Key messages
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In preterm infants, physical activity programmes may provide a small benefit for bone development and body weight gain over the short term.
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Physical activity programmes may have little to no effect on body length gain.
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We do not know if physical activity programmes affect the risk of fractures (broken bones), and we don't have enough information to assess long-term benefits and harm.
What is poor bone development and growth in preterm infants?
Babies born too early (born before 37 weeks of pregnancy) are often cared for in a way that minimises physical activity to reduce stress and stress-related complications. However, lack of physical activity might lead to poor bone development and growth, particularly in very low birth weight infants (meaning babies born weighing less than 1500 g). This may have long-term consequences, as seen in bedridden children and adults.
What are physical activity programmes?
Physical activity programmes are daily exercise where all joints in the arms and legs are gently moved and pressed for a few minutes each day over several weeks.
What is bone mineralisation?
Bone mineralisation is the process in which minerals, mainly calcium and phosphorus, are added to newly formed bone tissue, making the bone hard and strong.
What did we want to find out?
We wanted to find out whether physical activity programmes given during the initial hospital stay help preterm infants to develop stronger bones and grow better. We planned to assess this at the end of the programme and 12 to 24 months after the expected date of delivery. We also wished to examine whether these programmes affect the risk of fractures (broken bones).
What did we do?
We searched for studies that compared physical activity programmes with no organised programmes in preterm infants.
What did we find?
We included 15 small studies, with 434 infants, in our review.
We found that preterm infants who received a daily physical activity programme for several weeks might have slightly better bone mineralisation and gain in body weight when assessed at completion of the programme, but we are uncertain about the results.
We don't know whether physical activity programmes have a long-term effect on bone mineral content, because none of our included studies gave information on this outcome. We found no evidence that the physical activity programmes reduced or increased body length. We found very uncertain evidence regarding their effect on the frequency of fractures.
What are the limitations of the evidence?
Our confidence in the results is low to very low because many of the included studies were small or had limitations in their methods. When several studies were combined for specific outcomes, the results were often imprecise and inconsistent. Because of this, we are uncertain whether physical activity programmes have meaningful effects on bone mineralisation, weight gain, body length gain or the risk of a fracture.
The evidence only covers outcomes measured during the initial hospital stay, and we do not have evidence about longer-term effects.
How up to date is this evidence?
This review updates our previous review from 2014. The evidence is up to date as of October 2025.
Pročitajte cijeli sažetak
Uvod
Lack of physical stimulation may contribute to metabolic bone disease of preterm infants, resulting in poor bone mineralization and growth. Physical activity programs combined with adequate nutrition might help to promote bone mineralization and growth.
Ciljevi
The primary objective was to assess whether physical activity programmes in preterm infants improve bone mineralisation and growth and reduce the risk of fractures.
The secondary objectives included assessment of other potential benefits in terms of complications of preterm birth, length of hospital stay, skeletal deformities, neurodevelopmental outcomes and adverse events.
Metode pretraživanja
We searched CENTRAL, MEDLINE, Embase and trial registries in October 2025. We checked the reference lists of included studies and systematic reviews where the subject matter related to the intervention or population examined in this review.
Kriteriji odabira
Randomized and quasi-randomized controlled trials comparing physical activity programs (extension and flexion, range-of-motion exercises) versus no organized physical activity programs in preterm infants.
Prikupljanje podataka i obrada
Data collection, study selection, and data analysis were performed according to the methods of the CNRG.
Glavni rezultati
Eleven trials enrolling 324 preterm infants (gestational age 26 to 34 weeks) were included in this review. All were small (N = 16 to 50) single-center studies that evaluated daily physical activity for three and one-half to eight weeks during initial hospitalization. Methodological quality and reporting of included trials were variable.
Four trials demonstrated moderate short-term benefits of physical activity for bone mineralization at completion of the physical activity program. The only trial assessing long-term effects on bone mineralization showed no effect of physical activity administered during initial hospitalization on bone mineralization at 12 months corrected age. Meta-analysis from four trials demonstrated a positive effect of physical activity on daily weight gain (weighted mean difference (WMD) 2.21 g/kg/d, 95% confidence interval (CI) 1.23 to 3.19). Data from four trials showed a positive effect on linear growth (WMD 0.12 cm/wk, 95% CI 0.01 to 0.24) but not on head growth (WMD -0.03 cm/wk, 95% CI -0.14 to 0.08) during the study period. Only one trial reported on fractures (this outcome did not occur in intervention and control groups) and complications of preterm birth (no significant differences between intervention and control groups). None of the trials assessed other outcomes relevant to this review.
Zaključak autora
There is low to very low-certainty evidence on the effect of physical activity programmes, compared to no standardised programmes, on bone mineralisation and growth in preterm infants. Physical activity programmes may increase whole‑body bone mineral density and body weight gain, and may have little to no effect on body length gain compared to no standardised programmes. It is very uncertain whether physical activity programmes have any effect on whole‑body mineral content or the risk of fractures. No adequate data are available on bone mineralisation at 12 to 24 months' corrected age.
Given the low to very low-certainty evidence for all outcomes, further large, well-designed RCTs are needed to assess the effects of physical activity programmes on bone mineralisation and growth in preterm infants.
Funding
This Cochrane review had no dedicated funding.
Registration
Protocol (2005) DOI 10.1002/14651858.CD005387
Original review (2007) DOI 10.1002/14651858.CD005387.pub2
Review update (2014) DOI 10.1002/14651858.CD005387.pub3
