Heated environment offsets the cardiovascular responses to prolonged rowing exercise in competitive athletes.

Prolonged rowing exercise sessions are often prescribed considering competitive training schedules, and under hostile environments (e.g., heated ambient). The study aimed to investigate the effect of heat stress (HS) on physical performance, Lactate concentration ([Lac]), and cardiorespiratory responses during prolonged exercise sessions in competitive rowers. Twelve rowers performed preliminary exercise tests (2-km test and five-step incremental lactate test) to assess the target workload intensity corresponding to a 2.5 mmol.L-1 of [Lac]. On two separate days, participants were enrolled in two exercise sessions of 12 km in a rowing machine under HS (∼30 °C) and thermal comfort (TC 22 °C) conditions. Heart rate (HR), stroke volume (SV), cardiac output (CO), oxygen uptake (VO2), [Lac], and the rating of perceptual exertion (RPE) were obtained. From baseline, HS increased the maximum temperature of the face compared to TC. Workload and VO2 reduced while RPE increased at 9- and 12-km of rowing exercise under HS compared to TC. From baseline to the last stage of exercise, HS shifted SV downwards and HR upwards compared to TC. Consequently, CO did not change between thermal conditions (TC vs. HS). Therefore, HS provokes a cardiovascular drift during prolonged rowing in comparison to TC. The last stages of prolonged rowing sessions under HS seem to be critical to physical performance and relative perceptual of effort in rowers.

Effects of Different Between Test Rest Intervals in Reproducibility of the 10-Repetition Maximum Load Test: A Pilot Study with Recreationally Resistance Trained Men.

The purpose of this study was to compare the effect of 24-, 36-, 48-, 72- and 96-hours between-test rest intervals on the reproducibility of the 10-RM smith machine back squat (BS), bench press (BP) and leg press at 45 degrees (LP45) exercises. Twelve resistance trained men (26.6 ± 4.5 yrs; 179.0 ± 5.5 cm; 92.2 ± 24.6 kg) performed five sets of identical 10-repetition maximum (10-RM) tests for the BS, BP, LP45 exercises, each set with a different interval between tests: 1) twenty-four hours (Post-24), 2) thirty-six hours (Post-36), 3) forty-eight hours (Post-48), 4) seventy-two (Post-72), and 5) ninety-six hours (Post-96). Significant differences in 10-RM from pretest to posttest were observed for BS in Post-24 (p < 0.001; Δ% = -12.62), Post-36 (p < 0.001; Δ% = -6.57), and Post-96 (p = 0.015; Δ% = 6.84). Similarly, significant differences in 10-RM from pretest to posttest were observed for BP in Post-24 (p < 0.001; Δ% = -9.22), Post-36 (p = 0.032; Δ% = -3.04), and Post-96 (p < 0.001; Δ% = 5.37). Finally, significant differences in 10-RM from pretest to posttest were observed for LP45 in Post-24 (p < 0.001; Δ% = -16.55), Post-36 (p = 0.032; Δ% = -5.09), and Post-96 (p < 0.001; Δ% = 5.54). The reproducibility of 10-RM was examined using intraclass correlation coefficients; BS: 0.944, 0.977, 0.988, 0.986, and 0.954 for Post-24, Post-36, Post-48, Post-72, and Post-96, respectively; BP: 0.894, 0.966, 0.966, 0.960, and 0.976; and LP45: 0.832, 0.957, 0.984, 0.974, and 0.977 5. Based on the findings, the optimal between test rest interval duration for 10-RM testing, to provide the best reproducibility, in resistance trained men appears to be 48 to 72 hours for the BS, BP, and LP45 exercises.

Oxygen Uptake On-Kinetics during Low-Intensity Resistance Exercise: Effect of Exercise Mode and Load.

Oxygen uptake (VO2) kinetics has been analyzed through mathematical modeling of constant work-rate exercise, however, the exponential nature of the VO2 response in resistance exercise is currently unknown. The present work assessed the VO2 on-kinetics during two different sub maximal intensities in the inclined bench press and in the seated leg extension exercise. Twelve males (age: 27.2 ± 4.3 years, height: 177 ± 5 cm, body mass: 79.0 ± 10.6 kg and estimated body fat: 11.4 ± 4.1%) involved in recreational resistance exercise randomly performed 4-min transitions from rest to 12% and 24% of 1 repetition maximum each, of inclined bench press (45°) and leg extension exercises. During all testing, expired gases were collected breath-by-breath with a portable gas analyzer (K4b2, Cosmed, Italy) and VO2 on-kinetics were identified using a multi-exponential mathematical model. Leg extension exercise exhibited a higher R-square, compared with inclined bench press, but no differences were found in-between exercises for the VO2 kinetics parameters. VO2 on-kinetics seems to be more sensitive to muscle related parameters (upper vs. lower body exercise) and less to small load variations in the resistance exercise. The absence of a true slow component indicates that is possible to calculate low-intensity resistance exercise energy cost based solely on VO2 measurements.

