RESUMO
Creatine and sodium bicarbonate supplementation independently increase exercise performance, but it remains unclear whether combining these 2 supplements is more beneficial on exercise performance. The purpose of this study was to evaluate the impact of combining creatine monohydrate and sodium bicarbonate supplementation on exercise performance. Thirteen healthy, trained men (21.1 ± 0.6 years, 23.5 ± 0.5 kg·m(-2), 66.7 ± 5.7 ml·(kg·m)(-1) completed 3 conditions in a double-blinded, crossover fashion: (a) Placebo (Pl; 20 g maltodextrin + 0.5 g·kg(-1) maltodextrin), (b) Creatine (Cr; 20 g + 0.5 g·kg(-1) maltodextrin), and (c) Creatine plus sodium bicarbonate (Cr + Sb; 20 g + 0.5 g·kg(-1) sodium bicarbonate). Each condition consisted of supplementation for 2 days followed by a 3-week washout. Peak power, mean power, relative peak power, and bicarbonate concentrations were assessed during six 10-second repeated Wingate sprint tests on a cycle ergometer with a 60-second rest period between each sprint. Compared with Pl, relative peak power was significantly higher in Cr (4%) and Cr + Sb (7%). Relative peak power was significantly lower in sprints 4-6, compared with that in sprint 1, in both Pl and Cr. However, in Cr + Sb, sprint 6 was the only sprint significantly lower compared with sprint 1. Pre-Wingate bicarbonate concentrations were significantly higher in Cr + Sb (10%), compared with in Pl and Cr, and mean concentrations remained higher after sprint 6, although not significantly. Combining creatine and sodium bicarbonate supplementation increased peak and mean power and had the greatest attenuation of decline in relative peak power over the 6 repeated sprints. These data suggest that combining these 2 supplements may be advantageous for athletes participating in high-intensity, intermittent exercise.
Assuntos
Creatina/uso terapêutico , Corrida/fisiologia , Bicarbonato de Sódio/uso terapêutico , Adolescente , Adulto , Análise de Variância , Estudos Cross-Over , Suplementos Nutricionais , Método Duplo-Cego , Teste de Esforço , Frequência Cardíaca/fisiologia , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Reprodutibilidade dos Testes , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Patellofemoral Pain Syndrome (PFPS), a common cause of anterior knee pain, is successfully treated in over 2/3 of patients through rehabilitation protocols designed to reduce pain and return function to the individual. Applying preventive medicine strategies, the majority of cases of PFPS may be avoided if a pre-diagnosis can be made by clinician or certified athletic trainer testing the current researched potential risk factors during a Preparticipation Screening Evaluation (PPSE). We provide a detailed and comprehensive review of the soft tissue, arterial system, and innervation to the patellofemoral joint in order to supply the clinician with the knowledge required to assess the anatomy and make recommendations to patients identified as potentially at risk. The purpose of this article is to review knee anatomy and the literature regarding potential risk factors associated with patellofemoral pain syndrome and prehabilitation strategies. A comprehensive review of knee anatomy will present the relationships of arterial collateralization, innervations, and soft tissue alignment to the possible multifactoral mechanism involved in PFPS, while attempting to advocate future use of different treatments aimed at non-soft tissue causes of PFPS. METHODS: A systematic database search of English language PubMed, SportDiscus, Ovid MEDLINE, Web of Science, LexisNexis, and EBM reviews, plus hand searching the reference lists of these retrieved articles was performed to determine possible risk factors for patellofemoral pain syndrome. RESULTS: Positive potential risk factors identified included: weakness in functional testing; gastrocnemius, hamstring, quadriceps or iliotibial band tightness; generalized ligamentous laxity; deficient hamstring or quadriceps strength; hip musculature weakness; an excessive quadriceps (Q) angle; patellar compression or tilting; and an abnormal VMO/VL reflex timing. An evidence-based medicine model was utilized to report evaluation criteria to determine the at-risk individuals, then a defined prehabilitation program was proposed that begins with a dynamic warm-up followed by stretches, power and multi-joint exercises, and culminates with isolation exercises. The prehabilitation program is performed at lower intensity level ranges and can be conducted 3 days per week in conjunction with general strength training. Based on an objective one repetition maximum (1RM) test which determines the amount an individual can lift in good form through a full range of motion, prehabilitation exercises are performed at 50-60% intensity. CONCLUSION: To reduce the likelihood of developing PFPS, any individual, especially those with positive potential risk factors, can perform the proposed prehabilitation program.
