Background: Depending on the phase of the menstrual cycle the athlete is in, some kinetic, physiological and fatigue variables will show differences. The aim of this study is to analyze whether there are changes in these variables over the course of the menstrual cycle. Methods: Eight regular female runners and triathletes performed a maximal treadmill test, as well as a submaximal test (6’ stages at 50%, 60% and 80% of maximal aerobic speed) in each of the phases of the menstrual cycle: bleeding phase (day 2.4 ± 0.7), follicular phase (day 10.4 ± 2.2) and luteal phase (day 21.8 ± 2.1). Running dynamics were measured (using RunScribe) at the end of each test, as were lactate concentration, heart rate and fatigue (evaluated on a scale of 0 to 5). Results: Higher shock (G) values were recorded in the bleeding phase and higher vertical spring stiffness (kN/m) in the follicular phase. The phase of the menstrual cycle had a significant effect on average and peak heart rate, which was significantly higher in the follicular phase. Conclusions: Higher vertical spring stiffness was observed in the follicular phase, as well as higher peak and average heart rate.

Background: The respiratory syncytial virus infection (RSV) spread has been unusually high during 2022 and increasing trends have been documented We aimed to assess the survival experience of children hospitalized due bronchiolitis by laboratory-confirmed RSV. Methods: A nationwide and retrospective cohort was conducted in Mexico and data from 436 children aged 5 years and younger, with symptoms onset from August 2021 to November 2022, were analyzed. Survivor functions and 95% confidence intervals (CI) were computed by using the Kaplan-Meier method. Results: The survival rates were high, particularly within the first three weeks of admission. The 3-day survival was 99.8% (CI 95% 98.4-99.9%) and went to 98.9% (CI 95% 96.5-99.7%), 97.5% (CI 95% 91.9-99.3%), 86.7% (95% CI 48.2-97.2%), and 69.4% (95% CI 24.2-91.0%) on days 7, 14, 21 and 28 of hospital stay, respectively. We documented 5 fatal outcomes, and the mortality rate was 2.1 per 1,000 person-days. Conclusions: We analyzed a large set of pediatric patients with bronchiolitis by RSV and the presented results contribute to achieving a better understanding of the in-hospital evolution of this disease.

Background: Repeated SARS-CoV-2 infections are plausible and related published data are scarce. We aimed to identify factors associated with the risk of recurrent (three episodes) laboratory-confirmed symptomatic SARS-CoV-2 infections. Methods: A retrospective cohort study was conducted and 1,700 healthcare workers were enrolled. We used risk ratios (RR) and 95% confidence intervals (CI) to evaluate factors associated with symptomatic SARS-CoV-2 infections. Results: We identified 14 participants with recurrent illness episodes. Therefore, the incidence rate was 8.5 per 10,000 person-months. In multiple model, vaccinated adults (vs. unvaccinated, RR = 1.05 [1.03 - 1.06]) and those with a severe first illness episode (vs mild disease, RR = 1.05 [1.01 - 1.10]) were at increased risk for repeated symptomatic SARS-CoV-2 reinfections. Increasing age showed a protective effect (per each additional year of age: RR = 0.98 [0.97 - 0.99]). Conclusions: Our results suggest that recurrent SARS-CoV-2 infections are rare events in adults and they seem to be determined, partially, by vaccination status and age.