Birthweight, body composition, and motor performance in 7- to 10-year-old children.

AIM: The aim of this study was to analyse the influence of birthweight on motor performance and body composition in children. Further, we investigated whether associations between birthweight and motor performance changed after adjustment for current height, body mass index (BMI), fat-free mass (FFM), and % body fat. METHOD: A total of 483 children (251 males and 232 females) aged 7 to 10 years (mean 8.78, SD 1.0y) born in Vitória Santo Antão (northeast Brazil) were sampled. Motor performance was operationalized using different physical fitness components and gross motor coordination. Physical fitness was measured by handgrip strength, muscle endurance, explosive power, flexibility, agility, running speed, and maximal oxygen consumption (VO2max). Gross motor coordination was evaluated by means of the Körper Koordination Test für Kinder (KTK). RESULTS: Positive correlations between birthweight and height, BMI, and FFM were found. Birthweight was positively correlated with handgrip strength and negatively correlated with 20-meter sprint time, even after controlling for age, height, BMI, FFM, and % body fat. Birthweight was negatively associated with relative VO2max (mL/kg/min); however, the association was no longer significant after inclusion of BMI or FFM in the model. INTERPRETATION: Birthweight significantly predicted height, BMI, FFM, and performance in strength and velocity tests, but did not influence gross motor coordination.

Maternal low-protein diet-induced delayed reflex ontogeny is attenuated by moderate physical training during gestation in rats.

We evaluated the effects of moderate- to low-intensity physical training during gestation on reflex ontogeny in neonate rats whose mothers were undernourished. Virgin female Wistar rats were divided into four groups as follows: untrained (NT, n 7); trained (T, n 7); untrained with a low-protein diet (NT+LP, n 7); trained with a low-protein diet (T+LP, n 4). Trained rats were subjected to a protocol of moderate physical training on a treadmill over a period of 4 weeks (5 d/week and 60 min/d, at 65 % of VO2max). After confirming the pregnancy, the intensity and duration of the exercise were reduced. Low-protein groups were provided with an 8 % casein diet, and controls were provided with a 17 % casein diet. Their respective offspring were evaluated (during the 10th-17th days of postnatal life) in terms of physical feature maturation, somatic growth and reflex ontogeny. Pups born to mothers provided with the low-protein diet during gestation and lactation showed delayed physical feature and reflex maturation and a deficit in somatic growth when compared with controls. However, most of these deficiencies were attenuated in pups of undernourished mothers undergoing training. In conclusion, physical training during gestation attenuates the effects of perinatal undernutrition on some patterns of maturation in the central nervous system during development.