LONDON, Sept. 2 (UPI) -- A large, decades-long study suggests birth weight may indicate the level of physical activity a person engages in later in life, according to researchers in England.
Children born weighing less than 5.5 pounds are likely to be rated below-average at sports by age 13 and less likely to take part in exercise or sports through their entire adulthood, according to a study of people followed by researchers since 1946.
The Medical Research Council's National Survey of Health and Development has been following more than 5,300 men and women born in England, Scotland and Wales in March 1946, tracking health and social circumstances of participants from birth throughout most of their lifetimes, offering a large window into lifelong health.
A review of four previous studies in 2011 by researchers at the Institute of Metabolic Science suggested birth weight could be linked to lack of sports ability by age 13, researchers in the new study say theirs is the first to show that this effect continues throughout life.
"The finding that low birth weight was related to less exercise in later life was not explained by socioeconomic circumstances and school sporting ability, both of which are known to be associated with exercise in adulthood," Rebecca Hardy, a professor and program leader at the MRC, said in a press release. "This means that other developmental and social processes are also likely to be involved."
For the study, published in the journal of Medicine and Science in Sports and Exercise, researchers analyzed relevant data for 2,739 participants in the NSHD, finding those born weighing less than 5.5 pounds were 78 percent less likely to be rated above average or average at school sports by age 13.
Additionally, those born heavier than 5.5 pounds were 52 percent more likely to participate in leisure-time physical activities at any point between age 36 and 68. The association between birth weight and activity did not differ as participants got older, researchers reported.
The researchers say future studies will focus on identifying the underlying development and social processes of low birth weight infants across life in order to find ways of helping them get more involved in healthy physical activity.
"We know that regular exercise provides many health benefits including a longer life so it's important that parents, teachers and doctors recognize that those born with a low birth weight might require more support than others in order to achieve sustained physical activity throughout their lives," said Dr. Ahmed Elhakeem, a researcher in the MRC's Unit for Lifelong Health and Aging and lead author of the study.