*thinks back to the dawn of pre-history when I was teenage girl*
Even back in the dim recesses of time when I was a teenage girl, by that time many a girl was giving up exercise, as not enjoyable. This is no new thing. Whilst I was quite fit (years of dance classes and school sports' teams) the *enforced* fitness of school hockey & cross-country running in all weathers, tennis, netball, rounders, athletics, etc., swiftly managed to put most of us off, thus to many pretty much all exercise could be tarred with the same brush of awfulness. Shame really. Add into the mix the current obsession with *celebrity* where female rolemodels are not exactly fit & healthy, but anorexically skinny, so it's much cooler to smoke and not eat as any fule noes that if you're above a size 6, you're a fat slob who doesn't deserve to be acknowleged as a human being. Besides which, once you've starved yourself to a socially suitable size, one doesn't actually have any energy left for exercise... and as any fule noes once more, exercise plays havoc with the carefully applied make-up and ruins the hair...