Couch to 5k

Firstly, well done and good luck. I did C25K last year and really enjoyed it and have kept running to the point I have just signed up for my first marathon (very scary!).

As for your question, it's very difficult to say as different for everyone. General advice for people starting out is go as slow as you can whilst running with good form (a quick search will give you some advice on form). If it's way too easy then maybe try 4.5 rather than such a big jump?

Overall though, my personal advice is to focus on increasing the time you spend running and not worry about speed for now. If you're finding it too easy then maybe make your last running interval of each run longer rather than increase your speed. If you're finding you're able to do *much* more than prescribed then perhaps skip ahead to the next week in the plan. This is what I did and ended up doing the 9 week plan in 7 weeks. I did my runs outside and although I deliberately tried to keep my runs slow I found I got faster as the weeks went on even without trying.

That's great it went so well. Tempting as it might be, try not to push too hard, too quick as that's surefire route to injury. Given you already walk lots you have a headstart, but your joints & muscles need to get used to the running action even if from an energy/CV fitness point of view you feel you could go longer/harder. If you don't already, get into the habit of stretching and doing some hip/flexibility exercises as well.

That all being said, continue to enjoy it and good luck. I look forward to reading about you doing a non-stop 5k!

On the treadmill, I did 6km/h (4mi/h) for the walk sections and 9km/h (6 mi/h) for the jog sections. I try and stick to that pacing outside.

I started walking at 3 mph and running at 5 mph. When I got to the longer runs, I could not keep the pace up and run the whole time, so I'm down to running at 4 mph. I'm in week 6 now so Friday is a 25 minute run. If I can do that at 4 mph, I'll be happy.