Research Outputs
Relationship between heart rate variability, physical activity levels, and sociodemographic factors in young adults: cross-sectional study
Introduction: heart rate variability is a key indicator of cardiovascular health and autonomic balance, influenced by various factors such as age and stress. Objective: to relate heart rate variability to body composition, physical activity levels, sleep quality, and self-perceived stress in young Chilean adults with low cardiometabolic risk. Methodology: a cross-sectional study was conducted in 2024 with the participation of 32 young adults (18 to 30 years old), selected based on inclusion criteria related to adequate physical activity levels and the absence of chronic diseases. The analysis considered variables such as body composition, sleep quality, stress levels, physical activity levels, and heart rate variability, with the latter measured over a 5-minute resting period. Results: age showed a significant negative relationship with RMSSD (β = -0.43, t = -2.48, p = .02), indicating a decrease in parasympathetic activity as age increases. Self-perceived stress, however, did not show a significant impact on RMSSD (β = .09, p = .60) or the RR/RMSSD ratio (β = -0.37, p = .04). Discussion: the findings highlight the importance of heart rate variability as an indicator of autonomic health, emphasizing how age and stress impact vagal modulation. These results reinforce the need to integrate autonomic monitoring into preventive strategies to improve cardiovascular health. Conclusion: heart rate variability is significantly related to age and self-perceived stress. These findings underline the importance of integrating autonomic monitoring into preventive health strategies.
Only half of the authors of overviews of exercise-related interventions use some strategy to manage overlapping primary studies—a metaresearch study
Objectives: The conduct of systematic reviews (SRs) and overviews share several similarities. However, because the unit of analysis for overviews is the SRs, there are some unique challenges. One of the most critical issues to manage when conducting an overview is the overlap of data across the primary studies included in the SRs. This metaresearch study aimed to describe the frequency of strategies to manage the overlap in overviews of exercise-related interventions. Study Design and Setting: A systematic search in MEDLINE (Ovid), Embase (Ovid), Cochrane Library, Epistemonikos, and other sources was conducted from inception to June 2022. We included overviews of SRs that considered primary studies and evaluated the effectiveness of exercise-related interventions for any health condition. The overviews were screened by two authors independently, and the extraction was performed by one author and checked by a second. We found 353 overviews published between 2005 and 2022 that met the inclusion criteria. Results: One hundred and sixty-four overviews (46%) used at least one strategy to visualize, quantify, or resolve overlap, with a matrix (32/164; 20%), absolute frequency (34/164; 21%), and authors’ algorithms (24/164; 15%) being the most used methods, respectively. From 2016 onwards, there has been a trend toward increasing the use of some strategies to manage overlap. Of the 108 overviews that used some strategy to resolve the overlap, ie, avoiding double or multiple counting of primary study data, 79 (73%) succeeded. In overviews where no strategies to manage overlap were reported (n 5 189/353; 54%), 16 overview authors (8%) recognized this as a study limitation. Conclusion: Although there is a trend toward increasing its use, only half of the authors of the overviews of exercise-related interventions used a strategy to visualize, quantify, or resolve overlap in the primary studies’ data. In the future, authors should report such strategies to communicate more valid results.