Effects of exercise on bone marrow adipose tissue in children with overweight/obesity: role of liver fat.

CONTEXT: Exercise reduces adiposity, but its influence on bone marrow fat fraction (BMFF) is unknown; nor is it known whether a reduction in liver fat content mediates this reduction. OBJECTIVES: (i) To determine whether incorporating exercise into a lifestyle program reduces the lumbar spine (LS)-BMFF, and (ii), to investigate whether changes in liver fat mediate any such effect. DESIGN: Ancillary analysis of a two-arm, parallel, non-randomized clinical trial. SETTING: Primary care centres in Vitoria-Gasteiz (Spain). PARTICIPANTS: A total of 116 children with overweight/obesity were assigned to a 22-week family-based lifestyle program (control group [n=57]) or the same program plus an exercise intervention (exercise group [n=59]. INTERVENTIONS: The compared interventions consisted of a family-based lifestyle program (two 90-minute sessions/month) and the same program plus supervised exercise (three 90-minute sessions/week). MAIN OUTCOMES AND MEASURES: The primary outcome examined was the change in LS-BMFF between baseline and 22 weeks, as estimated by MRI. The effect of changes in hepatic fat on LS-BMFF were also recorded. RESULTS: Mean weight loss difference between groups was 1.4±0.5 kg favour of the exercise group. Only the children in the exercise group experienced a reduction in LS-BMFF (effect size [Cohen d] -0.42, CI: -0.86, -0.01). Importantly, 40.9% of the reductions in LS-BMFF were mediated by changes in percentage hepatic fat (indirect effect: ß=-0.104, 95%CI=-0.213, -0.019). The impact of changes in hepatic fat on LS-BMFF was independent of weight loss. CONCLUSIONS AND RELEVANCE: The addition of exercise to a family-based lifestyle program designed to reduce cardiometabolic risk improves bone health by reducing LS-BMFF in children with overweight or obesity. This beneficial effect on bone marrow appears to be mediated by reductions in liver fat.

Impact of lifestyle moderate-to-vigorous physical activity timing on glycemic control in sedentary adults with overweight/obesity and metabolic impairments.

OBJECTIVE: Moderate-to-vigorous physical activity (MVPA) improves glucose levels; however, whether its timing affects daily glycemic control remains unclear. This study aims to investigate the impact of lifestyle MVPA timing on daily glycemic control in sedentary adults with overweight/obesity and metabolic impairments. METHODS: A total of 186 adults (50% women; age, 46.8 [SD 6.2] years) with overweight/obesity (BMI, 32.9 [SD 3.5] kg/m2) and at least one metabolic impairment participated in this cross-sectional study. MVPA and glucose patterns were simultaneously monitored over a 14-day period using a triaxial accelerometer worn on the nondominant wrist and a continuous glucose-monitoring device, respectively. Each day was classified as "inactive" if no MVPA was accumulated; as "morning," "afternoon," or "evening" if >50% of the MVPA minutes for that day were accumulated between 0600 and 1200, 1200 and 1800, or 1800 and 0000 hours, respectively; or as "mixed" if none of the defined time windows accounted for >50% of the MVPA for that day. RESULTS: Accumulating >50% of total MVPA during the evening was associated with lower 24-h (mean difference [95% CI], -1.26 mg/dL [95% CI: -2.2 to -0.4]), diurnal (-1.10 mg/dL [95% CI: -2.0 to -0.2]), and nocturnal mean glucose levels (-2.16 mg/dL [95% CI: -3.5 to -0.8]) compared with being inactive. This association was stronger in those participants with impaired glucose regulation. The pattern of these associations was similar in both men and women. CONCLUSIONS: These findings suggest that timing of lifestyle MVPA is significant. Specifically, accumulating more MVPA during the evening appears to have a beneficial effect on glucose homeostasis in sedentary adults with overweight/obesity and metabolic impairments.

Targeted proteomics involved in cardiovascular health and heart rate variability in children with overweight/obesity.

