Carnosine in health and disease

Abstract

Carnosine was originally discovered in skeletal muscle, where it exists in larger amounts than in other tissues. The majority of research into the physiological roles of carnosine have been conducted on skeletal muscle. Given this and the potential for muscle carnosine content to be increased with supplementation, there is now a large body of research examining the ergogenic effects (or otherwise) of carnosine. More recent research, however, points towards a potential for carnosine to exert a wider range of physiological effects in other tissues, including the brain, heart, pancreas, kidney and cancer cells. Taken together, this is suggestive of a potential for carnosine to have therapeutic benefits in health and disease, although this is by no means without complication. Herein, we will provide a review of the current literature relating to the potential therapeutic effects of carnosine in health and disease.     

Impact of sports participation on mortality rates among Brazilian adults

Objective: To analyze the possible dose-response association between components of sports participation (intensity, volume and previous engagement) and 4-year mortality rates among Brazilian adults.

Methods: 679 males and females (mean age among men = 66.7 ± 9.3 years old and mean age among women = 64.8 ± 8.9 years old) composed the study sample. Sports participation was assessed using Baecke’s questionnaire, which considers intensity, duration and previous engagement. Medical records were used to identify the cause of the death. Cox regression analysis was performed to determine the independent associations of exercise components and mortality.

Results: Participants that reported exercising at moderate-vigorous intensity (Moderate/vigorous: 4.1% versus None/light: 10.3% [p-value = 0.012]; HR = 0.42 [0.1 to 0.94)] and for more than four months (≥4 months: 5.3% versus <4 months: 10.2% [p-value = 0.038]; HR = 0.47 [0.24 to 0.94]) had lower mortality risk. The percentage of survival according to all-cause mortality was significantly higher for participants engaged in sports at moderate-vigorous intensity (p-value = 0.014), as well as for those engaged in sports for periods superior than four months (p-value = 0.036).

Conclusion: We found higher percentage of survival among adults engaged in sports at moderate-vigorous intensity and with at least four months of previous engagement.     

Paving the Olympic Dream: The Politics of the 2007 Pan-American Games in Rio de Janeiro

Abstract

The making of the 2007 Pan-American Games, held in the city of Rio de Janeiro, marked the beginning of the long transformation that this city would undergo in connection to sports mega-events. This paper revisits how the 2007 Pan-American Games were largely produced under the promise that its legacies, particularly the infrastructural ones, could be effectively mobilized in order to strengthen the chances of bringing the Olympics to Brazil for the first time. Whereas this rhetoric has proven somewhat successful in helping the city to secure the right to host the 2016 Olympics, the alleged connection between both events has shown to be much more limited than its proponents had initially advertized. In reality, most of the venues constructed for the Pan-American Games had to be thoroughly renovated for the Olympics, while some of them presented structural problems and/or failed to meet the standards imposed by international sports federations.     

Lower limb alignment characteristics are not associated with running injuries in runners: Prospective cohort study

There is conflicting evidence on the association between lower limb alignment characteristics and the incidence of running-related injury (RRI). Therefore, the primary aim of this study was to investigate the association between lower limb alignment characteristics and the incidence proportion of RRI in a convenience sample of recreational runners. A total of 89 recreational runners were included in this prospective cohort study. These participants had been running for at least six months and were injury-free at baseline. Lower limb alignment measurements were conducted in order to calculate lower limb discrepancy, Q-angle, subtalar angle and plantar index. All participants also answered a baseline and biweekly online surveys about their running routine, history of RRI and newly developed RRI over a period of 12 weeks. The prevalence of previous RRI and the 12-week incidence proportion of new RRI were calculated. Logistic regression analysis was performed to estimate the association between lower limb length discrepancy, Q-angle, subtalar angle and plantar ach index with the incidence proportion of RRI. The prevalence of previous RRI was 55.1% (n?=?49). The 12-week incidence proportion of new RRI was 27.0% (n?=?24). Muscle injuries and tendinopathies were the main types of RRI identified. The lower leg and the knee were the main anatomical regions affected. We did not find significant associations between lower limb length discrepancy, Q-angle, subtalar angle and plantar arch index and injury occurrence.     

