Background: A better understanding of the effects of the lockdown on lifestyle behaviors may help to guide the public health response to COVID-19 at a national level and to update the global strategy to respond COVID-19 pandemic. The aim of the study was to examine the effects of the COVID-19 lockdown on device-measured physical activity (PA), sedentary time, sleep and self-regulation; and to determine whether PA and sleep are related to self-regulation problems during the lockdown. Methods: PA, sedentary time and sleep were assessed using accelerometry in the week in which the Spanish national state of alarm was declared (n = 21). Parents reported preschooler’s self-regulation difficulties (internalizing and externalizing) before (n = 268) and during the lockdown (n = 157) by a validated questionnaire. Results: Preschoolers showed a decrease in total PA (mean difference [MD] = −43.3 min per day, 95% CI −68.1 to −18.5), sleep efficiency (MD = −2.09%, 95% CI −4.12 to −0.05), an increase in sedentary time (MD = 50.2 min per day, 95% CI 17.1 to 83.3) internalizing (MD = 0.17, 95% CI 0.06 to 0.28) and externalizing (MD = 0.33, 95% CI 0.23 to 0.44) problems. Preschoolers who met the World Health Organization recommendations for PA had lower internalizing scores than non-active peers (MD = −1.28, 95% CI −2.53 to −0.03). Conclusions: Our findings highlight the importance of meeting PA recommendations to reduce psychosocial difficulties during a lockdown situation.

In a randomised controlled trial design, effects of 6 weeks of plyometric training on maximal-intensity exercise and endurance performance were compared in male and female soccer players. Young (age 21.1 ± 2.7 years) players with similar training load and competitive background were assigned to training (women, n = 19; men, n = 21) and control (women, n = 19; men, n = 21) groups. Players were evaluated for lower- and upper-body maximal-intensity exercise, 30 m sprint, change of direction speed and endurance performance before and after 6 weeks of training. After intervention, the control groups did not change, whereas both training groups improved jumps (effect size (ES) = 0.35-1.76), throwing (ES = 0.62-0.78), sprint (ES = 0.86-1.44), change of direction speed (ES = 0.46-0.85) and endurance performance (ES = 0.42-0.62). There were no differences in performance improvements between the plyometric training groups. Both plyometric groups improved more in all performance tests than the controls. The results suggest that adaptations to plyometric training do not differ between men and women.

