Sportswear is getting a robotic upgrade. A new exosuit, which is worn like a pair of bike shorts, makes both walking and running more energy efficient. Philippe Malcolm at the University of Nebraska Omaha in the US and his colleagues developed the flexible suit, which cuts the energy a wearer uses when walking by 9 per cent and the energy spent on running by 4 per cent. This exosuit isn't the first to cut the energy spent moving – others have been able to make either walking or running alone more energy efficient – but Malcolm and his team say it is the first to aid in both. The device could eventually be used by people who spend a long time on their feet, such as rescue workers, firefighters and military personnel.