Last week, Public Health England said 6 million middle-aged adults in England take less than 10 minutes’ brisk exercise a month, risking their health. But when does the problem start? It seems the answer is “very young”. Last year, a damning international study portrayed British children as among the least active in the world. Despite government guidelines for parents to continue encouraging kids to exercise every day, compared with 38 other nations including Venezuela and Slovenia, England and Wales are currently third-worst in the list – with Scotland at the bottom. Only 22% of boys aged 11 to 15 manage the recommended amounts of daily exercise, and just 15% of girls.
But while active childhoods can have many obvious short-term benefits, including reducing the rates of obesity – the latest figures suggest that nearly 20% of 10- to 11-year-olds in England are obese – the little we know of the long-term benefits point towards exercise being even more crucial than we might already assume.
Denmark and Sweden, which have long been interested in the link between childhood physical activity and achievements in later life, have markedly less prevalence of metabolic-related conditions in children. Researchers examined a database containing the fitness records of 1.2 million Swedish men born between 1950 and 1976, on entry into military service at 18. They then traced their subsequent progress through life, and found that cardiovascular fitness appeared to be predictive of cognition in middle age. In other words, the more exercise they had done during adolescence, the more likely they were to be successful professionally.
Neuroscientists believe there are a number of reasons for this. Studies show that doing enough physical activity to improve cardiorespiratory fitness in childhood is directly related to the structure and function of the developing brain, especially regions such as the hippocampus, which is involved in memory, and the prefrontal cortex, which does not complete its formation until your early 20s.
“The developing brain in specific regions appears to be particularly amenable to exercise,” says Charles Hillman, professor at Northeastern University. “The development of the prefrontal cortex is involved in our ability to think, reason and commit purposeful action based on thought and not impulse. In everyday life, it is crucial in our ability to lead successful and healthy lives. Exercise increases metabolic demand and, in response, the brain increases angiogenesis – building more capillary beds to transport blood and oxygen to different regions. It also increases the formation of synapses between neurons, increasing the ability of different parts of the brain to talk to each other.”