Meet Leo, four and a half years old. He runs around the yard, climbs the play structure and tries to catch the ball his big sister throws to him. Nothing unusual, it seems. Except that Leo was born at 27 weeks of pregnancy, about three months before his due date. At birth, he fit in the palm of a hand, and he spent several weeks in the neonatal intensive care unit.

Today, his parents are asking a simple question: does moving a lot help him develop? This is exactly the question that a team of researchers in Melbourne, Australia, set out to answer in a study published in 2024 in the journal Archives of Disease in Childhood – Fetal and Neonatal Edition.

Why focus on babies born very early?

A baby is considered preterm when born before 37 weeks of pregnancy. Babies born before 30 weeks, like Leo, are among the “very preterm” babies. Thanks to advances in neonatal care, most of these babies now survive. But being born so early means arriving in the world while the brain is still being built.

We have known for a long time that these children are more likely to face certain difficulties as they grow up: problems with motor coordination (clumsiness, trouble catching an object or keeping their balance), challenges with attention or learning, or emotional and social difficulties. Not all children are affected, far from it, and the intensity of these difficulties varies a lot from one child to another.

In children in general, many studies show that physical activity is good for motor development, but also for health, sleep, mood and some cognitive functions. However, we still knew little about this link in children born very preterm, who may need it the most. That is why this study matters.

How was the study done?

The team, led by physiotherapist and researcher Tara FitzGerald (University of Melbourne and Murdoch Children’s Research Institute), followed 123 children born before 30 weeks of pregnancy. These children were recruited at birth and then assessed between 4 and 5 years of corrected age.

To measure physical activity, the researchers used two complementary tools:

• An accelerometer, a small sensor similar to an activity watch, which each child wore for seven days. It objectively records how much the child moves and how intensely.
• A diary kept by the parents during the same week, which made it possible to tell organized activities (swimming or dance lessons, sports) apart from free play (running in the park, climbing, playing outside).

The children’s development was assessed in three areas, using well-established tools:

• Motor skills: with a set of standardized tests (the MABC-2), which measures manual dexterity, balance, and aiming and catching skills (throwing a beanbag at a target, catching a ball), and with a questionnaire completed by parents about their child’s everyday coordination.
• Cognitive skills: with an intelligence scale for preschool children (the WPPSI-IV), which assesses language, reasoning, working memory and processing speed, among other things.
• Social and emotional development: with a well-known questionnaire on the child’s strengths and difficulties (the SDQ), which covers emotions, behaviour, relationships with other children and prosocial behaviour, such as sharing, helping or comforting others.

The researchers then used statistical analyses to check whether more active children had different results from less active children. They also looked at which factors present at birth might be linked to low levels of physical activity a few years later.

What the researchers found

1. Moving more, catching better

The clearest result concerns motor skills. Children who moved more, according to the accelerometer, scored better on the aiming and catching tests. In practical terms, each additional hour of recorded physical activity was linked to an increase of about half a point on the standardized score for this test.

Is that a lot? On this scale, the average score for children is 10, and the usual spread between children (the standard deviation) is 3 points. A gain of half a point per hour of activity is therefore a modest but real effect, and one that can add up. Throwing, aiming and catching are skills that children practise precisely by playing: it makes sense that a child who moves often has more chances to practise them.

2. Active children… who are also more prosocial

The most active children also had better scores for prosocial behaviour. In other words, according to the questionnaire, they were more likely to share, cooperate and pay attention to others. This link is not very surprising: running, climbing, playing tag or ball games are often activities done with others. They offer countless chances to learn to wait your turn, agree on the rules of the game and make friends.

3. An unexpected result for processing speed

Not all the links went in the expected direction. More active children scored, on average, slightly lower on the processing speed index, which measures how quickly a child can complete simple visual tasks on paper, such as spotting or matching pictures. Each additional hour of recorded activity was linked to a drop of about 2.4 points on a scale where the average is 100 and the standard deviation is 15.

We should not conclude that moving “slows down” the brain! This isolated result was not seen for the other cognitive areas measured. Several explanations are possible, and the study cannot tell which one is right: for example, differences in temperament, or in interest in quiet paper-based activities, between very active children and others. It is a good reminder that, in science, a single study often raises as many questions as it answers.

4. Children who had a brain injury move less

Finally, the study identified a group of children more likely to be less active. Children who had a significant brain injury during the newborn period (in the first weeks of life) did less moderate-to-vigorous physical activity, the kind that speeds up the heart and makes you a little out of breath. They also did less free, unstructured play at 4 to 5 years of age.

This finding is important for professionals: these children could benefit from special support to find ways of moving that suit them and that they enjoy.

Correlation is not causation

Before drawing conclusions, a word of caution. This is a cohort study, meaning a study that observes children in their everyday lives without asking them to change their habits. This type of study can identify links, but it cannot prove that one factor causes another.

For example, it is possible that moving more improves ball-catching skills. But the opposite is also plausible: a child who feels skilful and comfortable in their body will probably want to move more. The two effects most likely reinforce each other. To show a true cause-and-effect link, researchers would need to run trials in which some children are offered a physical activity program and their progress is compared with that of children who did not receive it.

We should also keep in mind that the study involves a relatively small group of 123 children, all followed in Melbourne. The results will need to be confirmed in other populations, including in Quebec.

Key takeaways for parents and professionals

Despite these limits, this study sends an encouraging message: in children born very preterm, physical activity goes hand in hand with some motor and social skills that are important when starting school. Here are some practical ideas that follow from it:

• Simply get them moving. The Canadian 24-Hour Movement Guidelines recommend that children aged 3 and 4 get at least 180 minutes of physical activity a day, spread throughout the day, including at least 60 minutes of moderate-to-vigorous activity.
• Value free play. Running in the park, climbing, jumping in puddles: unstructured play counts just as much as organized activities, and it is accessible to everyone.
• Play throwing and catching games. Balls of different sizes, beanbags, bowling games: these are simple ways to practise aiming and hand-eye coordination.
• Move together. Group games with siblings, friends or parents also encourage cooperation and social skills.
• Pay special attention to more vulnerable children. Children who had a brain injury at birth may need adapted support, for example from a physiotherapist or an occupational therapist, to find joy in moving.
• Monitor development. For children born very preterm, regular follow-up of motor, cognitive and social-emotional development until school age makes it possible to spot difficulties early and act quickly.

In conclusion

Let’s go back to Leo, who is still running around the yard. This study does not show that every minute spent running will make him a better ball player or a better friend. But it suggests that, for children like him, moving goes hand in hand with valuable motor and social skills. Above all, it reminds us to pay special attention to children who move less, especially those whose brain was made more fragile at birth.

Encouraging everyday movement through play, fun and discovery remains one of the simplest and most accessible ways to support the development of all children, whether they were born at full term or not.

Study reference

FitzGerald, T. L., Cameron, K. L., Albesher, R. A., Mentiplay, B. F., Mainzer, R. M., Burnett, A. C., Treyvaud, K., Clark, R. A., Anderson, P. J., Cheong, J. L. Y., Doyle, L. W., & Spittle, A. J. (2024). Associations between physical activity and development in preschool-aged children born <30 weeks’ gestation: a cohort study. Archives of Disease in Childhood – Fetal and Neonatal Edition, 109(6), 602–608. https://doi.org/10.1136/archdischild-2023-326045

To learn more: Canadian Society for Exercise Physiology, Canadian 24-Hour Movement Guidelines for the Early Years (0–4 years), csepguidelines.ca.

Note: this plain-language article is based on the published abstract of the study (PubMed, PMID 38408793). The figures quoted come from this abstract.