BACKGROUND: Children with overweight/obesity often exhibit alterations in their plasma protein profiles and reduced heart rate variability (HRV). Plasma proteomics is at the forefront of identifying biomarkers for various clinical conditions. We aimed to examine the association between plasma-targeted proteomics involved in cardiovascular health and resting vagal-related HRV parameters in children with overweight/obesity. METHODS: Forty-four children with overweight/obesity (10.2 ± 1.1 years old; 52% boys) participated in the study. Olink's technology was used to quantify 92 proteins involved in cardiovascular health. HRV was measured using a heart rate monitor (Polar RS800CX). Four resting vagal-related HRV parameters were derived in time- and frequency-domain. RESULTS: Eight proteins (KIM1, IgG Fc receptor II-b, IDUA, BOC, IL1RL2, TNFRSF11A, VSIG2, and TF) were associated with at least one out of the four vagal-related HRV parameters (ß values ranging from -0.188 to 0.288; all p < .05), while KIM1, IDUA, and BOC associated with ≥ three vagal-related HRV parameters. Multiple hypothesis testing corrections did not reach statistical significance (false discovery rate [FDR >0.05]). CONCLUSION: Plasma-targeted proteomics suggested novel biomarkers for resting vagal-related HRV parameters in children with overweight/obesity. Future studies using larger cohorts and longitudinal designs should confirm our findings and their potential clinical implications.

Impact of a short-term nitrate and citrulline co-supplementation on sport performance in elite rowers: a randomized, double-blind, placebo-controlled crossover trial.

PURPOSE: Citrulline (CIT) and beetroot extract (BR) have separately shown benefits in rowing performance-related outcomes. However, effects of combined supplementation remain to be elucidated. The main purpose of this research was to study the effects of 1 week of daily co-supplementation of 3.5 g BR (500 mg NO3-) plus 6 g CIT on aerobic performance, maximal strength, and high-intensity power and peak stroke in elite male rowers compared to a placebo and to a BR supplementation. METHODS: 20 elite rowers participated in this randomized, double-blind, placebo-controlled crossover trial completing 1 week of supplementation in each group of study: Placebo group (PLAG); BR group (BRG); and BR + CIT group (BR-CITG). 3 main physical tests were performed: aerobic performance, Wingate test and CMJ jump, and metabolic biomarkers and physiological outcomes were collected. RESULTS: The Wingate all-out test showed no between-condition differences in peak power, mean power, relative power, or fatigue index (P > 0.05), but clearance of lactate was better in BR-CITG (P < 0.05). In the performance test, peak power differed only between PLAG and BR-CITG (P = 0.036), while VO2peak and maximum heart rate remained similar. CMJ jumping test results showed no between-condition differences, and blood samples were consistent (P > 0.200). CONCLUSION: Supplementation with 3.5 g of BR extract plus 6 g of CIT for 7 days improved lactate clearance after Wingate test and peak power in a performance test. No further improvements were found, suggesting longer period of supplementation might be needed to show greater benefits.

Resting heart rate but not heart rate variability is associated with the normal-weight obesity phenotype.

OBJECTIVE: To determine differences in resting heart rate variability (HRV) and heart rate (HR) between young adults with normal-weight obesity (NWO) and normal-weight lean (NWL). METHODS: A total of 65 normal-weight individuals (18-25 years old, 50 women, body mass index 18.5 to 24.9 kg/m2) were included in this cross-sectional study. Body fat percentage was determined using a whole-body dual energy x-ray absorptiometry scanner. Resting HRV and HR were assessed with the Polar RS800CX. Forty-one participants were classified as NWO and 24 NWL using cutoff points for body fat percentage (33.3% for women and 23.1% for men). RESULTS: There were no differences in HRV between NWO and NWL groups (all p > .05). HR was higher in NWO (mean 70 beats per minute [bpm], standard deviation [SD] 8) than in NWL adults (mean 65 bpm, SD 10), the adjusted mean difference 5 bpm (95% CI, 0 to 10 bpm). CONCLUSION: HR is a noninvasive biomarker and relatively cheap, fast, and easy to measure that could detect "apparently healthy" young individuals with an adverse cardiovascular disease risk profile despite presenting a normal body weight.

Impact of Equation Choice on Resting Metabolic Rate Ratio in High-Level Men and Women Athletes.

