Rafael Pereira

Effect of varying rest intervals between sets of assistance exercises on creatine kinase and lactate dehydrogenase responses.

Machado, M, Koch, AJ, Willardson, JM, Pereira, LS, Cardoso, IM, Motta, MKS, Pereira, R, and Monteiro, AN. Effect of varying rest intervals between sets of assistance exercises on creatine kinase and lactate dehydrogenase responses. J Strength Cond Res 25(5): 1339-1345, 2011-To examine the effects of different rest intervals between sets on serum creatine kinase (CK) and lactate dehydrogenase (LDH) activity, 10 men (age = 25.6 ± 2.2 years, height = 173.1 ± 7.1 cm, and body mass = 75.9 ± 10.0 kg) participated in a randomized within-subject design that involved 4 resistance exercise sessions. Each session consisted of 4 sets of 10 repetitions with 10 repetition maximum loads for the chest press, pullover, biceps curl, triceps extension, leg extension, and prone leg curl. The sessions differed only in the length of the rest interval between sets and exercises, specifically: 60, 90, 120, 180 seconds. Serum CK and LDH were significantly (p < 0.05) elevated 24-72 hours after each session, with no significant differences between rest intervals (p = 0.94 and p = 0.99, respectively). The mechanical stress imposed by the 4 resistance exercise sessions invoked similar damage to the muscle fibers independent of the rest interval between sets. These data indicate that the accumulated volume of work is the primary determinant of muscle damage in trained subjects who are accustomed to resistance exercise with short rest intervals.

Short intervals between sets and individuality of muscle damage response.

Abstract Machado, M, Pereira, R, and Willardson, JM. Short intervals between sets and individuality of muscle damage response. J Strength Cond Res 26(11): 2946–2952, 2012—This study examined creatine kinase (CK) activity after resistance exercise sessions in subjects classified as high (HiR), medium (MeR), or low responders (LoR). Two resistance exercise sessions were performed that each involved 4 sets of the biceps curl at 85% of a 1 repetition maximum (1RM) and either 1- or 3-minute rest intervals between sets. High responders and MeR demonstrated significantly greater CK activity after the 1-minute session vs. the 3-minute session. Therefore, the HiR and MeR subjects exhibited less tolerance to resting 1 minute between sets, whereas the CK activity was not significantly different between rest intervals for the LoR subjects. The application of these findings indicates the need to vary the length of the rest interval between sets with the understanding that individuals exhibit varying recuperative abilities and some might be less tolerant of shorter rest intervals between sets.

Association between social support and quality of life of relative caregivers of elderly dependents

OBJECTIVE to ascertain the association between the social support and the quality of life of relative caregivers of elderly dependents at home. METHOD a cross-sectional study conducted with 58 relative caregivers of elderly dependents, registered in the Family Health Strategy. Data were collected from the Katz instrument, sociodemographic, Zarit Burden Interview, WHOQOL-bref, and analyzed using descriptive statistics and multiple linear regression. RESULTS the majority of caregivers were women, who took care full-time and presented moderate to severe burden. Most caregivers are satisfied with their social relationships and the social support received. It is found that the burden and the time of care correlated with the social relationships domain, which is associated with social support, and consequently, reduced quality of life. CONCLUSION social support for caregivers is important to prevent health implications, burden, biopsychosocial stress, and provide favorable conditions for quality of life, by allowing greater freedom to develop their daily activities.

Creatine supplementation: effects on blood creatine kinase activity responses to resistance exercise and creatine kinase activity measurement

The purpose of this study was to determine the effects of creatine supplementation and exercise on the integrity of muscle fiber, as well as the effect of the supplementation on the creatine kinase (CK) assay measurement. Forty-nine sedentary individuals participated in a double-blind study and were divided into two groups: C (n=26) received 4x5-day packages of 0.6 g.kg-1 of body weight contained 50% of creatine + 50% of dextrose, and P (n=23) received packages containing only dextrose. On the first day the groups performed a 1RM test for bench press, seated row, leg extension, leg curl and leg press. On D7 they received the supplements. On the fourteenth day, they performed a training session of five exercises, each in three sets of ten repetitions at 75% of 1RM. Blood was collected before (D14) and after the exercise session (D15). Differing levels of blood creatine were tested to determine the influence on the assay measurements of CK. ANOVA and Tukeys post-hoc tests were used to compare groups and different times of study protocol (P<0.05). No changes were observed in CK activity of the groups from D0, D7 and D14. On D15 CK activity increases 140% (women) and 200% (men). There was no difference in CK activity between groups. Blood creatine levels up to 5mM produced no significant effect on CK assay results. CK activity increased after resistance exercise, while creatine supplementation produced no difference in the muscle cellular integrity nor compromised assay methodology.

Reliability analysis of the heart autonomic control parameters during hemodialysis sessions.

