After Boris Johnson called for the reinstatement  of the two-hours-a-week school sports target (indeed, he suggested that children do two hours of sport a day), David Cameron has again taken to the airwaves to defend  its abolition. This time, he complained that "a lot of schools were meeting that [the target] by doing things like Indian dance or whatever, that you and I probably wouldn't think of as sport, so there's a danger of thinking all you need is money and a target."
But this Daily Mail-style argument from anecdote (does Cameron actually know of any schools that teach Indian dance? And what if they did? For the sport averse, dance is an excellent form of exercise) is unsupported by evidence. As Philip Collins notes in his typically excellent Times column  (£):
The school sport survey, carried out by the Department for Education, shows that in 2009-10 nine out of ten children were doing at least two hours of sport a week. The vast majority of this activity was competitive. Half of all pupils played for their school against another school. Of course, the more competitive that sport truly is, the more it excludes people who are no good. The objective that sport should be competitive cuts across the objective that all should join in. But, in any case, for the slower, weaker and lower, 99 per cent of all schools had a sports day.
In other words, there is no evidence that the two-hours-a-week target was having unintended consequences. To the contrary, it ensured that the majority of children enjoyed a reasonable level of activity. As so often, Cameron's decision to scrap the target was not based on evidence but ideological prejudice.