Thermal Asymmetries and Mean Foot Temperature.

Foot problems can cause pain and discomfort, limiting the activities of many individuals. Infrared thermography may be useful for early detection of abnormal temperatures using various ways of calculating the mean foot temperature (MFT) to analyze asymmetries and differences between different groups. The aim of this study was to compare two protocols for calculating the MFT, identifying the magnitude of asymmetries in several regions and their correlations with the forehead temperature and brain temperature tunnel(BTT).Nineteen healthy volunteers of both genders aged between 18 and 55 years participated in the study.Data collection included anamnesis, body mass measurement, stature, glycaemia, body core temperature and acquisition of thermal images of the feet and face. The Wilcoxon test revealed that the mean foot temperature calculated using hallux, 2nd, 3rd, 4th and 5th toes, 1st, 3rd and 5th metatarsal heads and heel, was lower than that calculated without the four lesser toes (Z = -2.636, p = 0.008).However, the asymmetry between the two feet was the same in both cases (medianof 0.4 °C). The correlations of the MFT with the forehead temperature and BTT were positive and significant for the two forms of calculation, and the correlation was stronger when all toes were used to calculate the mean (forehead: ρ = 0.654, p = 0.002, BTT: ρ = 0.617, p = 0.005). The study showed the relevance of the toes in the analysis of the MFT, and it may be important to evaluate asymmetries in the toes to detect abnormal thermal patterns. This finding suggests that it is preferable to use MFT calculated with all toes.

Mathematical Model for Body Fat Percentage in Military using Thermal Imaging and Circumferences.

The prevalence of overweight and obesity has gradually increased throughout the world. In this sense, body composition evaluation' methods have gained special attention in some research areas. The aim of this study was to propose a mathematical model to estimate body fat percentage (BF%) of men from thermal imaging and body circumferences variables and using as gold standard values obtained by Dual-Energy XRay Absorptiometry (DXA). This was a cross-sectional study. A Sample of 47 men aged from 18 to 20 years was involved in the study. They were selected among soldiers from Brazilian Army. Data collection was carried out in just one day, in the following sequence: thermal imaging, body fat percentage assessed by DXA and anthropometric measures. It was performed the identification of the skin temperature strongest correlated with BF% in each body segment (trunk, upper and lower limbs). The same procedure was done with anthropometrics variables. After that, these variables were tested in the linear regression model. Waist, abdomen and hip circumferences, as expected, showed strong positive correlations with BF% (r = 0.826, 0.873, and 0.853, respectively). Since the skin temperature values tended to negative correlation with BF%, the best results were found for mean skin temperature of the anterior face of the trunk (r = -0 753) and posterior face (r = -0723). The best model reaches an R square of 0.800 using just one anthropometric and one skin temperature variable (BF% =32.34 + (0.6 x AC) - (1.87 x ATSkTMean)), where AC means abdominal circumference and ATSkTMean means the mean skin temperature from the anterior face of the trunk. The proposed model can be used by Brazilian Army to estimate BF% of soldiers and male military personal aged from 18 to 20 years.

Effect of Cold-Water Immersion on Elbow Flexors Muscle Thickness After Resistance Training.

Matos, F, Neves, EB, Rosa, C, Reis, VM, Saavedra, F, Silva, S, Tavares, F, and Vilaça-Alves, J. Effect of cold-water immersion on elbow flexors muscle thickness after resistance training. J Strength Cond Res 32(3): 756-763, 2018-Cold-water immersion (CWI) is commonly applied to speed up the recovery process after exercise. Muscle damage may induce a performance reduction and consequence of the intramuscular pressure induced by the muscular swelling. The aim of the study was to verify the CWI effects on muscle thickness (MT) behavior of the elbow flexors after a strength training (ST) protocol. Eleven men were submitted to an ST, performed in 2 different weeks. In one of the weeks, subjects experienced a passive recovery. In the other, subjects were submitted to a CWI (20 minutes at 5-10° C). Ultrasound (US) images were taken before, after, as well as 24, 48, and 72 hours after exercise, to evaluate the MT. Muscle thickness in both exercise arm (EA) and control arm (CA) was significantly higher 48 and 72 hours after exercise when subjects were submitted to a passive recovery compared with the CWI (p = 0.029, p = 0.028, p = 0.009, and p = 0.001, 48 hours, 72 hours, EA, and CA, respectively). When each arm was analyzed with or without using CWI individually, significantly higher MT was observed in the EA with CWI: before exercise in relation to 72 hours after exercise (p = 0.042) and after exercise in relation to the other measurements (p = 0.003, p = 0.003, p = 0.038, and p < 0.0001, before exercise and 24, 48, 72 hours after exercise, respectively). The evaluation of MT by US provides evidence that CWI after ST (and 24 hours after exercise) may reduce muscle swelling in the postexercise days when compared with a passive recovery. Seems to be a paradox between the uses of CWI for an acute reduction of muscle swelling.

