Some evidence suggests that physical activity programs might promote short-term weight gain and bone mineralization in preterm infants .
Current evidence does not support the routine use of physical activity programs in preterm infants .
BACKGROUND Lack of physical stimulation may contribute to metabolic bone disease of preterm infants , result ing in poor bone mineralization and growth .
Physical activity programs combined with adequate nutrition might help to promote bone mineralization and growth .
OBJECTIVES The primary objective was to assess whether physical activity programs in preterm infants  improve bone mineralization and growth and reduce the risk of fracture .
Subgroup analysis : • Given that the smallest infants are most vulnerable for developing osteopenia ( Bishop 1999 ) , a subgroup analysis was planned for infants with birth weight < 1000 g.•  Calcium and phosphorus intake may affect an infant 's ability to increase bone mineral content ( Kuschel 2004 ) .
Daily Physical Activity Program Increases Bone Mineralization and Growth in Preterm Very Low Birth Weight Infants
Objective . A study of daily physical activity was performed with 32 preterm infants to evaluate changes in body weight and bone mineralization . Study Design . Subjects were matched by birth weight and gestational age and r and omly assigned to the  physical activity ( PA;n = 16 ) or to the control  ( C ; n= 16 ) program . PA consisted of range of motion against passive resistance to all extremities for 5 to 10 minutes daily . Peripheral dual-energy x-ray of the right forearm ( ulna and radius ) ; biomarkers of bone formation ( serum type I collagen C-terminal propeptide [ PICP ] ) and resorption ( urine pyridinoline cross-links of collagen [ Pyd ] ) ; serum calcium , phosphate , alkaline phosphatase , parathyroid hormone ( PTH ) , and 1,25-(OH)2 vitamin D ; and urine levels of calcium , phosphate , and creatinine were obtained . All measurements were made at study entry and at 2.0 kg of body weight . Results . Despite a similar nutrient intake at advised levels for preterm infants , gains in body weight ( g ) and forearm bone length ( cm ) , bone area ( BA ; cm2 ) , bone mineral content ( BMC ; mg ) , and fat-free mass ( g ) were greater in PA infants . Forearm bone mineral density and fat mass gains did not differ between groups . Serum PICP levels remained constant in PA infants but decreased in C infants suggesting a slower rate of bone formation . Urine Pyd or bone resorption activity was similar between groups . A higher level of serum PTH was observed in PA infants at 2.0 kg of body weight ; however , the change from study entry to completion did not differ between groups . All other serum and urine values were similar and within normal limits . Conclusion . A daily PA program promotes greater gains in body weight , forearm length , BA , BMC , and fat-free mass in premature infants
Some evidence suggests that physical activity programs might promote short-term weight gain and bone mineralization in preterm infants .
Current evidence does not support the routine use of physical activity programs in preterm infants .
BACKGROUND Lack of physical stimulation may contribute to metabolic bone disease of preterm infants , result ing in poor bone mineralization and growth .
Physical activity programs combined with adequate nutrition might help to promote bone mineralization and growth .
OBJECTIVES The primary objective was to assess whether physical activity programs in preterm infants  improve bone mineralization and growth and reduce the risk of fracture .
Subgroup analysis : • Given that the smallest infants are most vulnerable for developing osteopenia ( Bishop 1999 ) , a subgroup analysis was planned for infants with birth weight < 1000 g.•  Calcium and phosphorus intake may affect an infant 's ability to increase bone mineral content ( Kuschel 2004 ) .