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To investigate whether socioeconomic status (SES) and acculturation predict overweight/obesity risk as well as the mediating effect of physical activity (PA) in the context of internal migration. Cross-sectional study of 587 rural-to-urban migrants participating in the PERU MIGRANT study. Analyses were conducted using logistic regression and structured equation modeling. Interaction effects of SES and acculturation were tested. Models were controlled for age, gender and education. Only SES was a significant predictor of overweight/obesity risk. Lower SES decreased the odds of being overweight/obese by 51.4 %. This association did not vary by gender nor was it explained by PA. Mechanisms underlying the relationship between SES and overweight/obesity may differ depending on the geographic location and sociocultural context of the population studied. Research on internal migration and health would benefit from the development of tailored acculturation measures and the evaluation of exploratory models that include diet.
Assuntos
Aculturação , Migração Humana , Sobrepeso/epidemiologia , Adulto , Índice de Massa Corporal , Estudos Transversais , Dieta , Exercício Físico , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Peru/epidemiologia , Fatores de Risco , Fatores Sexuais , Classe SocialRESUMO
OBJECTIVE: To describe novel C-reactive protein (CRP) molecular forms (mf) in human plasma. DESIGN AND METHODS: Five novel CRP-mfs, disctinct from the previously described native (nCRP) and modified (mCRP) C-reactive proteins, were separated from human plasma by polyacrylamide gel electrophoresis and immunodetected by western blot in subjects with or without increased BMI, cardiovascular disease (CVD), and diabetes (nâ=â1800). RESULTS: Three of the five CRP-mfs were present in all samples. One, CRPmf-4, was present in a subgroup of subjects and its presence was associated with elevated body mass index (BMI). CRP-mf-5 was present in about 2% of the subjects and was not associated with any other parameters. The presence or distribution of the 5 CRP-mfs were not Ca2+-dependent. Crossed immuno-localization experiments indicated that none of the CRP-mfs were complexed with any of the lipoprotein classes or with signature proteins of the complement-factor. Moreover, the distribution of CRP-mfs were not significantly correlated with plasma CRP levels. CRP-mf-4 was significantly associated with increased BMI, but not with other parameters of the metabolic syndrome (HDL-C and triglyceride levels, and diabetes). CONCLUSIONS: We have identified five new CRP-mfs out of which CRP-mf-4 was significantly associated with obesity. We have shown that oligomerization of CRP was not calcium dependent. We hypothesize that adipose tissue produces a factor which influences the formation of CRP mf-4. CRP-mfs might be used as an obesity-associated inflammatory marker.
Assuntos
Proteína C-Reativa/metabolismo , Obesidade/sangue , Obesidade/metabolismo , Tecido Adiposo/metabolismo , Adulto , Idoso , Índice de Massa Corporal , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/metabolismo , Diabetes Mellitus/sangue , Diabetes Mellitus/metabolismo , Feminino , Humanos , Lipoproteínas/metabolismo , Masculino , Síndrome Metabólica/sangue , Pessoa de Meia-IdadeRESUMO
Although the U.S. federal government, the National Science Foundation, and other influential groups have called for American universities to educate and train more scientists, a recent article in the Washington Post and broadcasting on National Public Radio affirmed a harsh reality: there are too few jobs for today's young scientists. Essentially, landing a job in science doesn't just happen, you must prepare! The intent of this education track session, targeted to students, postdoctorates, junior faculty, and other early- to midcareer professionals was to provide insights on trends in the current job market and offer strategies and resources to be competitive. The session featured speakers representing different work environments, such as academia, industry, health care institutions, public relations, and entrepreneurial positions.
