Elite athletes, including British Olympic heptathlon gold medallist Jessica Ennis, are wasting their time by plunging into icy water after intense exercise and may even be putting their health at risk, according to new research.

Scientists at the University of Portsmouth have found cold water immersion is no more and no less effective in helping an athlete recover after sport than light cool-down exercise.

They also warn the practice of plunging into ice baths, common among elite athletes might do more harm than good.

Lead author Jo Corbett said: “Ice baths are frequently used by sportsmen and women to help them recover after exercise but our results show they don’t work.

“They also pose a number of potentially serious health risks. If people using ice baths are receiving no real benefit then they should probably be advised to stop using them.”