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Aim: To investigate the association between physical activity and immunogenicity among SARS-CoV-2 seropositive patients with autoimmune rheumatic diseases prior to and following a 2-dose schedule of CoronaVac (Sinovac inactivated vaccine). Methods: This was a prospective cohort study within an open-label, single-arm, phase 4 vaccination trial conducted in Sao Paulo, Brazil. In this substudy, only SARS-CoV-2 seropositive patients were included. Immunogenicity was assessed by seroconversion rates of total anti-SARS-CoV-2 S1/S2 immunoglobulin G (IgG), geometric mean titers of anti-S1/S2 IgG, frequency of positive neutralizing antibodies, and neutralizing activity before and after vaccination. Physical activity was assessed through a questionnaire. Model-based analyses were performed controlling for age (<60 or ≥60 y), sex, body mass index (<25, 25–30, and >30 kg/m2), and use of prednisone, immunosuppressants, and biologics. Results: A total of 180 seropositive autoimmune rheumatic disease patients were included. There was no association between physical activity and immunogenicity before and after vaccination. Conclusions: This study suggests that the positive association between physical activity and greater antibody responses seen in immunocompromised individuals following vaccination is overridden by previous SARS-CoV-2 infection, and does not extend to natural immunity. [ABSTRACT FROM AUTHOR]

β-Alanine (BA) is one of the most widely used sport supplements, due to its capacity to improve high-intensity exercise performance by increasing muscle carnosine (MCarn) content, and consequently, the buffering capacity of the muscle. BA is also available in a variety of animal foods, but little is currently known about the influence of dietary BA intake on MCarn. The aim of the current study was to compile a detailed summary of available data on the BA content of commonly consumed foods, and to explore whether associations could be detected between self-reported dietary BA intake and skeletal MCarn in a group of 60 healthy, active, omnivorous men and women. Dietary BA intake was assessed via 3-day food records, and MCarn content assessed by high-performance liquid chromatography. A series of univariate and multivariate linear regression models were used to explore associations between estimated dietary BA and MCarn. No evidence of associations between dietary BA intake and MCarn were identified, with effect sizes close to zero calculated from models accounting for key demographic variables (f² ≤ 0.02 for all analyses). These findings suggest that capacity to increase MCarn via dietary strategies may be limited, and that supplementation may be required to induce increases of the magnitude required to improve performance. [ABSTRACT FROM AUTHOR]

Background: Physical activity associates with improved immunogenicity following a 2-dose schedule of CoronaVac (Sinovac's inactivated SARS-CoV-2 vaccine) in patients with autoimmune rheumatic diseases (ARD). This study evaluates whether physical activity impacts vaccine-induced antibody responses to a booster dose in this population. Methods: This was a phase-4 trial conducted in São Paulo, Brazil. Patients with ARD underwent a 3-dose schedule of CoronaVac. One month after the booster, we assessed seroconversion rates of anti-SARS-CoV-2 S1/S2 IgG, geometric mean titers of anti-S1/S2 IgG, frequency of positive neutralizing antibodies, and neutralizing activity. Physical activity was assessed through questionnaire. Results: Physically active (n = 362) and inactive (n = 278) patients were comparable for most characteristics; however, physically active patients were younger (P <.01) and had a lower frequency of chronic inflammatory arthritis (P <.01). Adjusted models showed that physically active patients had ∼2 times odds of seroconversion rates (OR: 2.09; 95% confidence interval, 1.22 to 3.61), ∼22% greater geometric mean titers of anti-S1/S2 IgG (22.09%; 95% confidence interval, 3.91 to 65.60), and ∼7% greater neutralizing activity (6.76%; 95% confidence interval, 2.80 to 10.72) than inactive patients. Conclusions: Patients with ARD who are physically active have greater odds of experiencing better immunogenicity to a booster dose of CoronaVac. These results support the recommendation of physical activity to improve vaccination responses, particularly for immunocompromised individuals. [ABSTRACT FROM AUTHOR]

This study quantified and compared the weekly locomotor activity and subjective load between elite and development loan youth soccer players registered to a primary club. Development loan players were loaned to a lower-league club and trained part-time with their loan club whilst being available for development fixtures and training with the primary club. Data were collected in 16 squad players and 4 development loan players at loan clubs across a 41 week competitive phase of the 2018/2019 season. Analysis was completed on total distance (m), PlayerLoadTM (au), low intensity running (<14.4 km·h−1, m), running (19.8–24.98 km·h−1, m), sprinting (>24.98 km·h−1, m), accelerations (>2 m·s−2 count) and decelerations (<−2 m·s−2, count). Point estimates for the development loan players consistently showed lower weekly values than squad players for all variables ranging from 5.2% (weekly sRPE) to 16.8% (weekly sprint distance covered). Differences, however, were not found to be statistically significant (p ≥ 0.07). Variance ranged from 23.6% (weekly distance) to 37.7% (weekly high-intensity accelerations). Although the goals of a development loan are likely to be multifactorial, this is the first study to quantify and compare locomotor activities and subjective loading of players within the development loan environment. [ABSTRACT FROM AUTHOR]

Many reports describe using a supramaximal verification phase—exercising at a power output higher than the highest power output recorded during an incremental cardiopulmonary test—to validate VO2max. The impact of verification phases on estimating the proportion of individuals who increased VO2peak in response to high-intensity interval training (HIIT) remains an underexplored area in the individual response literature. This analysis investigated the influence of same-day and separate-day verification phases during repeated measurements (incremental tests—INCR1 and INCR2; incremental tests + supramaximal verification phases—INCR1+ and INCR2+) of VO2peak on typical error (TE) and the proportion of individuals classified as responders (i.e., the response rate) following 4 weeks of HIIT (n = 25) or a no-exercise control period (n = 9). Incorporation of supramaximal verification consistently reduced the standard deviation of individual response, TE, and confidence interval (CI) widths. However, variances were statistically similar across all groups (p > 0.05). Response rates increased when incorporating either one (INCR1 to INCR1+; 24%–48%, p = 0.07) or two (INCR2 to INCR2+; 28%–48%, p = 0.063) supramaximal verification phases. However, response rates remained unchanged when either zero-based thresholds or smallest worthwhile difference response thresholds were used (50% and 90% CIs, all p > 0.05). Supramaximal verification phases reduced random variability in VO2peak response to HIIT. Compared with separate-day testing (INCR2 and INCR2+), the incorporation of a same-day verification (INCR1+) reduced CI widths the most. Researchers should consider using a same-day verification phase to reduce uncertainty and better estimate VO2peak response rate to HIIT. [ABSTRACT FROM AUTHOR]