Treadmill - walk or run, C25K?

When I first started I could barely walk for 5 mins at 3.5km/hr so the first thing I did was slowly increase this (by adding a couple minutes a session) until I could manage 30 mins. Obviously if you can walk faster/longer then you may not need this step but I have a joint condition that was made worse by my weight.

Step 2 was to increase my speed and I used the C25K to do that, instead of running intervals I had intervals at 4km/hr. Once I could do the whole "running" segment at 4km/hr I upped speeds so the "walking" intervals were at 4km/hr and "running" at 4.5km/hr and rinsed and repeated until eventually my walking speed was 5km/hr.

At this point I actually starting adding very slow running in the running intervals, I'm talking about 6.5km/hr (I'm only short and that's the speed where I naturally start to change from walking to running. Again once I'd completed the programme I increased the running speed.

18 months from where I started I've just started a half marathon running programme that has me starting back at intervals of 1min run/2min walk and am managing to run at 10km/hr. I'm also run/walking 5k once a week and did a 10k a couple of weeks ago.

^^^

both are great answers. Get to the point where you can walk comfortably for 30 minutes, and then start c25k. Don’t worry about what speed you should be doing the ‘run’ intervals or what anyone else has done, we are all different. The slower the better for the run intervals – it is better to be able to run the intervals and get to the end of the time, than do have to stop because you are out of breath. The coolrunnings original site for c25k has a treadmill version based on continued time, and many treadmills let you set intervals.

I started running with c25k on a treadmill. When I got to the run twenty minutes bit I had to keep repeating it. Don’t worry about repeating weeks, but firstly try slowing down to try and get to the end of the 20 minutes in a running gait. You’ll feel such a feeling of accomplishment when you do it. I gave up on the treadmill when the sun came out, now I’d rather run in the dark and rain than on a treadmill.

Losing weight won’t come from exercise though – for that you need to keep an eye on your calories, but don’t forget to eat back SOME of your exercise calories to help with all that treadmill work!!!

Using a treadmill is an exercise in boredom. If it's not challenging, it's boring. If you find it boring, raise the speed or the incline or change the program or do something more challenging.