Stadium tours and high-energy live shows mean that being a rock star is not what it used to be. Harry Bullmore explores how Harry Styles, Taylor Swift and Tom Grennan have raised the bar of fitness goals which boosts stamina and heart health W hen it comes to today’s musicians, it seems, the debauchery of the “Sex, drugs and rock and roll” lifestyle is a thing of the past. Harry Styles graced the cover of Runner’s World this month, having finished last September’s Berlin marathon in a mightily