Physical activity habits associated with health variables in Chilean male school children / Hábitos de actividad física asociados a variables de salud en escolares chilenos varones

Introduction: Physical inactivity is a factor that con-tributes to increased cardiometabolic risk, such as overweightand obesity in schoolchildren.Aim: To associate physical activity habits with morphologi-cal variables (body mass index [BMI], waist circumference[WC], body fat, and fat-free mass), blood pressure, glycemia,handgrip strength (HGS), and countermovement jump (CMJ)in Chilean male schoolchildren. In addition, to compare phys-ically active (PA) schoolchildren to physically inactive (PI)schoolchildren on morphological variables, blood pressure,glycemia, HGS, and CMJ. Material and methods: A cross-sectional study analyzed160 schoolchildren with a mean age of 7.12 ± 4.5 years dis-tributed into PA schoolchildren (n=75) and PI schoolchildren(n=85). A logistic regression was performed to identify theassociation between physical activity habits with factors ofmorphological variables (BMI, WC, body fat, and fat-freemass), blood pressure, glycemia, HGS, and CMJ. In addition,to compare the differences in physical activity habits (physi-cally active vs. physically inactive), a student’s t-test was per-formed for independent samples. Results: Logistic regression showed that physical activityis protective factor against excess body fat of 46% (OR=0.46; 95%CI= 0.22 to 0.95; p= 0.03), hyperglycemia of 25%(OR= 0.25; 95%CI= 0.12 to 0.51; p< 0.0001), high bloodpressure of 31% (OR= 0.31; 95%CI= 0.15 to 0.67; p=0.002), and HGS dominant hand of 40% (OR= 0.40; 95%CI=0.19 to 0.83; p= 0.014). Conclusion: Physical activity protected against excessbody fat, hyperglycemia, hypertension, and decreased HGSin Chilean male schoolchildren. PA schoolchildren exhibitedlower body fat, reduced risk of hyperglycemia and hyper-tension, and improved HGS and CMJ compared to PI school-children.(AU)

Introducción: La inactividad física es un factor que contribuye al aumento del riesgo cardiometabólico, como el sobrepeso y la obesidad en escolares.Objetivo: Asociar los hábitos de actividad física con variables morfológicas (índice de masa corporal [IMC], circunferencia de cintura [CC], grasa corporal y masa libre de grasa), presión arterial, glucemia, fuerza de prensión manual (FPM) y salto con contramovimiento (CMJ) en escolares hombres chilenos. Además, comparar escolares físicamente activos (FA) con escolares físicamente inactivos (FI) en variables morfológicas, presión arterial, glucemia, FPM y CMJ.Material y métodos: Estudio transversal que analizó 160 escolares con una edad media de 7,12 ± 4,5 años distribuidos en escolares FA (n= 75) y escolares FI (n= 85). Se realizó una regresión logística para identificar la asociación entre los hábitos de actividad física con factores de las variables morfológicas (IMC, CC, grasa corporal y masa libre de grasa), presión arterial, glucemia, FPM y CMJ. Además, para comparar las diferencias en los hábitos de actividad física (físicamente activos vs. físicamente inactivos), se realizó la prueba t de Student para muestras independientes.Resultados: La regresión logística mostró que la actividad física es un factor protector contra el exceso de grasa corporal en un 46% (OR= 0,46; IC95%= 0,22 a 0,95; p= 0,03), hiperglucemia en un 25% (OR= 0,25; IC95%= 0,12 a 0,51; p< 0,0001), hipertensión arterial del 31% (OR= 0,31; IC95%= 0,15 a 0,67; p= 0,002), y FPM en mano dominante del 40% (OR= 0,40; IC95%= 0,19 a 0,83; p= 0,014).Conclusión: La actividad física protegió contra el exceso de grasa corporal, la hiperglucemia, la hipertensión arterial y la disminución de FPM en escolares hombres chilenos. Los escolares FA exhibieron menos grasa corporal, menor riesgo de hiperglucemia e hipertensión, y FPM, además de CMJ mejorados en comparación con los escolares FI.(AU)

Corrigendum: Warm-up stretching exercises and physical performance of youth soccer players.

[This corrects the article DOI: 10.3389/fphys.2023.1127669.].

Warm-up stretching exercises and physical performance of youth soccer players.