Metaphors we’re colonised by? The case of data-driven educational technologies in Brazil

ABSTRACT

This article discusses issues concerning the spread of data-driven educational technologies in Brazil. Here, as elsewhere, educational technology continues to be promoted optimistically as the bearer of a panacea for historically-rooted social problems. Whilst some of these technologies have indeed contributed to important widening-participation programmes in the last two decades, widespread advocacy of technological ‘solutionism’, reflected in gradually stronger policy demands for efficiencies to be improved through ‘innovation’, has supported a relentless marketisation of the country’s educational systems. As transnational corporations position themselves to take control of key areas of these systems, threatening to restructure the whole sector, data-driven educational technologies provide the latest example in a series of ‘new’ ideas offered in an ever-expanding market. Based on the notion of ‘conceptual metaphors’, which encapsulate specific ways of perceiving, thinking and relating with the world, this article examines key metaphors underpinning discourses surrounding data-driven educational technologies in Brazil. In particular, the article analyses ways in which these specific metaphors may be promoting perspectives that ignore difference and obscure broader questions concerning education, thus contributing to the reproduction of previously existing problems and supporting new forms of colonisation.     

Improving Academic Performance of Sport and Exercise Science Undergraduate Students in Gross Anatomy Using a Near-Peer Teaching Program

Peer and near-peer teaching programs are common in medical undergraduate courses. However, there are no studies that have investigated the effectiveness of a near-peer teaching program on the academic performance of undergraduate students pursuing sport and exercise science coursework. This study was conducted to analyze the effectiveness of such a program for students who participated in a course on the functional anatomy of the locomotor apparatus. A total of 39 student participants were divided into two groups: students in one group voluntarily attended at least one session of a near-peer teaching program, and students in the other group attended no sessions. The final grade (range 0–100%) was recorded and used as an indicator of academic performance. The final grade of students who attended the near-peer teaching program (69.5 ± 16.0%) was 38.7% higher (P = 0.002, d = 1.06) than those who did not (50.1 ± 20.4%). When the academic performance of the same students was evaluated in another course (exercise physiology) that did not offer a near-peer teaching program, there were no significant differences between the groups (students who attended or did not attend the near-peer teaching program). A significant positive association was found between near-peer teaching program frequency and the number of students approved and not approved in the course (P = 0.041). A significant difference (P = 0.001) was found in the attendance at regular classes between the group who participated in the near-peer teaching program (median: 62 hours; IQR [interquartile ranges]: 4.0 hours) and those who did not (median: 58 hours; IQR: 4.0 hours). Gender was not a moderating factor on academic performance or near-peer teaching program attendance. These results highlight the effectiveness of a near-peer teaching program on the academic performance of students from a sport and exercise science degree program while enrolled in an anatomy course. Anat Sci Educ. © 2018 American Association of Anatomists.     

Aerobic fitness and physical activity are inversely associated with body fat,dyslipidemia and inflammatory mediators in children and adolescents living with HIV

This study aimed to investigate if moderate to vigorous physical activity (MVPA) and aerobic fitness are associated with cardiovascular risk factors in HIV+ children and adolescents. Sixty-five children and adolescents (8 to 15 years) provided minutes of MVPA measured by accelerometers and peak oxygen uptake (peak VO₂) by breath-by-breath respiratory exchange. Cardiovascular risk factors were characterized by body fat, blood pressure, total cholesterol, HDL-c, LDL-c, triglycerides, glucose, insulin, C-reactive protein (CRP), interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α) and carotid intima-media thickness. Results indicated that higher MVPA was associated with lower values of total (β = ?3.566) and trunk body fat (β = ?3.495), total cholesterol (β = ?0.112) and LDL-c (β = ?0.830). Likewise, higher peak VO₂ was associated with lower total (β = ?0.629) and trunk body fat values (β = ?0.592) and levels of CRP (β = ?0.059). The physically active participants had lower total cholesterol (?24.4 mg.dL^?1) and LDL-c (?20.1 mg.dL^?1) compared to participants judged to be insufficiently active. Moreover, participants with satisfactory peak VO? showed lower total (?4.1%) and trunk (?4.3%) body fat, CRP (?2.3 mg.L^?1), IL-6 (?2.4 pg.mL^?1) and TNF-α (?1.0 pg.mL^?1) compared to low peak VO₂ peers. High levels of MVPA and aerobic fitness may prevent developing of cardiovascular risk factors in children and adolescents HIV+.     

