Okay, it's been a long while since i've really exercised...like..2-3 years. Sure, I've had the basic exercise everyone gets (going to and from work etc.) but nothing to really push me, no sports, no jogging, nothing. So I'm getting concerned about my health (feeling much older than I am, I'm 19) and I've started exercising again. Here's the question. After running for maybe only 10 mins I feel TIRED/shaky/nauseous/it sort of hurts to breathe/headache. Are these all normal symptoms after not having exercised for so long or is there potentially something else wrong?