I find that I get really bad stitches when running. I've looked for info on stitches, but it seems no one really knows exactly what causes them? If anyone has any info I'd be greatful to hear it. My question is though, would using the cross-trainer be as effective for a cardio workout as running? I tend to do 20mins using sprint intervals of 1min sprint, 1min rest and also 20secs sprint, 10secs rest.