Effects of Different Chair-Based Exercises on Salivary Biomarkers and Functional Autonomy in Institutionalized Older Women

Purpose: The aim of this study was to test the effects of chair-based exercise programs on salivary stress hormones, physical fitness, and functional autonomy of institutionalized older women. Method: In total, 47 participants (80 ± 8.04 years old) were recruited and allocated into three groups: chair-based aerobic exercises (CAE, n = 19), chair-based elastic-band strength exercises (CSE, n = 15), and a control group (CG, n = 13). A 14-week exercise intervention was done for the CAE and CSE groups, two times per week, in no consecutive days. Members of the CG did not participate in any type of exercise but kept their regular lifestyle. Fear of falling, autonomy, physical fitness, salivary cortisol, and alpha-amylase levels were assessed before and after the intervention. Results: The CAE group improved upper and lower body strength, agility–dynamic balance, and autonomy, with fear of falling decreasing significantly (p < .05, moderate effect size). Both exercise groups showed a trend toward an increase in salivary alpha-amylase levels (CAE = 43%, d = .31, and CSE = 44%, d = .41). Conclusion: Both exercise programs were able to improve functional autonomy, even in elders older than 80 years of age. It might be interesting to investigate the effectiveness of combining both aerobic and strength exercises in a unique protocol. The modulation effect of exercise in the hormonal responses needs to be further explored.     

Correlations between serum and salivary hormonal concentrations in response to resistance exercise

The aim of present study was to examine the relationships between serum and salivary values of free testosterone, dehydroepiandrosterone, and cortisol before and after a session of resistance exercise. Twenty-eight healthy men (mean age 40 years, s = 4) participated in the present study. Serum and salivary samples were collected at rest and after a multiple-sets resistance exercise protocol, of approximately 25 minutes duration. Concentrations of free testosterone, dehydroepiandrosterone, and cortisol were measured using radioimmunoassay kits. No significant correlation was observed between serum free testosterone and salivary testosterone (r = 0.22 to 0.26, P > 0.05). Serum cortisol was significantly correlated with salivary cortisol before (r = 0.52, P = 0.005) and after (r = 0.62, P = 0.001) the exercise protocol. Serum and salivary concentrations of dehydroepiandrosterone were significantly correlated before (r = 0.68, P < 0.001) and after (r = 0.7, P < 0.001) exercise. The results of the present study suggest that even under exercise conditions, the salivary values of cortisol and dehydroepiandrosterone can reflect the behaviour of these hormones in blood. However, further studies are necessary to verify if salivary testosterone reflects the behaviour of serum free testosterone during resistance exercise.     

Resting Bradycardia,Enhanced Postexercise Heart Rate Recovery and Cardiorespiratory Fitness in Recreational Ballroom Dancers

Purpose: In a cross-sectional study design, we evaluated the resting heart rate (HR_baseline) and exercise and postexercise stress test-related chronotropic responses in male practitioners of recreational ballroom dancing (BD; n = 25, M_age = 26.6 ± 6.1 years) compared to a control group of insufficiently active nondancers (CG; n = 25, M_age = 25.9 ± 4.5 years). Method: All participants underwent a submaximal exercise test. At 85% of the maximal predicted HR, the recovery protocol was started, and heart rate recovery (HRR) was recorded during 1-min intervals for 5 min. Results: Compared with CG, BD showed lower HR_baseline (70 beats per minute [bpm] vs. 62 bpm, respectively, U = 143, p < .05, ES = .46), lower preexercise HR (94 bpm vs. 86 bpm, U = 157, p < .05, ES = .42), longer exercise test duration (346 s vs. 420 s, U = 95.5, p < .05, ES = .59), and higher HRR for 5 min postexercise (U = 1.29–1.89, p < .05, ES = .33–.50) as follows: 1st min (32 bpm vs. 40 bpm), 2nd min (45 bpm vs. 53 bpm), 3rd min (51 bpm vs. 58 bpm), 4th min (55 bpm vs. 59 bpm), and 5th min (59 bpm vs. 63 bpm). The coefficient of HRR from the 1st min to the 5th min postexercise was similar in both groups (U = 229–311, p > .05, ES = < .10–.22). Conclusion: Heightened cardiovascular functional status characterized by favorable enhanced chronotropic dynamics appears to occur in practitioners of recreational ballroom dancing, which suggests that this modality of exercise may result in health benefits.