT program (3 days week-1), consuming an equivalent amount of either creatine (5.0 g day-1) or placebo (maltodextrin). After 12 week, the CR group experienced a greater (P < 0.05) increase (Δ%) in training volume (+164.2), and 1RM bench press (+5.1), knee extension (+3.9) and biceps curl (+8.8) performance than the PL group. Furthermore, CR group gained significantly more fat-free mass (+3.2) and muscle mass (+2.8) and were more efficient in performing submaximal-strength functional tests than the PL group. No changes (P > 0.05) in body mass or % body fat were observed from pre- to post-test in either group. These results indicate that long-term creatine supplementation combined with RT improves the ability to perform submaximal-strength functional tasks and promotes a greater increase in maximal strength, fat-free mass and muscle mass in older women. © 2012 Springer-Verlag Berlin Heidelberg.

Associação entre composição corporal, equilíbrio e mobilidade de idosos com 80 anos ou mais

Study design: cross-sectional study. Objective: The objective of this study was to analyze the association between body composition, mobility and balance of elderly aged 80 years or older. Methods: The sample consisted of 123 elderly aged 80 and 95 years (83.2 ± 2.7 years) with 78 women (83.2 ± 2.9 years) and 45 men (83.2 ± 2, 4 years) residing in the city of Presidente Prudente - SP. Assessment of body composition was made by absorpiometria dual energy X-ray (DXA). The mobility and balance were assessed by means of tests of speed walking, and static balance lower limb strength. For statistical analysis we carried out the chi-square test, the software used was SPSS (13.0) and the significance level was set at 5%. Results: In males, those with higher performance in the functional tests showed higher percentages of muscle mass (MM) (35.6%) compared to lower performance (15.6%), p = 0.026. In the female group, the elderly with higher performance on tests showed higher bone mineral density (BMD) values (30.8%) compared with those with lower performance (20.5%) p = 0.041. Conclusion: MM for elderly males and BMD for females were the components of body composition that is associated with functional capacity.

Perfil de idosos em acompanhamento ambulatorial e preditores de quedas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Are early and late rate of force development differently influenced by fast-velocity resistance training?

This study examined the effect of fast-velocity concentric isokinetic resistance training (FV) on the rate of force development (RFD) at early (<100 ms) and late phases (>100 ms) of rising muscle force. Nine men participated in a 6-week resistance training intervention for the lower body, and nine matched subjects participated as controls (CON). During concentric isokinetic (180°s-1) knee extension training, subjects were instructed to do each contraction 'as fast and forcefully as possible'. Maximal muscle strength (MVC) and RFD (0-10, 0-20, ..., 0-250 ms from the onset of contraction) were measured during maximal voluntary isometric contraction of the knee extensors (KE). There were no significant changes in MVC of KE in both groups after intervention (FV = 314·2 ± 101·1 versus 338·7 ± 88·0 N{bullet operator}m, P>0·05; CON = 293·3 ± 94·8 versus 280·0 ± 72·2 N{bullet operator}m, P>0·05). The RFD increased 39-71% at time intervals up to 90 ms from the onset of the contraction (P<0·05), whereas no change occurred at later time intervals. Similarly, relative RFD (i.e.%MVC{bullet operator}s-1) (RFDr) increased 33-56% at time intervals up to 70 ms from the onset of the contraction (P<0·05). It can be concluded that a short period of resistance training performed with concentric fast-velocity isokinetic muscle contractions is able to enhance RFD and RFDr obtained at the early phase of rising muscle force. © 2013 The Authors Clinical Physiology and Functional Imaging © 2013 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

Age Affects Exercise-Induced Improvements in Heart Rate Response to Exercise

The aim of the present study was to analyze the effects of age on cardiorespiratory fitness (CRF), muscle strength and heart rate (HR) response to exercise adaptation in women in response to a long-term twice-weekly combined aerobic and resistance exercise program. 85 sedentary women, divided into young (YG; n=22, 30.3±6.2 years), early middle-aged (EMG; n=28, 44.1±2.5 years), late middle-aged (LMG; n=20, 56.7±3.5 years) and older (OG; n=15, 71.4±6.9 years) groups, had their CRF, muscle strength (1-repetition maximum test) and HR response to exercise (graded exercise test) measured before and after 12 months of combined exercise training. Exercise training improved CRF and muscle strength in all age groups (P<0.05), and no significant differences were observed between groups. Exercise training also improved resting HR and recovery HR in YG and EMG (P<0.05), but not in LMG and OG. Maximal HR did not change in any group. Combined aerobic and resistance training at a frequency of 2 days/week improves CRF and muscle strength throughout the lifespan. However, exercise-induced improvements in the HR recovery response to exercise may be impaired in late middle-aged and older women. © Georg Thieme Verlag KG.

Análise funcional da musculatura do assoalho pélvico pós-parto em mulheres primigestas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Importância da eletromiografia na avaliação funcional da musculatura do assoalho pélvico em mulheres nulíparas continentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eletroestimulador funcional de oito canais com malha de realimentação utilizando Controlador Digital

Pós-graduação em Engenharia Elétrica - FEIS

Efeitos do treinamento resistido sobre a variabilidade da frequência cardíaca, capacidade funcional e força muscular periférica na DPOC

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito de treinamentos resistidos sobre marcadores inflamatórios, força e massa magra corporal de pacientes com doença pulmonar obstrutiva crônica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Exercício resistido em cardiopatas: revisão sistemática da literatura e análise do comportamento autonômico em recuperação pós-exercício resistido aplicado de forma aguda

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos do treinamento resistido concêntrico e excêntrico sobre a modulação autonômica cardíaca e parâmetros cardiovasculares

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos do treinamento resistido concêntrico versus excêntrico sobre parâmetros clínicos e funcionais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A corda elástica como instrumento de treinamento resistido em paciêntes com doença pulmonar obstrutiva crônica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)