text: Intermediate 
  
  
  Do you want your child to be good at sport, play for the school team and, maybe one day, even compete in international competitions? Well, try to make sure that your future Olympian or World Cup winner is born in November or October. A study by one of the UKs leading experts on childrens physical activity has found that school pupils born in those months are  tter than everyone else in their class.
  November- and October-born children were  tter, stronger and more powerful than those born in the other ten months of the year, especially those whose birthdays were in April or June. Dr Gavin Sandercock of Essex University and colleagues found that autumn-born children had a clear physical advantage over their classmates.
  The research involved 8,550 boys and girls aged between ten and 16 from 26 state schools in Essex. All were tested between 2007 and 2010 on three different measures of  tness: stamina, handgrip strength and lower-body power. The results revealed that a childs month of birth could make signi cant differences to their levels of cardiovascular  tness, muscle strength and ability to accelerate, all of which predict how good someone is at sport.
  November-born children were the  ttest overall as they had the most stamina and power and were the second strongest. Those born in October were almost as  t, scoring highest for strength and coming third for power, with December children close behind.
  The gap in physical ability between children in the same class but born in different months was sometimes very wide. For example, we found that a boy born in November can run at least 10% faster, jump 12% higher and is 15% more powerful than a child of the same age born in April. This is, potentially, a huge physical advantage, said Sandercock. Such gaps could decide who became a top-level athlete because, as the paper says, selection into elite sports may often depend on very small margins or differences in an individuals physical performance.
  The study, which has been published in the International Journal of Sports Medicine, found that, when scores for the three kinds of  tness were combined, those born in April were the least  t, then those in June. That could see those children excluded from school teams and becoming sporting underachievers, Sandercock said.
  The  ndings seem to show that children born in the early months of the school year enjoy a double autumn advantage  they are already known to have an academic advantage and, now, they also appear to be better equipped for sport, too. The results show that something other than the relative-age effect  the greater maturity of those born early in the school year  is the cause, especially as the  ttest children were not the tallest or heaviest, he added.
  The authors believe that autumn-born childrens greater exposure over the summer months, towards the end of pregnancy, to vitamin D is the most likely explanation. Seasonal differences in vitamin D concentrations in the womb seem most plausible, they say. John Steele, chief executive of the Youth Sport Trust, said the quality of a young persons introduction to sport at school can be a major factor in their sporting development. Children that get a high-quality  rst experience are those that will have greater agility, balance and coordination, and are more likely to develop an enjoyment of physical activity and excel in sport as they grow up, he said.
  UK Sport could not say if a disproportionate majority of the 1,300 athletes across 47 sports it funds were born in November and October. Natalie Dunman, its head of performance, said that while the differences highlighted in the new  ndings were borne out by teenagers competing in junior-level competitions, they had disappeared by the time sportspeople were taking part in adult competitions. She said: With elite, senior athletes, there are many factors that make a champion and our work hasnt uncovered anything to suggest that month of birth is one of the key ingredients.