Workout recording

when I first got my watch it recorded my first few workouts then all of a sudden everytime I press record workout it will go for about 30 seconds to a minuite and become paused then I unpaused it and it goes for another 10-30 seconds and becomes paused again and its just this same thing back and forth so I just end up turning it off everytime as it doesnt work.

Please, how do I get it to work - this was the main feature I bought the watch for and it hasnt been any use.