COVID-19 vaccine hesitancy among youth

The purpose of this evaluation is to describe COVID-19 vaccine hesitancy among a sample of youth aged 12-15 and inform efforts to increase vaccination uptake among youth populations. We used data collected in May 2021 through a health education program for 9^th graders (N = 345). We used Spearman correlations and chi-square tests to assess the statistical significance of bivariate relationships. Less than half of students (42%) reported they are not hesitant at all about getting a COVID-19 vaccine. The remainder reported they were "a little hesitant" (22%), "somewhat hesitant" (21%), or "very hesitant" (15%). There were no statistically significant differences across age, gender, race/ethnicity, parental education, self-reported grades, or hours playing video games during school days. There was a statistically significant relationship between COVID-19 vaccine hesitancy and hours of TV watched during school days. The prevalence of COVID-19 vaccine hesitancy in this sample is high, but more research is needed to estimate its prevalence for youth at the state or national level. Correlates of COVID-19 vaccine hesitancy among adult populations may not match those found in youth populations. Research which recognizes youth as agentic rather than passive participants in decision-making opens opportunities for developing age-appropriate health communication and interventions for vaccination.

The role of volume-load in strength and absolute endurance adaptations in adolescent's performing high- or low-load resistance training

This study compared high- (HL) and low-load (LL) resistance training (RT) on strength, absolute endurance, volume-load, and their relationships in untrained adolescents. Thirty-three untrained adolescents of both sexes (males, n = 17; females, n = 16; 14 ± 1 years) were randomly assigned into either (i) HL (n = 17): performing 3 sets of 4-6 repetitions to momentary concentric failure; or (ii) LL (n = 16): performing 2 sets of 12-15 repetitions to momentary concentric failure. RT was performed for 2×/week for 9 weeks. Change in maximum strength (1 repetition maximum) and absolute muscular endurance for barbell bench press was assessed. Weekly volume-load was calculated as sets (n) × repetitions (n) × load (kg). Ninety-five percent confidence intervals (CIs) revealed that both groups significantly increased in strength and absolute endurance with large effect sizes (d = 1.51-1.66). There were no between-group differences for change in strength or absolute endurance. Ninety-five percent CIs revealed that both groups significantly increased in weekly volume-load with large effect sizes (HL = 1.66, LL = 1.02). There were no between-group differences for change in volume-load though average weekly volume-load was significantly greater for LL (p < 0.001). Significant Pearson's correlations were found for the HL group between average weekly volume-load and both strength (r = 0.650, p = 0.005) and absolute endurance (r = 0.552, p = 0.022) increases. Strength and absolute endurance increases do not differ between HL and LL conditions in adolescents when performed to momentary concentric failure. Under HL conditions greater weekly volume-load is associated with greater strength and absolute endurance increases.