IMPORTANCE Although the associations between cardiorespiratory fitness (CRF) and health in adults are well understood, to date, no systematic review has quantitatively examined the association between CRF during youth and health parameters later in life.OBJECTIVES To examine the prospective association between CRF in childhood and adolescence and future health status and to assess whether changes in CRF are associated with future health status at least 1 year later.DATA SOURCES For this systematic review and meta-analysis, MEDLINE, Embase, and SPORTDiscus electronic databases were searched for relevant articles published from database inception to January 30, 2020. STUDY SELECTIONThe following inclusion criteria were used: CRF measured using a validated test and assessed at baseline and/or its change from baseline to the end of follow-up, healthy population with a mean age of 3 to 18 years at baseline, and prospective cohort design with a follow-up period of at least 1 year.DATA EXTRACTION AND SYNTHESIS Data were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Random-effects models were used to estimate the pooled effect size. MAIN OUTCOMES AND MEASURES Anthropometric and adiposity measurements and cardiometabolic health parameters.RESULTS Fifty-five studies were included with a total of 37 563 youths (46% female). Weak-moderate associations were found between CRF at baseline and body mass index (r = -0.11; 95% CI, -0.18 to -0.04; I 2 = 59.03), waist circumference (r = -0.29; 95% CI, -0.42 to -0.14; I 2 = 69.42), skinfold thickness (r = -0.34; 95% CI, -0.41 to -0.26; I 2 = 83.87), obesity (r = -0.15; 95% CI, -0.23 to -0.06; I 2 = 86.75), total cholesterol level (r = -0.12; 95% CI, -0.19 to -0.05; I 2 = 75.81), high-density lipoprotein cholesterol (HDL-C) level (r = 0.11; 95% CI, 0.05-0.18; I 2 = 69.06), total cholesterol to HDL-C ratio (r = -0.19; 95% CI, -0.26 to -0.13; I 2 = 67.07), triglyceride levels (r = -0.10; 95% CI, -0.18 to -0.02; I 2 = 73.43), homeostasis model assessment for insulin resistance (r = -0.12; 95% CI, -0.18 to -0.06; I 2 = 68.26), fasting insulin level (r = -0.07; 95% CI, -0.11 to -0.03; I 2 = 0), and cardiometabolic risk (r = -0.18; 95% CI, -0.29 to -0.07; I 2 = 90.61) at follow-up. Meta-regression analyses found that early associations in waist circumference (β = 0.014; 95% CI, 0.002-0.026), skinfold thickness (β = 0.006; 95% CI, 0.002-0.011), HDL-C level (β = −0.006; 95% CI, −0.011 to −0.001), triglyceride levels (β = 0.009; 95% CI, 0.004-0.014), and cardiometabolic risk (β = 0.007; 95% CI, 0.003-0.011) from baseline to follow-up dissipated over time. Weak-moderate associations were found between change in CRF and body mass index (r = -0.17; 95% CI, -0.24 to -0.11; I 2 = 39.65), skinfold thickness (r = -0.36; 95% CI, -0.58 to -0.09; I 2 = 96.84), obesity (r = -0.21; 95% CI, -0.35 to -0.06; I 2 = 91.08), HDL-C level (r = 0.05; 95% CI, 0.02-0.08; I 2 = 0), low-density lipoprotein cholesterol level (r = -0.06; 95% CI, -0.11 to -0.01; I...

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IMPORTANCE Whether quality-or quantity-based physical education (PE) interventions are associated with improvement of health-related physical fitness outcomes and fundamental motor skills (FMSs) in children and adolescents is unknown. OBJECTIVE To examine the association of interventions aimed at optimizing PE in terms of quality (teaching strategies or fitness infusion) or quantity (lessons per week) with health-related physical fitness and FMSs in children and adolescents. DATA SOURCES For this systematic review and meta-analysis, studies were identified through a systematic search of Ovid MEDLINE, Embase, Cochrane Controlled Trials Registry, and SPORTDiscus databases (from inception to October 10, 2019) with the keywords physical education OR PE OR P.E. AND fitness AND motor ability OR skills. Manual examination of references in selected articles was also performed. STUDY SELECTION Studies that assessed the association of quality-or quantity-based PE interventions with improvement in physical fitness and/or FMSs in youths (aged 3-18 years) were included. DATA EXTRACTION AND SYNTHESIS Data were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Random-effects models were used to estimate the pooled effect size (Hedges g). MAIN OUTCOMES AND MEASURES Health-related physical fitness outcomes and FMSs. RESULTS Fifty-six trials composed of 48 185 youths (48% girls) were included in the meta-analysis. Quality-based PE interventions were associated with small increases in health-related physical fitness (cardiorespiratory fitness [Hedges g = 0.24; 95% CI, 0.16-0.32] and muscular strength [Hedges g = 0.19; 95% CI, 0.09-0.29]) and FMSs (Hedges g = 0.38; 95% CI, 0.27-0.49). Subgroup analyses found stronger associations for quality-based PE interventions on body mass index (Hedges g = −0.18; 95% CI, −0.26 to −0.09), body fat (Hedges g = −0.28; 95% CI, −0.37 to −0.18), cardiorespiratory fitness (Hedges g = 0.31; 95% CI, 0.23-0.39), and muscular strength (Hedges g = 0.29; 95% CI, 0.18-0.39). Quantity-based PE interventions were associated with small increases in only cardiorespiratory fitness (Hedges g = 0.42; 95% CI, 0.30-0.55), muscular strength (Hedges g = 0.20; 95% CI, 0.08-0.31), and speed agility (Hedges g = 0.29; 95% CI, 0.07-0.51). CONCLUSIONS AND RELEVANCEThe findings suggest that quality-based PE interventions are associated with small increases in both student health-related physical fitness components and FMSs regardless of frequency or duration of PE lessons. Because PE aims to improve more than health, high levels of active learning time may need to be balanced with opportunities for instruction, feedback, and reflection.

