RESUMO
The aim of this study was to identify the main components that determine firefighters' level of physical fitness using a stair-climbing test. The age, weight, height, body fat, and VO(2max) of the firefighters were recorded before the trial, and percentage of heart rate reserve (%HRR) was recorded during the stair climbing. Nonlinear modeling of HRR time series and Principal Component Analysis (PCA) was applied to the data to isolate a small number of variables that quantify overall individual physical fitness. The HRR was represented as a function of time using the sum of linear and trigonometric functions. Four main factors that influence performance, obtained from PCA analysis, emerged (78.2% of total explained variance): the capacity to carry the extra load (22.8% of total variance); the effect of body fat (19.6% of total variance); the influence of age in the task (19.3% of total variance); and the overall fitness level (16.4% of total variance). This approach allowed us to make a rapid assessment of each subject's fitness level. Such an assessment could be used in planning individualized functional training programs to improve each firefighter's job performance and reduce injuries and hence save time, energy, and financial resources.
Assuntos
Teste de Esforço/métodos , Bombeiros , Aptidão Física/fisiologia , Adulto , Fatores Etários , Distribuição da Gordura Corporal , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/fisiologia , Análise de Componente PrincipalRESUMO
The aim of this research was to determine physiologic responses to typical activities of military Italian firefighters. Heart rate (HR), metabolic equivalent units (MET), skin temperature ( T.Sk.), and galvanic skin response (GSR) were measured in 13 firefighters (age = 36.3 +/- 6.9 yr; period of military fire service = 16.8 +/- 7 yr) during the acclimation phase (5 min standing, still dressed in their protective clothing), the work phase (simulated firefighting situations), and the following 24 hours. Multivariate linear step-wise regression showed that body mass index was highly correlated with mean and minimal HR values during the acclimation phase (beta 0.59, p < 0.001; beta 1.90, p = 0.003) and with mean and maximum HR values during the work phase (beta 1.08, p = 0.05; beta 1.17, p = 0.04), increasing cardiovascular stress. Firefighting tasks were associated with high energy expenditure. The minimum and mean MET values, during the acclimation phase, were significantly correlated with age (beta 0.49, p = 0.008 and beta 0.46, p < 0.01). During the work phase, maximal MET values were also strongly correlated with weight (beta 0.51, p = 0.03). No correlations between predictor and dependent variables were found for GSR; however, the high GSR levels recorded during the work phase returned to normal values only 12 hours after completion of the work phase, indicating that high levels of psychological stress remain, even after physical recovery. The data obtained in this study demonstrate that the physical fitness and anthropometric characteristics of firefighters influence the performance of firefighting tasks. These results may be useful to set up specific training that meets the real needs of firefighters in terms of physical fitness.
Assuntos
Incêndios , Esforço Físico/fisiologia , Estresse Fisiológico/fisiologia , Análise e Desempenho de Tarefas , Adulto , Antropometria , Estudos Transversais , Metabolismo Energético , Frequência Cardíaca/fisiologia , Temperatura Alta/efeitos adversos , Humanos , Itália , Modelos Lineares , Masculino , Roupa de Proteção , Temperatura Cutânea/fisiologiaRESUMO
Type 2 diabetes (T2D) is an age-related chronic disease associated with metabolic dysregulation, chronic inflammation, and activation of peripheral blood mononuclear cells (PBMC). The aim of this study was to assess the effects of a concurrent exercise training program on inflammatory status and metabolic parameters of T2D patients. Sixteen male patients (age range 55-70) were randomly assigned to an intervention group (n = 8), which underwent a concurrent aerobic and resistance training program (3 times a week; 16 weeks), or to a control group, which followed physicians' usual diabetes care advices. Training intervention significantly improved patients' body composition, blood pressure, total cholesterol, and overall fitness level. After training, plasma levels of adipokines leptin (-33.9%) and RBP4 (-21.3%), and proinflammatory markers IL-6 (-25.3%), TNF-α (-19.8%) and MCP-1 (-15.3%) decreased, whereas anabolic hormone IGF-1 level increased (+16.4%). All improvements were significantly greater than those of control patients. Plasma proteomic profile of exercised patients showed a reduction of immunoglobulin K light chain and fibrinogen as well. Training also induced a modulation of IL-6, IGF-1, and IGFBP-3 mRNAs in the PBMCs. These findings confirm that concurrent aerobic and resistance training improves T2D-related metabolic abnormalities and has the potential to reduce the deleterious health effects of diabetes-related inflammation.