Last week I thought I'd take my training a bit easier as I was doing a half marathon at the weekend.Went on the elliptical trainer at the gym. Had slight twinge in an intercostal muscle whilst on machine.Then OK for next 2 days. The day of the race,felt slight twinge again whilst driving to the race;ignored it,felt no pain during the race. Then that evening and for last 3 days suffered excruciating pain on every inspiration,cough, sneeze etc! Now pain is subsiding, very wary of elliptical trainers now!!!