Influence of physical fitness and weight status on autonomic cardiac modulation in children.

BACKGROUND: This study provides reference values for cardiovascular modulation at rest, during maximal exercise test and recovery after exercise in Caucasian children according to weight status and cardiorespiratory fitness (CRF) level. Additionally, the current study analyzed several correlations between autonomic cardiovascular modulation, cardiorespiratory performance and cardiometabolic risk. The principal goal of this study was to analyze cardiac function at rest, during maximum exercise, and during the recovery phase in children grouped according to weight status and CRF level. METHODS: One hundred and fifty-two healthy children (78 girls) 10-16 years of age were divided into three groups: soccer and basketball players (SBG), endurance group (EG), and sedentary people with overweight and obesity (OOG). A cardiac RR interval monitor recorded the cardiac data and specific software analyzed the cardiac autonomic response through heart rate (HR) and HR variability. The study analyzed resting HR (RHR), HRpeak, and HR recovery (HRR). RESULTS: OOG showed significant poorer performance in the Léger test lower V̇O2 max and higher values of blood pressure at rest and post-exercise than sport groups. The EG presented the best results in CRF and cardiometabolic risk (CMR) in relation to SBG and OOG. The OOG showed higher percentage of HR values, compatible with an unhealthy cardiovascular autonomic modulation than the sport groups, with significant differences in bradycardia, HR reserve, and HRR 5 min. CONCLUSIONS: Aerobic performance, vagal activity, blood pressure, chronotropic competence, and HRR have significant associations with CMR parameters. IMPACT: The current study presents reference values of autonomic cardiac function in Caucasian children according to weight status and cardiorespiratory fitness level. Aerobic performance, vagal activity, blood pressure, chronotropic competence, and heart rate during the recovery period after exercise have significant associations with cardiometabolic risk parameters. Children with overweight and obesity show signs of autonomic dysfunction reflected as low cardiac vagal activity and poor chronotropic competence.

Utilizing Age-Predicted Heart Rate Maximum to Prescribe a Minimally Invasive Cycle Ergometer HIIT Protocol in Older Adults: A Feasibility Study.

Previous research has provided evidence that aerobic HIIT exercise can induce important physiological adaptations and elicit improvements in health and fitness parameters. However, most of the research has taken place in a laboratory setting with specialized equipment and monitoring devices. It begs the question, is HIIT accessible to the general aging population? The objective of the current research was to employ an age-predicted HRmax to prescribe a minimally invasive 4x4 cycle ergometer HIIT protocol. Ten participants (age: 64.2 ± 6.1) completed a non-weight-bearing cycle ergometer protocol for 6 weeks. Significant Pearson correlations were found between %HRmax and W/kg in seven of the ten participants. Two participants showed significant correlations between RPE and W/kg. Half of the participants exhibited a significant correlation between %HRmax and RPE. Pre- to post-intervention measures demonstrated a significant increase in lower limb strength by the 10-repetition chair sit-to-stand (p = 0.004) and 30-second sit-to-stand (p = 0.021). Increased functional capacity demonstrated by TUG (p = 0.001) and SB (p = 0.034) also presented significant differences pre- to post-intervention. There was a 96% participant session completion rate. These data imply that a simple 4x4 cycle ergometer HIIT protocol prescribed using a %HRmax is effective at increasing lower-limb power/strength and can be used in the general older adult population without excessive oversight. Our intervention protocol demonstrates that 6 weeks of cycle ergometer HIIT is an adequate amount of time to result in lower limb strength and functional capacity improvements in active older adults.

Is the Xiaomi Mi Band 4 an Accuracy Tool for Measuring Health-Related Parameters in Adults and Older People? An Original Validation Study.

BACKGROUND: The aim of this study was to analyse the validity and accuracy of the low-cost Xiaomi Mi Band 4 (MB4) fitness tracker in relation to step count and heart rate in free-living conditions. METHODS: 46 participants join in this study (38.65 ± 14.36 years old). The MB4 was compared with a video recording in laboratory conditions, also with the Sense Wear and Firstbeat monitors in free-living conditions. RESULTS: No significant differences were found in the number of steps in the laboratory protocol between devices, in both, at low and high walking speed. For the free-living conditions, the MB4 showed high values of convergent validity in relation to the Firstbeat monitor during recording in both rest and walking situations. Moreover, the MB4 showed adequate values of convergent validity with the Sense Wear monitor during the 24 h recording, at medium speeds, and climbing stairs. CONCLUSION: The accuracy and precision of the MB4 is reasonable and can be used to monitor the average of step count and heart rate in free-living conditions.

Healthy lifestyles and physical fitness are associated with abdominal obesity among Latin-American and Spanish preschool children: A cross-cultural study.

BACKGROUND: Identifying environmental factors that influence health in children are necessary to develop preventive strategies. OBJECTIVE: To determine the association between the lifestyles of children (i.e., Mediterranean diet (MD), physical activity (PA), fitness and screen time (ST) with abdominal obesity (AO) of preschoolers from three Spanish-speaking countries (Chile, Colombia and Spain) with different socioeconomic levels and Human Development Index (HDI) indicators. MATERIAL AND METHODS: This cross-sectional study included 982 schoolchildren (aged 4-6 years; 56.8% girls) from Chile (n = 409), Colombia (n = 281), and Spain (n = 292). Body mass index (BMI), waist circumference (WC), waist-to-height ratio (WtHR), adherence to the MD, PA, ST and physical fitness were evaluated. RESULTS: Spanish preschoolers reported a lower WtHR (p < 0.001), greater physical fitness (Z-score) (p < 0.001) and higher adherence to the MD (p < 0.001) than their Chilean and Colombian peers. In addition, Colombian preschoolers had a better lifestyle (PA + ST) than their Chilean and Spanish peers (p < 0.001). Chilean preschoolers reported a higher prevalence of AO than the Spanish preschoolers (65% vs. 51.9%; p = 0.001). CONCLUSION: Lifestyle had a significant association with AO among Spanish-speaking preschool children, with physical fitness especially being a relevant factor regardless of the country of origin. The findings of the current study may support the development of public guidelines focusing on healthy lifestyles in children to create effective plans that contribute to the early treatment of AO in preschool children.

Effect of COVID-19 confinement on physical activity patterns in relation to sociodemographic parameters in Spanish population.

BACKGROUND: The main purpose of the present study was to determine the sociodemographic parameters associated to physical activity (PA) patterns changes during the COVID-19 lockdown in the Spanish population. METHODS: Participants were recruited by sending a survey through various social network channels via the snowball method. A voluntary sample of 2430 individuals consisting of 1203 men and 1227 women (aged between 18 to 73 years old) from the Spanish national territory participated in this study. An online survey was performed to collect the information, which was tested through ad hoc analysis with different sociodemographic variables. Participants were a median of 34 years old (18-73 years old) with a mean BMI of 23.6 kg/m2. RESULTS: The risk factors associated with the change in PA hours during confinement showed that to do sports (ß=-56.88, 95% CI: -79.35 to -34.40, P<0.001), male sex (ß -34.78, 95%CI;-54.02 to -15.52, P<0.001) and the educational level (i.e., elementary school category) (ß=-54.21, 95%CI;-89.10 to -19.32, P=0.002) reported negative changes with hours of PA during confinement. By the contrary, the employment status (passive work) and to be student reported positive association (i.e., increase PA hours per week). CONCLUSIONS: The COVID-19 lockdown led to a reduction PA patterns in Spanish population. Mostly men showed a drastic decrease in hours of PA compared to the women's group. Likewise, the groups of people with elementary and high education showed a decrease in hours of weekly PA, as well as unemployed people.