Comparing consumption oxygen during and after squat exercise in Smith Machine and whole-body vibration.

Currently the physical exercise in whole body vibration platforms has become popular among people that frequenting gym and physiotherapy clinics. The objective of this study was to compare the oxygen consumption in the squat exercise performed at Smith Machine and squat performed on the vibration platform following the protocols usually referenced in both types of exercise (with load of 70% in the Smith Machine and unloaded on the vibration platform). The sample consisted of eight male subjects, with a mean age of 22.75 ± 2.05 years, an average body mass 74.50 ± 9.50kg, a stature of 1.79 ± 0.63m and estimated body fat percentage of 5.01 ± 0.94%. The volunteers performed two exercise sessions, one in the Smith Machine (AGSM) and the other on the vibration platform (AGPP). Each session consisted in 5 sets of 10 repetitions each, with a cadence of 40 beat.min(-1). The load used in the exercise AGSM performance was 70% of 1RM and in the AGPP was used a vibration frequency of 50 Hz, during 60 seconds in high amplitude. The order of the sections was randomized, with seven days apart. The AGPP session presented VO2 absolute = 0.95 ± 0.21L/min, VO2 relative = 12.86 ± 2.43ml/kg/min, and HR = 93.69 ± 10.55 beats/min; and the AGSM session presented VO2 absolute = 1.33 ± 0.29 L/min, VO2 relative = 17.91 ± 2.70 ml/kg/min, and HR = 120.69 ± 14.21 beats/min. The VO2 and HR values of the AGSM session were significantly higher than that found in AGPP session.

Anthropometric profile and diabetic foot risk: a cross-sectional study using thermography.

Diabetes is one of the greatest todays public health problems with enormous social and economic implications for society. Diabetic foot disorders represent a substantial economic burden with detrimental effects on quality of life with special impairment in physical domain. Early detection strategies of these complications should be implemented in order to avoid possible wounds, ulcerations and amputations. This work can be characterized as a cross-sectional study with an analytical approach. It involved 44 volunteers of both genders (22 women and 22 men; 66.70 ± 6.26 years of age) with type 2 diabetes (diagnosed at 11.84 ± 8.22 years), selected among the candidates to Diabetes em Movimento® (a community-based exercise program for patients with type 2 diabetes developed in the city of Vila Real, Portugal). Foot plantar thermal images were acquired through a high-resolution infrared camera (FLIR Systems Inc. Model SC2000; 320 × 240 pixels). Three regions of interest (ROI) were defined for evaluation: first finger, fifth finger and the heel. From the three pairs of ROIs evaluated, the higher temperature asymmetry was selected for diabetic foot risk analysis. The results showed the existence of a positive and significant association between BMI and fat mass with asymmetries in feet temperature. Three subjects with diabetes-related foot complications (ROIs higher temperature asymmetry ≥ 2.20 °C) were identified in the sample. All participants with detected diabetes-related foot complications were obese (BMI ≥ 30 kg/m2) with high levels of body fat (≥ 45%). It can be concluded that exist a positive association either of BMI (r=0.399, p=0.007) either of body fat percentage (r=0.432, p=0.003), with diabetic foot risk in patients with type 2 diabetes.

Different responses of the skin temperature to physical exercise: Systematic review.

Studies suggest that skin temperature behavior varies according to the type of exercise, intensity, duration, muscle mass and subcutaneous fat layer. In this sense, the aim of this study was to investigate the skin temperature behavior in the active muscles and other body segments, during and after exercise, according to the type and intensity of the exercise. A systematic literature review was conducted between November 2014 and March 2015 in the Web of Science database, using the terms "thermography" and "exercise" and "muscle" to achieve the objective of this study. During the research were found 55 scientific articles which were subjected to a selection process. Inclusion criteria were: Studies in human beings and original research. The exclusion criterion was the presence of subjects with some kind of disease. The seven papers that make up the present review are dated between 2008 and 2015. From all analyzed studies, it was possible to understand the general behavior of the active muscle skin temperature during the exercise, immediately after and in the 48h after exercise, according to the type and intensity of the exercise performed, which are illustrated in two figures. It can be concluded that the skin temperature over active muscles increases during high intensity anaerobic exercise, decreases slowly after exercise and increases again in the days after the exercise. On the other hand, during low intensity aerobic exercise, skin temperature over active muscles decreases, returning to normal values a few minutes after it and present a small rise in the following days. With regard to the skin temperature over non-active muscles, it can be seen that it decreases during exercise, returning to normal values a few minutes after it and rise similarly to the skin temperature over active muscles in the following days, in all types of exercises studied.