OBJECTIVE: To examine the impact of the RMR ratio cutoff point selected on the categorization of prevalence/absence of low energy availability among predictive equations in high-level athletes (n = 241 [99 women]; 52% competed at the World Championship and Olympic Games), and whether this categorization is influenced by sex and the predictive equation used. METHODS: We assessed RMR using indirect calorimetry, predicted the RMR using the equations proposed by Harris-Benedict, FAO/WHO/UNU, de Lorenzo, ten Haaf and Wejis, Wong, Jagim, Cunningham, and Freire, and computed the RMR ratio for each equation. RESULTS: We observed that the cumulative percentage of RMR ratio values increased at a faster rate using Jagim, ten Haaf and Wejis, and Cunningham equations compared to the other equations. At the 0.90 value (the most used cutoff point in literature), the Jagim equation categorized ≥ 50% of the athletes into "low energy availability". No Sex × Equation × Sport interaction effect was observed (F = 0.10, p = 1.0). There was a significant main effect to Sex (F = 11.7, p < 0.001, ES = 0.05), Sport (F = 16.4, p < 0.001, ES = 0.01), and Equation (F = 64.1, p < 0.001, ES = 0.19). Wong and FAO/WHO/UNU equations yielded the largest errors (assessed vs. predicted RMR) in men and women, respectively. CONCLUSION: The selected RMR ratio cutoff point influences the prevalence/absence of low energy availability characterization in high-level athletes and suggests that certain equations could bias its assessment.

Adults with metabolically healthy overweight or obesity present more brown adipose tissue and higher thermogenesis than their metabolically unhealthy counterparts.

BACKGROUND: There is a subset of individuals with overweight/obesity characterized by a lower risk of cardiometabolic complications, the so-called metabolically healthy overweight/obesity (MHOO) phenotype. Despite the relatively higher levels of subcutaneous adipose tissue and lower visceral adipose tissue observed in individuals with MHOO than individuals with metabolically unhealthy overweight/obesity (MUOO), little is known about the differences in brown adipose tissue (BAT). METHODS: This study included 53 young adults (28 women) with a body mass index (BMI) ≥25 kg/m2 which were classified as MHOO (n = 34) or MUOO (n = 19). BAT was assessed through a static 18F-FDG positron emission tomography/computed tomography scan after a 2-h personalized cooling protocol. Energy expenditure, skin temperature, and thermal perception were assessed during a standardized mixed meal test (3.5 h) and a 1-h personalized cold exposure. Body composition was assessed by dual-energy x-ray absorptiometry, energy intake was determined during an ad libitum meal test and dietary recalls, and physical activity levels were determined by a wrist-worn accelerometer. FINDINGS: Participants with MHOO presented higher BAT volume (+124%, P = 0.008), SUVmean (+63%, P = 0.001), and SUVpeak (+133%, P = 0.003) than MUOO, despite having similar BAT mean radiodensity (P = 0.354). In addition, individuals with MHOO exhibited marginally higher meal-induced thermogenesis (P = 0.096) and cold-induced thermogenesis (+158%, P = 0.050). Moreover, MHOO participants showed higher supraclavicular skin temperature than MUOO during the first hour of the postprandial period and during the cold exposure, while no statistically significant differences were observed in other skin temperature parameters. We observed no statistically significant differences between MHOO and MUOO in thermal perception, body composition, outdoor ambient temperature exposure, resting metabolic rate, energy intake, or physical activity levels. INTERPRETATION: Adults with MHOO present higher BAT volume and activity than MUOO. The higher meal- and cold-induced thermogenesis and cold-induced supraclavicular skin temperature are compatible with a higher BAT activity. Overall, these results suggest that BAT presence and activity might be linked to a healthier phenotype in young adults with overweight or obesity. FUNDING: See acknowledgments section.

Sex-specific dose-response effects of a 24-week supervised concurrent exercise intervention on cardiorespiratory fitness and muscular strength in young adults: The ACTIBATE randomized controlled trial.