Abstract The study of heart autonomic control (HAC) in patients with chronic kidney disease (CKD) undergoing dialysis treatment has been carried out, however, there are no studies reporting the reliability of measurements of HAC parameters involving the mentioned samples and conditions. The reliability of many HAC parameters was evaluated from patients with CKD during two sessions of hemodialysis. The successive R-R intervals were recorded during two sessions of hemodialysis from 14 CKD patients that were undergoing dialysis for at least 6 months and with no history of recurrent hypotensive events. HAC parameters were obtained with time and frequency domain analysis, as well as with nonlinear methods. The reliability was measured with the intraclass correlation coefficient (ICC). The results showed excellent reliability (ICC=0.90–0.98) for most heart rate variability (HRV) parameters, especially the parameters obtained in the time domain [square root of the mean squared differences between successive R-R intervals (RMSSD), percentage of adjacent R-R intervals that differ by more than 50 ms (pNN50), mean of the 5-min standard deviations of R-R intervals (SDNNi), and triangular index] and with non-linear methods [standard deviation of the instantaneous variability beat-to-beat (SD1), standard deviation in long-term continuous R-R intervals (SD2), detrended fluctuation analysis (DFA) α1 and α2, approximate and sample entropies, and correlation dimension (D2): ICC=0.86–0.96]. Among the parameters obtained in the frequency domain (normalized magnitude from the spectrum of low-frequency components (LFnu), normalized magnitude from the spectrum of high-frequency components (HFnu), and LF/HF ratio), the LF/HF ratio showed better reliability (ICC=0.96 vs. ICC=0.70). Measurements of HAC parameters have excellent test-retest reliability for the studied samples and conditions.

The Short and Long Term Effects of Tibialis Anterior Local Cooling on Dorsiflexion Force

The Short and Long Term Effects of Tibialis Anterior Local Cooling on Dorsiflexion Force The goal of this study was to analyze and compare the superficial temperature, dorsiflexion force and electromyographic (EMG) signal of tibialis anterior muscle before and after superficial cooling application. Seventeen healthy untrained volunteers were divided into two groups. Subjects were submitted to seven procedures of maximal voluntary isometric contractions of dorsiflexion, once before and six times after thirty minutes of either superficial cooling of the anterolateral side of the leg with an ice pack (LC group) or rest (control group). Superficial temperature, dorsiflexion force and EMG of the tibialis anterior muscle were evaluated immediately, 5, 15, 30, 45 and 60 minutes after cooling intervention. The results showed that the superficial temperature reduced significantly for 60 minutes post cooling, dorsiflexion force and amplitude of EMG signal was reduced only immediately after cooling application, whereas median frequency of EMG signal was significantly reduced up to 60 minutes post cooling application. The study concludes that superficial cooling with ice pack for thirty minutes can decrease the dorsiflexion force and EMG activity only immediately after the cooling application, while it causes a prolonged decrement on the superficial local temperature and on the median frequency of the EMG signal. These findings suggest that clinicians should be aware of the immediately alterations in motor output performance that result from muscle local cooling interventions which are followed by rapid recovery.

Quality of life of relative caregivers of elderly dependents at home

The objective of this study was to analyze the relationship of sociodemographic characteristics and activity overload with the quality of life of relative caregivers of elderly dependents at home. This is an epidemiological, transversal study, conducted with 58 relative caregivers of elderly people registered in Family Health Programs in a municipality in the state of Bahia. Sociodemographic data were collected; in addition, the Katz Index of Independence, Zarit Burden Interview, and WHOQOL-bref were administered. The data were analyzed using correlation and multiple linear regression. The Zarit scale was negatively associated with all areas of the WHOQOL-bref domain, which was corroborated by the multiple regression model, which identified that the Zarit scale alone was able to predict the impact of care on quality of life of the studied caregivers. There is evidence of a need for expansion of social and health support to caregivers in an attempt to minimize overload, improving the quality of life of these individuals. DESCRIPTORS: Caregivers. Family. Aged. Quality of life. Social support.The objective of this study was to analyze the relationship of sociodemographic characteristics and activity overload with the quality of life of relative caregivers of elderly dependents at home. This is an epidemiological, transversal study, conducted with 58 relative caregivers of elderly people registered in Family Health Programs in a municipality in the state of Bahia. Sociodemographic data were collected; in addition, the Katz Index of Independence, Zarit Burden Interview, and WHOQOL-bref were administered. The data were analyzed using correlation and multiple linear regression. The Zarit scale was negatively associated with all areas of the WHOQOL-bref domain, which was corroborated by the multiple regression model, which identified that the Zarit scale alone was able to predict the impact of care on quality of life of the studied caregivers. There is evidence of a need for expansion of social and health support to caregivers in an attempt to minimize overload, improving the quality of life of these individuals. DESCRIPTORS: Caregivers. Family. Aged. Quality of life. Social support.