Impact of ammunition and military explosives on human health and the environment.

OBJECTIVE: To review the literature concerning the risks associated with the main xenobiotics contained in military ammunition and explosive residues and damage to human and environmental health. METHODOLOGY: Using "ammunition", "military", "environmental", "health", "explosive", "metal", "TNT", "RDX", "pollution", and "contamination" as search terms, a large database, namely ISI Web of Knowledge and PubMed, was searched for studies on military ammunition and explosive residues from 1989 to 2010. Other sources used to conduct the search included the library of the Toxicology Laboratory of the Center for Workers' Health and Human Ecology (CESTEH) at the National School of Public Health. RESULTS: In total, 15 different combinations were used with the search words above and 708 papers were found. Among them, 76 papers concerned this review. More than 12 references of interest were discovered in the library of the CESTEH. The results were organized into metals, dinitrotoluene, trinitrotoluene (TNT), and royal demolition explosive (RDX), showing their main uses, occurrence in the environment, the current toxic effects to human and environmental health, and remediation possibilities. CONCLUSION: Because military activities can cause the acute and chronic exposure of human beings, the public administration must aim politics towards suitable environmental management.

Comparando fatores de impacto bibliométricos computados a partir de três bases de dados: Web of Science, Scopus e SciELO. / Comparing impact factors from three databases: Web of Science, Scopus and SciELO.

O objetivo do presente trabalho foi analisar a comparabilidade de Fatores de Impacto (FIs) de revistas científicas a partir de três bancos de dados: o ISI Thompson (Web of Science), o Scopus e a Scielo, ano-base 2006. Para tal, a faixa de variação dos FIs em cada banco foi caracterizada, as diferenças das médias dos FIs entre os bancos foram analisadas por um teste t de Student pareado (?=0,05) e o coeficiente de correlação intraclasse (ICC) foi calculado para os bancos. Um total de 34 revistas da área de saúde foi analisado (12 da Scielo). Os FIs Scielo variaram na faixa de 0,02 a 0,60, enquanto que os FIs calculados a partir do banco Scopus situaram-se na faixa de 0,04 a 6,8, com uma variabilidade superior a obtida pelo ISI (0,12-6,60). As diferenças entre as médias foram estatisticamente significantes em todos os casos analisados, e o ICC teve valores máximo e mínimo, respectivamente, de 0,97 (ISI versus Scopus) e 0,45 (para os três bancos). Não foi possível identificar a origem das discrepâncias, uma vez que o cálculo dos FIs não é explícito. No entanto, diferenças (arbitrárias) nas bases de dados analisadas, assim como nos critérios de cômputo, introduzem alterações de complexa interpretação, tornando difícil o uso válido desses indicadores de forma rígida (por exemplo, utilizando-se pontos de corte específicos).

The objective of this study was to analyze the comparability of the Impact Factors (IFs) of scientific journals calculated from three databases: Thompson ISI, Scopus and SciELO, using the base-year 2006. With this aim, the IF variation range in each database was characterized, the IF mean differences across databases were analyzed by means of a Student matched t-test (?=0.05) and the Intraclass Correlation Coefficient (ICC) was estimated for the analyzed databases. A total of 34 journals were analyzed (12 SciELO). The SciELO IFs were in the range 0.02 to 0.60, while the IFs calculated from the Scopus database varied between 0.04 and 6.8, with a larger variability than that of those obtained by the ISI database (0.12 to 6.60). Mean differences were statistically significant in all the analyzed cases, and the ICC maximum and minimum values were respectively 0.97 (ISI versus Scopus) and 0.45 (for the three databases). It is not possible, however, to identify the origin of these discrepancies, since IF calculation procedures are not clearly specified. However, it is clear that (arbitrary) differences in the databases and on their calculation criteria make changes difficult to interpret, making problematic the rigid use of these indicators (e.g. by means of specific cut-off points).

Liquid crystal phase and waterlike anomalies in a core-softened shoulder-dumbbells system.

Using molecular dynamics we investigate the thermodynamics, dynamics, and structure of 250 diatomic molecules interacting by a core-softened potential. This system exhibits thermodynamic, dynamic, and structural anomalies: a maximum in density-temperature plane at constant pressure and maximum and minimum points in the diffusivity and translational order parameter against density at constant temperature. Starting with very dense systems and decreasing density the mobility at low temperatures first increases, reaches a maximum, then decreases, reaches a minimum and finally increases. In the pressure-temperature phase diagram the line of maximum translational order parameter is located outside the line of diffusivity extrema that is enclosing the temperature of maximum density line. We compare our results with the monomeric system showing that the anisotropy due to the dumbbell leads to a much larger solid phase and to the appearance of a liquid crystal phase.