I've bitten the bullet, joined a gym, and now done two weeks of c25k. Today was harder, picked a treadmill away from the air con and nearly fainted, but I'm feeling fitter and looking forward to week three starting on Friday 
Has anyone done this on the treadmill? Am planning some road running when my fitness increases and the weather is better, and have signed up for a sponsored 5k later in the year. But for time being I'm in the gym.
What kind of speeds should I be aiming for? I've been walking at 6.4kph and running at 9.7 which was good (till today when I slowed it down due to heat) but wondering if this is a bit silly at this point and I should be slower? With a cool down etc I'm doing 4k in just over thirty minutes which I'm happy with but not sure if im pushing myself too hard too quick?