Effects of Strength Training on Sleep Parameters of Adolescents: A Randomized Controlled Trial.

ABSTRACT: Santiago, LCS, Lyra, MJ, Germano-Soares, AH, Lins-Filho, OL, Queiroz, DR, Prazeres, TMP, Mello, MT, Pedrosa, RP, Falcão, APST, and Santos, MAM. Effects of strength training on sleep parameters of adolescents: a randomized controlled trial. J Strength Cond Res 36(5): 1222-1227, 2022-This study aimed to examine the effects of 12 weeks of strength training (ST) on sleep quality and daytime sleepiness in adolescents with sleep complaints. Thirty adolescents were randomly assigned to 2 groups: ST group (ST, n = 18) and control group (CG, n = 12). Anthropometric, body composition, one-repetition maximum test, and sleep parameters (Pittsburgh Sleep Quality Index [PSQI] and Epworth Sleepiness Scale [ESS]) were evaluated. Training consisted of 55 min·d-1 (3 times a week, for 12 weeks), 3 sets of 10-12 repetitions with a 1-minute rest interval between sets and exercises. Baseline and postintervention differences were analyzed using Generalized Estimating Equations and the effect size (ES) with Cohen's d coefficient. Significance was set at (p < 0.05). After 12 weeks of ST, a significant decrease in the PSQI score (7.3 ± 0.7 vs. 5.1 ± 0.6; ES = 4.10) was observed in the ST group, but not in the CG (6.3 ± 0.8 vs. 7.4 ± 0.7; ES = 1.53). A significant decrease in ESS score was found in the ST group (10.1 ± 0.7 vs. 8.2 ± 0.7; ES = 3.08), without differences in the CG (10.7 ± 0.8 vs. 11.0 ± 0.7; ES = 0.56). The ST group presented increased total sleep duration (h·min-1) (6.2 ± 0.2 vs. 6.9 ± 0.2; ES = 3.60), but not the CG (7.0 ± 0.2 vs. 6.8 ± 0.1; ES = 1.32). Individual analyses showed ≈67% of adolescents experienced a reduction in PSQI (8.3; confidence interval [CI] 95% 6.8-10.1) and ESS (8.3; CI 95% 6.7-9.9) scores after ST, whereas only ≈17% of control subjects presented reduced scores (PSQI [11.1; CI 95% 9.5-12.9] and ESS [11.0; CI 95% 9.4-12.6]). Strength training improved sleep quality and increased total sleep duration.

Is motor competence associated with the risk of central obesity in preschoolers?

OBJECTIVES: To investigate the association between motor competence (MC) and central obesity in preschool children. METHODS: The sample comprised of 472 children aged 3 to 5 years (4.58 ± 0.70 years, 248 boys) from Recife, Brazil. MC was assessed using the Test of Gross Motor Development-2. Waist-to-height ratio (WHtR) was calculated and a cutoff of 0.5 was used to define central obesity. Logistic regression was used to examine the association between MC and WHtR ≥ 0.5. RESULTS: The prevalence of central obesity (WHtR) was 54.0% and 46.4% for boys and girls, respectively. Older children (OR = 0.61; CI = 0.44-0.84; P < .01) and those with higher MC in locomotor skills (OR = 0.96; CI = 0.93-0.99; P < .01) were less likely to present WHtR ≥ 0.5. Sex and object control skills were not associated with WHtR ≥ 0.5. CONCLUSIONS: To reduce the risks of central obesity in children, health practitioners should focus on increasing competence in locomotor skills since preschool years.

Rating of Perceived Exertion During Circuit Weight Training: A Concurrent Validation Study.

The aim of this study was to determine whether rating of perceived exertion (RPE) is a valid method to control the effort during the circuit weight training (CWT) in trained men. Ten men (21.3 ± 3.3 years) with previous experience in resistance training (13.1 ± 6.3 months) performed 3 sessions: 1 orientation session and 2 experimental sessions. The subjects were randomly counterbalanced to 2 experimental sessions: CWT or multiple-set resistance training (control). In both sessions, 8 exercises (bench press, leg press 45°, seated row, leg curl, triceps pulley, leg extension, biceps curl, and adductor chair) were performed with the same work: 60% of 1 repetition maximum, 24 stations (3 circuits) or 24 sets (3 sets/exercise), 10 repetitions, 1 second in the concentric and eccentric phases, and rest intervals between sets and exercise of 60 seconds. Active muscle RPEs were measured after each 3 station/sets using the OMNI-Resistance Exercise Scale (OMNI-RES). In this same time, blood lactate was collected. Compared with baseline, both levels of blood lactate and RPE increased during whole workout in both sessions, the RPE at third, 23rd, and 27th minute and the blood lactate at third, seventh, 11th, 15th, 27th, and 31st minute were higher in multiple set compared with CWT. Positive correlation between blood lactate and RPE was observed in both experimental sessions. The results indicated that the RPE is a valid method to control the effort during the CWT in trained men and can be used to manipulate the intensity without the need to perform invasive assessments.