This study aims to compare the effects of standard warm-up versus warm-up using stretching exercises on the physical performance of male youth soccer players. Eighty-five male soccer players (age: 10.3 ± 4.3 years; body mass index: 19.8 ± 4.3 kg/m2) were assessed for countermovement jump height (CMJ, cm), 10 m, 20 m and 30 m running sprint speed (s) and ball kicking speed (km/h) for the dominant and non-dominant leg under five (randomized) warm-up conditions. Using 72 h of recovery between conditions, the participants completed a control condition (CC) and four experimental conditions, including static stretching (SSC), dynamic stretching (DSC), ballistic stretching (BSC), and proprioceptive neuromuscular facilitation (PNFC) exercises. All warm-up conditions had a duration of 10 minutes. The main results indicate that no significant differences (p > 0.05) were found between warm-up conditions compared to CC in CMJ (CC = 28.1 ± 4.9; SSC = 28.4 ± 4.9; DSC = 30.9 ± 4.8; BSC = 30.9 ± 5.2; PNFC = 28.4 ± 5.0), 10 m sprint (CC = 2.42 ± 0.4; SSC = 2.50 ± 0.4; DSC = 2.30 ± 0.3; BSC = 2.27 ± 0.3; PNFC = 2.53 ± 0.4), 20 m sprint (CC = 5.42 ± 0.9; SSC = 5.59 ± 0.9; DSC = 5.37 ± 0.9; BSC = 5.40 ± 0.9; PNFC = 5.44 ± 0.9), 30 m sprint (CC = 8.05 ± 1.3; SSC = 8.27 ± 1.3; DSC = 8.01 ± 1.3; BSC = 8.00 ± 1.3; PNFC = 8.12 ± 1.3), ball kicking speed for dominant (CC = 56.2 ± 4.9; SSC = 55.3 ± 5.2; DSC = 56.9 ± 5.8; BSC = 57.3 ± 5.8; PNFC = 55.7 ± 5.2) and non-dominant leg (CC = 52.8 ± 3.4; SSC = 51.8 ± 4.6; DSC = 53.5 ± 5.4; BSC = 53.6 ± 4.9; PNFC = 52.5 ± 4.0). In conclusion, compared to standard warm-up, stretching-based warm-up exerts no effect on male youth soccer players jump height, sprint speed and ball kicking speed.

Warm-Up and Handgrip Strength in Physically Inactive Chilean Older Females According to Baseline Nutritional Status.

This study aims to analyze the effect of different types of warm-ups on handgrip strength (HGS) in physically inactive older females. Secondarily, it aims to compare HGS according to their baseline nutritional status. A randomized crossover trial study was conducted with 44 physically inactive older females distributed into normal weight (n = 12, BMI = 23.9 ± 3.2 kg/m2), overweight (n =16, BMI = 27 ± 4.7 kg/m2) and obese (n = 16, BMI = 31.6 ± 5.3 kg/m2), who participated in three warm-up conditions (static stretching condition, SSC; elastic band condition, EBC; and therapeutic compression ball condition, TCBC) and one control condition (CC, no warm-up). All participants performed the four randomized conditions with recovery within 72 h. A significant decrease (p < 0.05) in HGS for the dominant and non-dominant hands was observed when comparing SSC vs. CC. In contrast, comparing the warm-up conditions according to the baseline nutritional status, statistically significant differences (p < 0.05) were only reported in the obese group in the dominant and non-dominant hand in favor of CC concerning SSC. In conclusion, warm-up with static flexibility led to a decrease in HGS in physically inactive older females. Only the obese group exhibited this result when analyzed by nutritional status.

Effects of Maturation on Physical Fitness Adaptations to Plyometric Drop Jump Training in Male Youth Soccer Players.

Vera-Assaoka, T, Ramirez-Campillo, R, Alvarez, C, Garcia-Pinillos, F, Moran, J, Gentil, P, and Behm, D. Effects of maturation on physical fitness adaptations to plyometric drop jump training in male youth soccer players. J Strength Cond Res 34(10): 2760-2768, 2020-The objective of this study was to compare the effects of maturation on physical fitness adaptations to a twice weekly, 7-week plyometric drop jump training program. Seventy-six young male soccer players (aged 10-16 years) participated in this randomized controlled trial. Before and after the intervention, a physical fitness test battery was applied (countermovement jump; drop jump from 20 to 40 cm; 5 multiple bounds test; 20-m sprint time; change of direction speed; 2.4-km running time-trial; 5 repetition maximum [RM] squat; and maximal kicking distance). Participants were randomly divided into an active soccer-control group (CG) with Tanner stage maturation of 1-3 (CG-early; n = 16) or Tanner stage 4-5 (CG-late; n = 22), and to plyometric drop jump training groups with Tanner stage 1-3 (plyometric jump training [PJT]-early; n = 16) or 4-5 (PJT-late; n = 22). The analysis of variance and effect size (ES) measures revealed that when compared with their age-matched controls, the PJT-early (ES = 0.39-1.58) and PJT-late (ES = 0.21-0.65) groups showed greater improvements (p < 0.05) in sprint time, 2.4-km running time-trial, change of direction speed, 5RM squat, jumping, and kicking distance. The PJT-early exceeded the PJT-late group with greater (p < 0.05) improvements in drop jump from 20 cm (ES = 1.58 vs. 0.51) and 40 cm (ES = 0.71 vs. 0.4) and kicking distance (ES = 0.95 vs. 0.65). Therefore, a 7-week plyometric drop jump training program was effective in improving physical fitness traits in both younger and older male youth soccer players, with greater jumping and kicking adaptations in the less-mature athletes.