My 28 year old daughter was recently at a gym taking part in a boot camp, she was young fit and very slim.
After only 20minutes she collapsed, was sent to hospital and diagnoised with dehydration and sent home.
That night she became increasingly ill and by morning couldnt walk or talk and was driffting in and out of conciousness.
On re-admission a cat scan was performed then an mri.......... she had indeed suffered 2 strokes as a result of a vertabral artery dissection brought on by over excertion.
She is now on the long road to recovery but its a long road..........
So be aware for yourself and others young people do have strokes from even healthy activities.