Cardiovascular adaptations after 10 months of daily 12-min bouts of intense school-based physical training for 8-10-year-old children.

The present study examined cardiovascular adaptations in 8-10-year-old schoolchildren after a full school year (10 months) of 5 × 12 min/wk. of intense physical training, including small-sided ball games (soccer, basketball and floorball) or interval running. The study involved 8-10-year-old healthy Danish schoolchildren (n = 232), who were cluster-randomized to a small-sided games group (SSG, n = 60), an interval running group (IR, n = 57) or a control group (CON, n = 115). Comprehensive transthoracic echocardiography, resting heart rate and blood pressure measurements were performed at baseline and post intervention. For interval running, analysis of baseline-to-10-months changes showed significant (P < 0.05) between-group differences in delta scores for diastolic blood pressure (BP) and mean arterial BP (IR -3.2 ±â€¯5.7 and - 2.2 ±â€¯6.5 mmHg vs. CON 0.2 ±â€¯5.3 and 0.4 ±â€¯6.4 mmHg, respectively). Delta scores also showed a trend for reduction of mean arterial BP in SSG compared to CON (-2.1 ±â€¯6.0 vs. 0.2 ±â€¯5.3 mmHg, P = 0.067). Moreover, there were between-group differences in delta scores (P < 0.05) for selected echocardiographic parameters, i.e. in SSG vs. CON for interventricular septum thickness and peak transmitral flow velocity in early diastole, and in IR vs. CON for left ventricular systolic diameter. In conclusion, 10 months of 5 × 12 min/wk. of IR in 8-10-year-old children decreased diastolic BP, while both IR and SSG elicited cardiac adaptations. The results suggest that frequent low volume, intense physical training can have effects on the cardiovascular health profile in healthy children.

Cardiovascular adaptations after 10 months of intense school-based physical training for 8- to 10-year-old children.

This study examined cardiovascular adaptations in 8- to 10-year-old schoolchildren after 10 months (a full school year) of 3 × 40 minute per week of small-sided ball games (SSG, including football, basketball, and/or floorball) or circuit strength training (CST). The study involved 291 Danish schoolchildren, 8-10 years old, cluster-randomized to SSG (n = 93, 4 schools, 5 classes), CST (n = 83, 4 schools, 4 classes), or a control group (CON, n = 115, 2 schools, 5 classes). Before and after the 10-month intervention, resting heart rate and blood pressure measurements were performed as well as comprehensive transthoracic echocardiography and peripheral arterial tonometry (PAT). Analysis of baseline-to-10-months changes showed between-group differences (P < 0.05) after both training interventions in diastolic blood pressure (delta scores: SSG -2.1 ± 6.0 mm Hg; CST -3.0 ± 7.1 mm Hg; CON 0.2 ± 5.3 mm Hg). Moreover, there were between-group differences in delta scores (P < 0.05) in interventricular septum thickness (SSG 0.17 ± 0.87 mm; CST 0.30 ± 0.94 mm; CON -0.15 ± 0.68 mm), left-atrial volume index (SSG 0.32 ± 5.13 mL/m2 ; CON 2.60 ± 5.94 mL/m2 ), and tricuspid annular plane systolic excursion (SSG -0.4 ± 3.3 mm; CON: 0.1 ± 3.6 mm). No significant between-group differences were observed for the PAT-derived reactive hyperemia index. In conclusion, 10 months of 3 × 40 minutes per week of SSG and CST in 8- to 10-year-old children decreased diastolic blood pressure and elicited discrete cardiac adaptations, suggesting that intense physical exercise in school classes can have effects on cardiovascular health in children.

Positive effects on bone mineralisation and muscular fitness after 10†months of intense school-based physical training for children aged 8-10†years: the FIT FIRST randomised controlled trial.

