What Causes Migraines During Sports Activity?

My 23 year old son said his blood pressure was 141 over 88. He has also been experiencing migraines. We made an appointment with our family physician. He played college basketball, and has always worked out. Somewhat less in the last two years. In the last two years he has gained 15 lbs. He is somewhat stressed. This is his first week back in the new semester (nursing). Any advise? BTW He eats typical college diet. He doesn't drink or smoke at all. Any suggestions?