Concurrent training has been postulated as an appropriate time-efficient strategy to improve physical fitness, yet whether the exercise-induced adaptations are similar in men and women is unknown. An unblinded randomized controlled trial was conducted to investigate sex-specific dose-response effects of a 24-week supervised concurrent exercise training program on cardiorespiratory fitness and muscular strength in young adults. One hundred and forty-four sedentary adults aged 18-25 years were assigned to either (i) a control group (n = 54), (ii) a moderate intensity exercise group (MOD-EX, n = 46), or (iii) a vigorous intensity exercise group (VIG-EX, n = 44) by unrestricted randomization. Cardiorespiratory fitness (VO2max ), hand grip strength, and one-repetition maximum of leg press and bench press were evaluated at baseline and after the intervention. A total of 102 participants finished the intervention (Control, n = 36; 52% women, MOD-EX, n = 37; 70% women, and VIG-EX, n = 36; 72% women). In men, VO2max significantly increased in the MOD-EX (~8%) compared with the control group and in the VIG-EX group after the intervention (~6.5%). In women, VO2max increased in the MOD-EX and VIG-EX groups (~5.5%) compared with the control group after the intervention. There was a significant increment of leg press in the MOD-EX (~15.5%) and VIG-EX (~18%) groups compared with the control group (~1%) in women. A 24-week supervised concurrent exercise was effective at improving cardiorespiratory fitness and lower body limbs muscular strength in young women-independently of the predetermined intensity-while only at moderate intensity improved cardiorespiratory fitness in men.

Intra-Assessment Resting Metabolic Rate Variability Is Associated with Cardiometabolic Risk Factors in Middle-Aged Adults.

The intra-assessment resting metabolic rate variability is related to cardiometabolic health, as suggested by previous literature. We studied whether that variability (expressed as coefficient of variation [CV; %]) for oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory exchange ratio (RER), and resting energy expenditure (REE) is similar between men and women, and if is similarly associated with cardiometabolic risk factors. Gas exchange in 72 middle-aged adults was measured by indirect calorimetry. Anthropometrics and body composition, cardiorespiratory fitness, circulating cardiometabolic risk factors, and heart rhythm parameters were also determined. Men and women presented similar intra-assessment resting metabolic rate variability (all p > 0.05). Notably, in men, CV for RER was positively associated with BMI and adiposity (both standardized ß = 0.35, Ps ≤ 0.048), while CVs for VO2, VCO2, and REE were negatively associated (standardized ß ranged from -0.37 to -0.46, all p ≤ 0.036) with cardiometabolic risk factors. In women, CVs for VCO2 and REE were negatively associated with adiposity (both standardized ß = -0.36, Ps ≤ 0.041) and cardiometabolic risk Z-score (standardized ß = -0.40 and -0.38, respectively, Ps ≤ 0.05). In conclusion, intra-assessment resting metabolic rate variability could be considered an indicator of cardiometabolic health in middle-aged adults.

Neutralizing Antibodies against SARS-CoV-2: Importance of Comorbidities in Health Personnel against Reinfections.

One of the priority lines of action to contain the SARS-CoV-2 pandemic was vaccination programs for healthcare workers. However, with the emergence of highly contagious strains, such as the Omicron variant, it was necessary to know the serological status of health personnel to make decisions for the application of reinforcements. The aim of this work was to determine the seroprevalence against SARS-CoV-2 in healthcare workers in a Mexican hospital after six months of the administration of the Pfizer-BioNTech vaccine (two doses, 4 weeks apart) and to investigate the association between comorbidities, response to the vaccine, and reinfections. Neutralizing antibodies against SARS-CoV-2 were determined using ELISA assays for 262 employees of Hospital Juárez de México with and without a history of COVID-19. A beta regression analysis was performed to study the associated comorbidities and their relationship with the levels of antibodies against SARS-CoV-2. Finally, an epidemiological follow-up was carried out to detect reinfections in this population. A significant difference in SARS-CoV-2 seroprevalence was observed in workers with a history of COVID-19 prior to vaccination compared to those without a history of the disease (MD: 0.961 and SD: 0.049; <0.001). Beta regression showed that workers with a history of COVID-19 have greater protection compared to those without a history of the infection. Neutralizing antibodies were found to be decreased in alcoholic and diabetic subjects (80.1%). Notably, eight cases of Omicron reinfections were identified, and gender and obesity were associated with the presence of reinfections (6.41 OR; 95% BCa CI: 1.15, 105.0). The response to the vaccine was influenced by the history of SARS-CoV-2 infection and associated comorbidities. The above highlights the importance of prioritizing this segment of the population for reinforcements in periods of less than one year to guarantee their effectiveness against new variants.

Brachybacterium conglomeratum Is Associated with Cervicovaginal Infections and Human Papilloma Virus in Cervical Disease of Mexican Female Patients.