OBJECTIVES: We investigated whether musculoskeletal fitness of school children aged 8-10 years was affected by frequent intense PE sessions. DESIGN AND PARTICIPANTS: 295 Danish school children aged 8-10 years were cluster randomised to a small-sided ball game group (SSG) (n=96, four schools, five classes), a circuit strength training group (CST) (n=83, four schools, four classes) or a control group (CON, n=116, two schools, five classes). INTERVENTION: SSG or CST was performed 3×40 min/week over 10 months. Whole-body dual-energy X-ray absorptiometry (DXA) scans were used to determine areal bone mineral density (aBMD), bone mineral content (BMC) and lean body mass (LBM). Flamingo balance, standing long jump and 20-m sprint tests were used to determine muscular fitness. RESULTS: Analysis of baseline-to-10 months change scores showed between-group differences in favour of the interventions in whole-body aBMD (SSG vs CON: 8 mg/cm2, 95% CI 3 to 13; CST vs CON: 7 mg/cm2, 95% CI 2 to 13, p<0.05) and leg BMC (SSG vs CON: 11 g, 95% CI 4 to 18; CST vs CON: 11 g, 95% CI 3 to 18, p<0.05). SSG had higher change scores in leg aBMD compared with CON and CST (SSG vs CON: 19 mg/cm2, 95% CI 11 to 39, p<0.05; SSG vs CST: 12 mg/cm2, 95% CI 3 to 21, p<0.05), and CST had higher change scores in whole-body BMC compared with CON (CST vs CON: 25 g, 95% CI 10 to 39, p<0.05). Both training types resulted in higher change scores in postural balance (SSG vs CON: 2.4 fewer falls/min, 95% CI 0.3 to 4.5, CST vs CON: 3.6 fewer falls/min, 95% CI 1.3 to 5.9, p<0.05) and jump length (SSG vs CON: 10%, 95% CI 5 to 16%; CST vs CON: 9%, 95% CI 3 to 15%, p<0.05). No between-group differences were observed for sprint performance or LBM (p>0.05). CONCLUSIONS: In conclusion, 3×40 min/week with SSG or CST over a full school year improves bone mineralisation and several aspects of muscular fitness of children aged 8-10 years, suggesting that well-organised intense physical education classes can contribute positively to develop musculoskeletal health in young children. TRIAL REGISTRATION NUMBER: NCT02000492, post results.

Physical Fitness and Body Composition in 8-10-Year-Old Danish Children Are Associated With Sports Club Participation.

Larsen, MN, Nielsen, CM, Ørntoft, CØ, Randers, M, Manniche, V, Hansen, L, Hansen, PR, Bangsbo, J, and Krustrup, P. Physical fitness and body composition in 8-10-year-old Danish children are associated with sports club participation. J Strength Cond Res 31(12): 3425-3434, 2017-We investigated whether physical fitness and body composition in 8-10-year-old Danish children are associated with sports club participation. The study included 423 schoolchildren, comprising 209 girls and 214 boys, of whom 67 and 74%, respectively, were active in sports clubs. Yo-Yo intermittent recovery level 1 for children (YYIR1C), balance, jump and coordination tests, together with dual-energy X-ray absorptiometry, were used to determine exercise capacity and body composition. Children active in sports clubs had better (p < 0.05) YYIR1C (33%, 767 ± 26 vs. 575 ± 29 m), 20-m sprint (3%, 4.33 ± 0.03 vs. 4.48 ± 0.04 seconds), coordination (6%, 68 ± 1 vs. 72 ± 1 second), and balance test performances (9%, 19.3 ± 0.5 vs. 21.2 ± 0.7 falls·min) and lower fat mass index (16%, 3.8 ± 0.1 vs. 4.5 ± 0.2 kg[fat]·m) than children not active in sports clubs. Ball game players had better (p < 0.05) YYIR1C (38%, 925 ± 39 vs. 671 ± 28 m), 20-m sprint (4%, 4.25 ± 0.03 vs. 4.42 ± 0.04 seconds), and coordination test performances (5%, 65 ± 1 vs. 69 ± 1 second), along with higher (p < 0.05) lean body mass (5%, 24.00 ± 0.22 vs. 22.83 ± 0.25 kg) and whole-body BMD (2%, 0.90 ± < 0.01 vs. 0.88 ± <0.01 g·cm) compared with children active in other sports. The study showed that 8[FIGURE DASH]10-year-old Danish children engaged in sports-club activity, especially ball game players, have better exercise capacity and superior body composition compared with children not active in sports clubs.

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

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.