Fitness Effects of 10-Month Frequent Low-Volume Ball Game Training or Interval Running for 8–10-Year-Old School Children

Abstract EN

We investigated the exercise intensity and fitness effects of frequent school-based low-volume high-intensity training for 10 months in 8–10-year-old children.

239 Danish 3rd-grade school children from four schools were cluster-randomised into a control group (CON, n=116) or two training groups performing either 5×12 min/wk small-sided football plus other ball games (SSG, n=62) or interval running (IR, n=61).

Whole-body DXA scans, flamingo balance, standing long-jump, 20 m sprint, and Yo-Yo IR1 children’s tests (YYIR1C) were performed before and after the intervention.

Mean running velocity was higher (p<0.05) in SSG than in IR (0.88±0.14 versus 0.63±0.20 m/s), while more time (p<0.05) was spent in the highest player load zone (>2; 5.6±3.4 versus 3.7±3.4%) and highest HR zone (>90% HRmax; 12.4±8.9 versus 8.4±8.0%) in IR compared to SSG.

After 10 months, no significant between-group differences were observed for YYIR1C performance and HR after 2 min of YYIR1C (HRsubmax), but median-split analyses showed that HRsubmax was reduced (p<0.05) in both training groups compared to CON for those with the lowest aerobic fitness (SSG versus CON: 3.2% HRmax [95% CI: 0.8–5.5]; IR versus CON: 2.6% HRmax [95% CI: 1.1–5.2]).

After 10 months, IR had improved (p<0.05) 20 m sprint performance (IR versus CON: 154 ms [95% CI: 61–241]).

No between-group differences (p>0.05) were observed for whole-body or leg aBMD, lean mass, postural balance, or jump length.

In conclusion, frequent low-volume ball games and interval running can be conducted over a full school year with high intensity rate but has limited positive fitness effects in 8–10-year-old children.