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Comércio , Emprego , Ciência , Universidades , HumanosRESUMO
Our purpose was to examine the effects of age and gender on physical performance. We assessed a one-hour swimming performance and participation of 4,271 presumably healthy men and women, aged 19-91 years, from the 2001-2003 United States Masters Swimming long-distance (1 h) national competition. The decline in performance with increasing age was found to be quadratic rather than linear. The equation which best fit variation in 1 h swimming distance in meters (m) according to variations in age in years (y) in men was: distance (m) = 4058 + 2.18 age-0.29 age (http://www.acsmmsse.org/pt/re/msse/positionstandards.htm;jsessionid=DiRVACC7YS3mq27s5kV3vwpEVSokmmD1ZJLC7pdnol3KcfoSu0t!1096311956!-949856145!9001!-1), with the same equation for women except that 380 m needed to be subtracted from the calculated value at all ages (about a 10% difference). There was a large overlap in performance between men and women. The overall mean decline in performance with age was about 50% and was parallel in men and women. The mean difference in distance for a 1-year increment in age was -9.7 m at 21 y of age, -21.3 m at 40 y, and -44.5 m at 80 y. Far greater declines of about 96% in numbers participating with advanced age (80 y and over, 4% of peak numbers) were observed than in the 40-49 y age group. In conclusion, the declines in performance were parallel in men and women at all ages, and the 1-year age-related declines in performance were about twice as great at 40 y and more than four-times as great at 80 y than at 20 y of age, with even greater age-related declines in participation being noted for both men and women.
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OBJECTIVE: To compare oxandrolone (OX) or strength training with nutrition alone (NA) for AIDS wasting. SUBJECTS: Fifty patients with AIDS; 47 completing the study. INTERVENTIONS: Randomization to (1) NA with placebo pills, (2) nutrition with 10 mg of OX administered orally twice a day, or (3) nutrition with progressive resistance training (PRT) for 12 weeks. MAIN OUTCOME MEASURES: Midthigh cross-sectional muscle area (CSMA), physical functioning (PF), costs, and cost-effectiveness in dollars/quality-adjusted life-years (dollars/QALYs). RESULTS: The OX and PRT subjects had increases in CSMA (7.0% +/- 2.5%, P = 0.01; 5.0% +/- 2.0%, P = 0.04, respectively), although these increases did not differ significantly from the NA arm (NA: 1.0% +/- 1.0%; OX vs. NA: P = 0.09; PRT vs. NA: P = 0.26). Only PRT caused significant improvements in PF (mean +/- SE: 10.4 +/- 3.8 points on a 100-point scale) and 7 measures of strength (P values: 0.04 to <0.001). There were no overall differences between groups in PF change. Among patients with impaired baseline PF, however, OX was significantly less effective than NA and PRT was significantly better than NA. All treatments led to increases in protein intake and performance; NA and PRT also increased caloric intake. The institutional costs per subject in this trial were 983 dollars for NA, 3772 dollars for OX, and 3189 dollars for PRT. At a community-based level of intensity, the institutional costs per QALY were 45,000 dollars (range: 42,000 dollars-64,000 dollars) for NA, 147,000 dollars (range: 147,000 dollars-163,000 dollars) for OX, and 31,000 dollars (range: 21,000 dollars-44,000 dollars) for PRT. CONCLUSIONS: OX and PRT induce similar improvements in body composition, but PRT improves quality of life more than nutrition or OX, particularly among patients with impaired PF. PRT was the most cost-effective intervention, and OX was the least cost-effective intervention.