BackgroundThere is a lack of instruments and studies written in Spanish evaluating physical fitness, impeding the determination of the current status of this important health indicator in the Latin population, especially in Colombia. The aim of the study was two-fold: to examine the validity of the International Fitness Scale (IFIS) with a population-based sample of schoolchildren from Bogota, Colombia and to examine the reliability of the IFIS with children and adolescents from Engativa, Colombia.MethodsThe sample comprised 1,873 Colombian youths (54.5% girls) aged 9–17.9 years. We measured their adiposity markers (waist-to-height ratio, skinfold thickness, percentage of body fat and body mass index), blood pressure, lipids profile, fasting glucose, and physical fitness level (self-reported and measured). A validated cardiometabolic risk index score was also used. An age- and sex-matched subsample of 229 schoolchildren who were not originally included in the sample completed the IFIS twice for reliability purposes.ResultsOur data suggest that both measured and self-reported overall physical fitness levels were inversely associated with percentage of body fat indicators and the cardiometabolic risk index score. Overall, schoolchildren who self-reported “good” or “very good” fitness had better measured fitness levels than those who reported “very poor/poor” fitness (all p < 0.001). The test-retest reliability of the IFIS items was also good, with an average weighted kappa of 0.811.DiscussionOur findings suggest that self-reported fitness, as assessed by the IFIS, is a valid, reliable, and health-related measure. Furthermore, it can be a good alternative for future use in large studies with Latin schoolchildren from Colombia.

ObjectiveThis study aimed to compare the effects of two frequencies of high-speed resistance training (HSRT) on physical performance and quality of life of older women.MethodsA total of 24 older women participated in a 12-week HSRT program composed of either two or three sessions/week (equated for volume and intensity). Women were randomized into three arms: a control group (CG, n=8), a resistance training group performing two sessions/week (RT2, n=8), and a resistance training group performing three sessions/week (RT3, n=8). The training program for both experimental groups included exercises that required high-speed concentric muscle actions.ResultsNo baseline differences were observed among groups. Compared with the CG, both training groups showed similar small to moderate improvements (P<0.05) in muscle strength, power, functional performance, balance, and quality of life.ConclusionThese results suggest that equated for volume and intensity, two and three training sessions/week of HSRT are equally effective for improving physical performance and quality of life of older women.

The purpose of this study was to compare the inter-individual variability in the effects of plyometric jump training (PJT) on measures of physical fitness (sprint time, change of direction speed, countermovement jump, 20- and 40-cm drop jump reactive strength index, multiple five bounds distance, maximal kicking distance, and 2.4-km time trial) in youth soccer players who completed a PJT program versus players who completed soccer training only. In a single-blinded study, participants aged between 10 and 16 years were randomly divided into a PJT group (n = 38) and a control group (n = 38). The experimental group participated in a PJT program twice weekly for 7 weeks, whereas the control group continued with their regular soccer training sessions. Between-group differences were examined using a Mann–Whitney U test. Nonresponders where defined as individuals who failed to demonstrate any beneficial change that was greater than two times the typical error of measurement from zero. The results indicated that the mean group improvement for all physical fitness measures was greater (p < 0.05) in the PJT group (Δ = 0.4 to 23.3%; ES = 0.04 to 0.58) than in the control group (Δ = 0.1 to 3.8%; ES = 0.02 to 0.35). In addition, a significantly greater (p < 0.05) number of responders across all dependent variables was observed in the PJT group (from 4 up to 33 responders) than in the control group (from 0 up to 9 responders). In conclusion, compared to soccer training only, PJT induced greater physical fitness improvements in youth soccer players, with a greater number of responders for all the physical fitness tests related to jumping, speed, change of direction speed, endurance, and kicking technical ability.