Brachybacterium conglomeratum, traditionally considered an environmental bacterium, has recently garnered attention for its potential involvement in human health. While prior research hinted at its pathogenic role in humans, our study aims to determine its prevalence and associations in diverse clinical contexts. We examined vaginal swabs from three distinct patient groups: patients with low-grade squamous intraepithelial lesions (LSIL), patients with cervicovaginal infections, and patients with a history of precancerous lesions undergoing follow-up. B. conglomeratum was present in all three patient groups, with the highest prevalence observed in the LSIL group. Statistically significant associations were primarily identified in the LSIL group, where B. conglomeratum was present in 60% of cases. Notably, the LSIL group exhibited coinfections with multiple high-risk oncogenotypes of human papillomavirus (HPV), suggesting potential synergistic effects, and understanding these microbial relationships and their influence on viral persistence, particularly with HPV, holds promise for mitigating HPV-related carcinogenesis. Furthermore, Gardnerella vaginalis and Atopobium vaginae were frequently detected in this group, along with Ureaplasma parvum as the predominant sexually transmitted bacterium. In all cases, B. conglomeratum was found in association with these microorganisms rather than as a sole pathogen. This coexistence underscores the intricate microbial interactions within cervicovaginal infections and precancerous lesions. This study marks the first report of B. conglomeratum prevalence in women with these clinical conditions.

Rapid Rescoring and Refinement of Ligand-Receptor Complexes Using Replica Exchange Molecular Dynamics with a Monte Carlo Pose Reservoir.

Virtual screening (VS) involves generation of poses for a library of ligands and ranking using simplified energy functions and limited flexibility. Top-scored poses are used to rank and prioritize ligands. Here, we adapt the reservoir replica exchange molecular dynamics (res-REMD) method to rerank poses generated through VS. REMD simulations are carried out but with occasional Monte Carlo jumps to alternate VS-generated poses using a Metropolis criterion. The simulations converge within 10 ns for all systems, generating populations of alternate poses in the context of fully flexible ligand and protein side chains. The protocol is applied to four model protein-ligand complexes, where DOCK resulted in two successes and two scoring failures. In all four systems, the most populated cluster from the final ensemble exhibits high similarity to the crystallographic pose with ligand RMSD values under 2.0 Å. Both DOCK failures were rescued. For one DOCK success, the protocol identified the correct pose but also sampled an alternate pose at equal probability. Opportunities for future improvements and extensions are discussed.

Factores sociodemográficos y socioculturales que influyen en la donación de sangre en el Perú: resultados de una encuesta nacional, 2022 / Sociodemographic and sociocultural factors that influence blood donation in Perú: results of a national survey, 2022

RESUMEN Introducción: Los factores sociodemográficos y socioculturales influyen en la donación de sangre en diversos países, nuestro objetivo de estudio fue determinar cuáles son los factores que influyen en la donación de sangre en el Perú. El estudio: Se realizó un estudio observacional, transversal en personas entre 18 a 60 años a nivel nacional, se analizaron los datos mediante SPSS v.20 Hallazgos: La muestra de estudio fue de 739 personas, el 50,4% hombres; se determinó que hay buen conocimiento acerca de la donación de sangre con un porcentaje mayor al 50% de preguntas contestadas correctamente, así mismo existe una actitud positiva frente a la donación de sangre Conclusiones: Los factores socioculturales que influyen en la donación de sangre es el desconocimiento, un 40% de los participantes desconoce los requisitos básicos para ser donante de sangre, otro factor es la falsa creencia que al estar tomando medicamentos no se puede donar sangre (47%).

ABSTRACT Background: Sociodemographic and sociocultural factors influence blood donation in various countries, our objective of study was to determine what are the factors that influence blood donation in Peru. The study: An observational, crosssectional study was conducted in people between 18 and 60 years at the national level, the data were analyzed using SPSS v.20 Findings: The study sample was 739 people, 50.4% men; It was determined that there is good knowledge about blood donation with a percentage greater than 50% of questions answered correctly, likewise there is a positive attitude towards blood donation Conclusions: The sociocultural factors that influence blood donation is ignorance, 40% of the participants do not know the basic requirements to be a blood donor, another factor is the false belief. because they are taking medication, they cannot donate blood (47%).

Effect of gas exchange data selection methods on resting metabolic rate estimation in young athletes.

