I am currently doing couch to 5k but only once a week. On the days I dont run I do interval aerobics and swim once a week. I have recently increased the amount of exercise I do and only have one day off a week Over the last couple of weeks I seem to have what I would describe as nervous energy and have had a couple of anxiety attacks at night. Someone mentioned I could be producing too much adrenaline which is could be causing this. I thought exercise was good for the mind and health!!! Does anyone have any ideas in this??