Putting athletes to the test in many different ways, Hyrox was launched in Germany just eight years ago has echoes of recreational marathon running. 

162 out of 520 candidates did not pass the fitness test last year.

One woman said: ‘My cardiologist said to me the difference between me and my dad is that I’m still physically fit.’

The pop icon says she can’t wait to get back on stage for the group’s reunion tour