A device that makes it harder to breathe could help over-50s exercise for longer. Many people in middle age or older find it hard to comply with the persistent barrage of advice to get healthier by upping their physical activity. Now researchers in the US have found that inspiratory muscle strength training can make it easier for them to keep fit. IMST involves inhaling through a handheld device that increases resistance to the breath. After using it to take 30 breaths a day for six weeks a group of over-50s showed a 12% improvement in the time they spent on a treadmill without becoming exhausted.