We did the 6-week F45 challenge workout – and the results were life-changing

F45 challenge review: For six weeks, HELLO!’s Hollie Brotherton and Katy Huke took on the tough physical fitness challenge at London’s top gym, loved by David Beckham. Here’s what happened when they did 5 classes a week, stuck to a meal plan and took part in InBody scans F45 challenge review: For six weeks, HELLO!’s Hollie Brotherton and Katy Huke took on the tough physical fitness challenge at London’s top gym, loved by David Beckham. Here’s what happened when they did 5 classes a week, stuck to a meal plan and took part in InBody scans