Exercise dose-response relationship with heart rate variability in individuals with overweight and obesity: protocol for a systematic review and meta-analysis of randomised controlled trials.

INTRODUCTION: Obesity is a chronic relapsing disease process and serious public health concern that can lead to chronic diseases, medical complications and a higher risk of disability. Another significant feature of obesity is dysfunction in cardiac autonomic function, which leads to changes in parasympathetic and sympathetic regulation, which can be measured using heart rate variability (HRV). The objective of this review is to estimate the extent to which exercise doses impacts on HRV among individuals living with overweight and obesity class I and II. METHODS AND ANALYSIS: A systematic literature search will be performed using PubMed/Medline, Scopus, EMBASE, ProQuest, CINAHL, Web of Science and the Cochrane Library for articles dating from 1965 to December 2021. Inclusion criteria include studies designed as parallel-arm randomised trials, enrolling adolescent and adult individuals with overweight (body mass index, BMI≥25 to ≤29.9) and obesity (class I BMI: 30-34.9 and class II BMI: 35-39.9) undergoing aerobic or resistance training or concurrent exercise training. For data synthesis, sensitivity analysis, subgroup analysis and risk of bias assessment, Stata V.13.0 software will be used. ETHICS AND DISSEMINATION: Formal ethical approval is not required. This systematic review will be submitted to a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42019104154.

Reducing research wastage by starting off on the right foot: optimally framing the research question.

PURPOSE: Strongly framed research questions are clear as to the population (P), the exposures or interventions (E/I), comparison groups (C), outcomes (O), time when relevant (T), and what the investigator wants to know. A solid framework sets up the measurement model, analysis, and anticipated results. The purpose of this study was to estimate the extent to which research questions in journals that focused on patient-reported outcome measures (PROM) and quality of life (QOL) are clear. METHODS: All 440 research articles published in four PROM journals in 2020. excluding reviews, psychometric, and qualitative papers, were reviewed. Research questions were classified as: (i) adequately framed (ii) poorly framed; or (iii) unframed based on clarity criteria. Examples from each journal were presented and reframed to match results in the article. RESULTS: Of 440 articles, 195 (44.3%) were classified as adequately framed; 230 (52.2%) as poorly framed; and 15 (3.4%) as unframed. There was heterogeneity across journals (Chi-square: 20.8; 6 df; p = 0.002). Only 29% were framed according to what the investigators wanted to know; 72% were framed like a "to do" list; and 6% were framed as a research agenda. CONCLUSION: Almost half of the questions were poorly framed or unframed a practice that could contribute to research wastage. Even "adequately framed" questions rarely stated what they wanted to know a priori, increasing the risk of biased reporting. Researchers, reviewers, and editors should encourage the use established frameworks for research questions.

Bi-level Positive Airway Pressure (BiPAP) with standard exhalation valve does not improve maximum exercise capacity in patients with COPD.

BACKGROUND: Although BiPAP has been used as an adjunct to exercise, little is know about its effect on exercise in COPD. We aimed to evaluate the acute effect of BiPAP delivered with a standard valve (Vision, Respironics), compared to no assist, on exercise capacity in individuals with COPD. METHODS: Peak exercise workload (WLpeak), dyspnea (Borg), end-expiratory lung volume (EELV), tidal volume (VT), minute ventilation (VE), O2 uptake (VO2), and CO2 production (VCO2) were assessed in 10 COPD patients (FEV1 53 ± 22% pred) during three symptom-limited bicycle exercise tests while breathing i) without a ventilator (noPS), ii) with a pressure support (PS) of 0 cm H2O (PS0; IPAP & EPAP 4 cm H2O) and iii) PS of 10 cm H2O (PS10; IPAP 14 & EPAP 4 cm H2O) on separate days using a randomized crossover design. RESULTS: WLpeak was significantly lower with PS10 (33 ± 16) and PS0 (30.5 ± 13) than noPS (43 ± 19) (p < 0.001). Dyspnea at peak exercise was similar with noPS, PS0 and PS10; at isoload it was lower with noPS compared to PS10 and PS0 (p < 0.01). VT and VE were highest with PS10 and lowest with noPS both at peak exercise and isoload (p < 0.001). EELV was similar at peak exercise with all three conditions. VO2 and VCO2 were greater with PS10 and PS0 than noPS (p < 0.001), both at peak exercise and isoload. CONCLUSION: Use of BiPAP with a standard exhalation valve during exercise increases VT and VE at the expense of augmenting VCO2 and dyspnea, which in turns reduces WLpeak in COPD patients.