This cross-sectional study analysed the effect of the gas exchange data selection methods on the resting metabolic rate (RMR) estimation and proposed a protocol shortening providing a suitable RMR estimation for young athletes. Sixty-six healthy young Brazilian athletes performed a 30-minute RMR assessment. Different methods of gas exchange data selection were applied: short and long-time intervals, steady-state (SSt), and filtering. A mixed one-way ANOVA was used to analyse the mean differences in gas exchange, RMR, respiratory exchange ratio (RER), and coefficients of variation across all methods. Additionally, paired Student's t-test were used to compare the first and best SSt RMR values for each SSt method (3, 4, and 5-min). The 5-min SSt method provided the lowest RMR estimate (1454 kcal.day-1). There was a statistical difference between methods (F = 2.607, p = 0.04), but they presented a clinically irrelevant absolute difference (~36 kcal.day-1). There were no differences in RER among methods. In addition, using the SSt method, 12 minutes of assessment were enough to obtain a valid estimation of RMR. The 5-min SSt method should be employed for assessing the RMR among young athletes, considering the possibility of obtaining a shortened assessment (~12 min) with an acceptable and low coefficient of variation.

Effect of Moderate Versus Vigorous Exercise Intensity on Body Composition in Young Untrained Adults: The Activating Brown Adipose Tissue Through Exercise (ACTIBATE) Randomized Controlled Trial.

The present study aimed to investigate the effect of a 24-week aerobic + resistance training programs at moderate versus vigorous intensity on body composition, and the persistence of the changes after a 10-month free-living period, in young untrained adults. This report is based on a secondary analysis from the activating brown adipose tissue through exercise (ACTIBATE) single-center unblinded randomized controlled trial. A total of 144 young adults (65.6% women) aged 18-25 years were randomly allocated to three different groups: (a) aerobic + resistance exercise training program based on the international physical activity recommendations at vigorous intensity (Ex-Vigorous group), (b) at moderate intensity (Ex-Moderate group), and (c) control group (no exercise). Body composition outcomes were determined by a dual-energy X-ray absorptiometry scanner. Both Ex-Vigorous and Ex-Moderate decreased body weight, fat mass, and visceral adipose tissue mass in a similar manner (all p < .04). After a 10-month free-living period, these parameters returned to baseline levels in both exercise groups (all ps < .03). No differences between the exercise groups and the control group were noted in lean mass changes (all ps > .1). A 24-week aerobic + resistance training intervention based on the international physical activity recommendations was enough to improve body weight, fat mass, and visceral adipose tissue mass in untrained young adults, independently of the exercise intensity (moderate vs. vigorous).

Resting Metabolic Rate of Individuals.

The resting metabolic rate (RMR) represents the energy required to sustain normal body functions and homeostasis in an awake individual under ambient thermoneutral conditions and during rest [...].

Medical imaging in the assessment of cardiovascular disease risk.

PURPOSE OF REVIEW: The prevalence of obesity has exponentially increased during the past years. The assessment of human adipose tissue distribution enables the identification of diverse ectopic adipose tissue depots, and helps to explain its relationship with cardiovascular health status. In this review, we summarize the current methods used in the assessment of human adipose tissue distribution, and we discuss the relationship between ectopic adipose tissue distribution and the risk of developing cardiovascular diseases and metabolic complications. RECENT FINDINGS: The reference instruments to assess human adipose tissue distribution nowadays are the computed tomography and the magnetic resonance imaging (MRI). Today, MRI is the preferred imaging technique and enables the measurement of variations in the distribution of body adipose tissue among different phenotypes and individuals. This technique has helped to better understand the relationship between different ectopic adipose tissue depots and its relationship with cardiometabolic health among individuals. SUMMARY: Although body composition can be assessed by simple techniques, these calculations can provide erroneous results and conclusions, requiring complex interpretations when diverse metabolic situations are concomitantly engaged. Contrarily, medical imaging techniques (e.g. MRI) enables to objectively and unbiasedly measure changes that may occur during longitudinal studies (e.g. pharmacological drug interventions).

Heart Rate Variability and Cardiorespiratory Fitness in Youth Populations: The Impact of Heart Rate on Data Analysis.

