RESUMO
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.
Assuntos
Creatina/administração & dosagem , Suplementos Nutricionais , Contração Muscular/efeitos dos fármacos , Força Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Substâncias para Melhoria do Desempenho/administração & dosagem , Treinamento Resistido , Absorciometria de Fóton , Fatores Etários , Idoso , Análise de Variância , Composição Corporal/efeitos dos fármacos , Brasil , Método Duplo-Cego , Feminino , Humanos , Pessoa de Meia-Idade , Atividade Motora/efeitos dos fármacos , Músculo Esquelético/diagnóstico por imagem , Tamanho do Órgão/efeitos dos fármacos , Fatores Sexuais , Fatores de TempoRESUMO
The purpose of this study was to analyze factors associated with musculoskeletal disorders and disability in elementary teachers. This is a cross-sectional study from a representative sample of Brazilian elementary teachers (nâ¯=â¯530). Data were collected using a self-report questionnaire. Sociodemographic, work-related, and behavioural characteristics were the exposure variables. The outcomes were musculoskeletal symptoms, disability, and musculoskeletal disease. Musculoskeletal disease was used as an outcome, as well as an exposure variable when musculoskeletal symptoms and disability were the outcomes. Prevalence ratios (PR) were estimated by Poisson regression. Variables associated with musculoskeletal symptoms were: length of employment ≥20 years (PRâ¯=â¯1.41), perception of inappropriate infrastructure of schools (RPâ¯=â¯1.21), physical activity (PRâ¯=â¯0.80), and high stress (PRâ¯=â¯1.16) for upper limbs; high stress (PRâ¯=â¯1.23) and perception of inappropriate infrastructure of schools (RPâ¯=â¯1.16) for back/neck; common mental disorders (PRâ¯=â¯1.14 to 1.30), and musculoskeletal disease (PRâ¯=â¯1.19-1.62) for all regions of the body. Musculoskeletal disease (PRâ¯=â¯2.46 to 3.37) and perception of inappropriate infrastructure of schools (PRâ¯=â¯1.53 to 1.95) were associated to disability in all regions of the body. Length of employment >20 years was associated with disability in the upper limbs (PRâ¯=â¯2.06). Common mental disorders were associated with disability in the upper limbs (PRâ¯=â¯1.53) and back and neck (PRâ¯=â¯1.47) while sitting time >120â¯min/day was inversely associated with disability in the lower limbs (PRâ¯=â¯0.64). The predictors of musculoskeletal disease were length of employment ≥20 years (PRâ¯=â¯1.97), perception of inappropriate infrastructure of schools (PRâ¯=â¯1.57), strength and flexibility activities (PRâ¯=â¯1.66), TV viewing timeâ¯≥â¯120â¯min (PRâ¯=â¯1.37), sports practice (PRâ¯=â¯0.39), and common mental disorders (PRâ¯=â¯1.39). Although the associations varied according to the outcome, common mental disorders, perception of inappropriate infrastructure of schools, high stress, and length of employment are variables to be considered in the prevention of musculoskeletal disorders in teachers. When analyzed as an exposure variable, musculoskeletal disease was the main predictor of musculoskeletal symptoms and disability.