Associação entre aspectos psicossociais do trabalho e qualidade de vida de mototaxistas

This study aimed to evaluate the quality of life of motorcycle taxi drivers and the association with psychosocial characteristics of their work. This was a cross-sectional epidemiological study with a sample of 400 motorcycle taxi drivers in Jequié, Bahia State, Brazil. The study used a form containing demographic and socioeconomic data, WHO Quality of Life-Bref Questionnaire (WHOQOL-Bref), and the Job Content Questionnaire (JCQ). Motorcycle taxi drivers with greater decision-making control over their work showed better self-rated quality of life in the psychological domain; those with high psychological demands presented better self-rated quality of life in the social relations and environmental domains; those with high strain and active work showed better self-rated quality of life in the social and environmental domains. The psychosocial work environment and especially decision-making autonomy were thus important determinants of self-rated quality of life in this group of motorcycle taxi drivers.Este estudio tuvo como objetivo evaluar la calidad de vida de los mototaxistas y su relacion con los aspectos psicosociales del trabajo. Estudio epidemiologico, transversal, realizado con 400 mototaxistas del municipio de Jequie, Bahia, Brasil. Se utilizo un formulario con datos sociodemograficos, el WHO Quality of Life-Bref Questionnaire (WHOQOL-Bref) y el Job Content Questionnaire (JCQ). Los resultados evidenciaron que los mototaxistas con un alto control de trabajo presentaron mejor percepcion de la calidad de vida en el dominio psicologico; aquellos con una alta demanda psicologica tuvieron mejor percepcion de calidad de vida en los dominios de relaciones sociales y el medio ambiente; aquellos con alta exigencia y trabajo activo mostraron mejor percepcion de la calidad de vida en los dominios de relaciones sociales y medio ambiente. Asi, el ambiente psicosocial del trabajo y, especialmente, el control sobre el trabajo son determinantes importantes para la percepcion de la calidad de vida de los mototaxistas.

QUALIDADE DE VIDA DE CUIDADORES FAMILIARES DE IDOSOS DEPENDENTES NO DOMICÍLIO

The objective of this study was to analyze the relationship of sociodemographic characteristics and activity overload with the quality of life of relative caregivers of elderly dependents at home. This is an epidemiological, transversal study, conducted with 58 relative caregivers of elderly people registered in Family Health Programs in a municipality in the state of Bahia. Sociodemographic data were collected; in addition, the Katz Index of Independence, Zarit Burden Interview, and WHOQOL-bref were administered. The data were analyzed using correlation and multiple linear regression. The Zarit scale was negatively associated with all areas of the WHOQOL-bref domain, which was corroborated by the multiple regression model, which identified that the Zarit scale alone was able to predict the impact of care on quality of life of the studied caregivers. There is evidence of a need for expansion of social and health support to caregivers in an attempt to minimize overload, improving the quality of life of these individuals. DESCRIPTORS: Caregivers. Family. Aged. Quality of life. Social support.The objective of this study was to analyze the relationship of sociodemographic characteristics and activity overload with the quality of life of relative caregivers of elderly dependents at home. This is an epidemiological, transversal study, conducted with 58 relative caregivers of elderly people registered in Family Health Programs in a municipality in the state of Bahia. Sociodemographic data were collected; in addition, the Katz Index of Independence, Zarit Burden Interview, and WHOQOL-bref were administered. The data were analyzed using correlation and multiple linear regression. The Zarit scale was negatively associated with all areas of the WHOQOL-bref domain, which was corroborated by the multiple regression model, which identified that the Zarit scale alone was able to predict the impact of care on quality of life of the studied caregivers. There is evidence of a need for expansion of social and health support to caregivers in an attempt to minimize overload, improving the quality of life of these individuals. DESCRIPTORS: Caregivers. Family. Aged. Quality of life. Social support.

Handgrip explosive force is correlated with mobility in the elderly women.

The analysis of explosive force, through rate of force development (RFD) and contractile impulse (CI), from handgrip strength data seems to be useful and promising information to study the aging of musculoskeletal system and health status. We aimed to test the hypothesis that, in elderly women, the handgrip explosive force could be better associated to the functional mobility than maximum handgrip strength. Handgrip strength and the performance of Timed Up & Go Test (TUG) were measured from sixty-five community-dwelling healthy elderly women. The average slope of the moment-time curve (Δ moment/Δ time) over the time interval of 0-200 ms relative to the onset of contraction was calculated to provide the RFD and CI. The highest strength achieved during the isometric contraction was used as maximum handgrip strength. Pearson correlations were used to assess the strength of the relationship between the handgrip strength parameters (Maximum strength and explosive force from 0-200 ms) and TUG test performance from older women. The correlation analysis showed that the TUG test performance was inversely correlated to the handgrip strength parameters, with better relationship with explosive force parameters. The handgrip explosive force seems to be a promising predictor of functional mobility of elderly women, since it showed a better relationship with functional mobility than maximum handgrip strength.