The positive association between heart rate variability and cardiorespiratory fitness in youth populations is unclear. In this regard, several methodological aspects related to heart rate variability analysis could partially explain the disagreement between studies. To the best of the authors' knowledge, the influence of the heart rate on data analysis is unclear. In the present short communication, we discuss the impact of the heart rate on the associations between heart rate variability and cardiorespiratory fitness in youth. In addition, we proposed some aspects that should be considered for statistical analyses when the relationship between heart rate variability and cardiorespiratory fitness is studied. Finally, we should acknowledge that these recommendations may be applicable for other health-related outcomes different than cardiorespiratory fitness (e.g., inflammatory markers, cognition, cardiovascular disease status).

Detraining Effect on Cardiac Autonomic Response to an All-Out Sprint Exercise in Trained Adolescent Swimmers.

PURPOSE: This study aimed to investigate the effects of a 5-week training cessation on the cardiac autonomic response after a 50-m swimming time-trial test. METHODS: Twenty trained and highly trained adolescent swimmers (17.1 [2.7] y) performed a 50-m front-crawl all-out test before (visit 1) and after a 5-week training cessation (visit 2). After the warm-up, heart-rate variability (HRV) was recorded in a seated position using a Polar RS800CX heart-rate monitor during the 10 minutes before (preexercise) and immediately after the 50-m front-crawl all-out test (postexercise). Two-way analysis of variance (time × visit) and analysis of covariance were conducted to compute the effect of the 50-m all-out test on vagal-related HRV parameters (mean R-R, standard deviation of R-R intervals [SDNN], square root of the mean squared differences between successive R-R intervals [RMSSD], the percentage number of pairs of adjacent normal R-R intervals differing by more than 50 milliseconds in the entire recording [pNN50], and power in the high frequency [HF]) with Bonferroni post hoc test. RESULTS: All the HRV parameters had a time main effect (P < .05), showing a reduction after the 50 m in both visits (P < .05). All the variables exhibited a visit main effect (P < .05); the preexercise and postexercise mean R-R, natural logarithm SDNN, natural logarithm RMSSD, and natural logarithm HF values declined after the training cessation (P < .05). Natural logarithm pNN50 preexercise values were reduced in visit 2 compared with visit 1 (P < .05). Only mean R-R was further reduced in response to the test in visit 2 compared with visit 1 (P < .05). CONCLUSIONS: After 5 weeks of training cessation, all the preexercise and postexercise vagal-related HRV parameters evidenced a reduction, suggesting an impairment in swimmers' physical status. Coaches should be cautious with training loads at the start of the season.

"Appagalo" a Customized Mobile Health Intervention (mHealth) for Smoking Cessation in Women: A Randomized Controlled Trial.

BACKGROUND: Almost 30% of Chilean women report cigarette smoking with important repercussions on their health. OBJECTIVE: Design and test a mobile phone intervention for smoking cessation in young women. STUDY DESIGN: A mobile application (app) was created using the best available evidence and consumer input. Its effectiveness was assessed through a randomized clinical trial. STUDY PARTICIPANTS: Women 18 to 44 years old from middle-class neighborhoods in Santiago, Chile. Inclusion criteria were intention to quit cigarette smoking in the following month and having a smartphone cell phone. Women with positive screening for risky alcohol consumption were excluded. INTERVENTION: App with content to support cigarette smoking cessation over 6 months. The control arm included an app that delivered general messages to promote permanence in the study. Telephone follow-up was performed at 6 weeks, and at 3 and 6 months after randomization. MAIN OUTCOME MEASURE: No smoking in the past 7 days at 6 weeks from enrolment. Intention-to-treat analysis was carried out using SPSS 17.0 with a significance level set at .05. RESULTS: 309 women entered the study. Mean number of cigarettes smoked in a day was 8.8. 58.6% of the participants (n = 181) completed the follow-up for the primary outcome. With intention-to-treat analysis, 9.7% of participants in the intervention group reported not having smoked any cigarettes in the last 7 days vs 3.2% in the control group (RR 2.98 CI 95% 1.11-8.0, P = .022). Additionally, 12.3% vs 1.9% of the participants in the intervention group and control group reported continuous abstinence at 6 weeks, respectively (RR 6.29 95% CI 1.9-20.8, P < .001). Continuous abstinence was also significant at 6 months (P-value of .036). CONCLUSIONS: The "Appagalo" app is an effective tool to support smoking cessation in young women. It is a simple mHealth alternative for smoking cessation that can contribute to improving women's health in the Americas and worldwide.