Hi - I'm now on week 6 of the couch to 5km. I've found the gradual build up very good and am pleased at the way my stamina is improving. However, the podcasts say you should breathe in through your nose and out through your mouth, but when I start running my body just breathes in and out through my mouth. When I made an effort to breathe in through my nose, I panicked and got very breathless. At first i coped alright, but now at week 6, my legs feel like lead and I'm very tired after the run. I'm 56 and pretty unfit, am I trying to do too much?