I’ve recently had a time lapse in my training because I was having surgery on my feet. I’m fully recovered now having been unable to train for about 6 months 
I assumed that I wouldn’t be very fit when I came to train again and this true. However I’ve been getting nausea when jogging! I may have been going for about 15 minutes before I have to stop because I’m feeling so ill. Is this something as simple as lack of water? (If so it’s not always remedied by an intake of water) Or is this something to do with being unfit? Maybe I’m pushing too hard?