It is common sense that children who walk or cycle to school have a lower risk of obesity than those by car. But driving your youngsters to the gates could also cause their academic work to suffer. Researchers found children who were driven to school, or who took public transport, had poorer concentration levels than those who took a more active route such as walking or cycling. The joint study by researchers at two Danish universities found the regular exercise could advance a student up to half a year in their studies. Children who were driven to school, or who took public transport, performed less well in a test measuring concentration levels, than those who had walked or cycled. The results surprised the researchers, as their hypothesis  originally focused on the effects of eating breakfast and lunch on pupils' ability to concentrate. "The exercise one uses to transport oneself to school is reflected in the level of concentration one has about four hours later," Niels Egelund, a co- author of the report said. "The results showed that having breakfast and lunch has an impact, but not very much compared to having exercise." "As a third-grade pupil, if you exercise and bike to school, your ability to concentrate increases to the equivalent of someone half a year further in their studies," he added. In the survey, taken by 19, 527 pupils aged five to 19 years old, participants were asked about their exercise habits and were then given a basic test measuring their concentration. "Most people know the feeling of being refreshed after having exercised, but it is surprising that the effect lasts for so long," Egelund said. Previous research from the university of Montreal has found that exercise helps our brains make better use of oxygen. It may also reduce mental fatigue  and sharpen your thinking in between gym sessions. And last week Swedish researchers said they found that muscular boys will live longer than their weaker friends. And even if they are overweight by the time they get to adulthood, those with stronger muscles tend to live longer. According to the passage, which of the following statements is correct?
Having breakfast and lunch has a greater impact on concentration than having exercise. Children driven to school perform worse in all tests. Having exercise can refresh us but it doesn't last long. Eating breakfast and lunch can affect children's ability to focus.