Treadmill? : Hi ☺ I was just woundering whether... - Couch to 5K

Couch to 5K
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Hi ☺

I was just woundering whether it makes a difference using the treadmill as apposed to going outside, my working hours arnt the best and don't get in until 8pm and have a young daughter and husband isn't always at home to watch our daughter whilst u go out so just using the resources I have!

12 Replies


I used a treadmill for the whole c25k set at a incline of 2% as I also found it hard to fit running outdoors in!

A few weeks ago I started outside and didn't find the transition to hard just did notice I had to stretch a bit more as a bit tougher on the legs.

Tbh I tend to revert back to my treadmill quite a bit as I enjoy watching tv when running :)

Newbie9 in reply to Jamesa87

That's good to know!! I was worried that when I was able to go out that the transition would be difficult, cold air, hard ground and etc thank you for your reply! I havnt been doing stretches or anything though as I didn't realise I was meant to be doing them... Woops!

Jamesa87Graduate in reply to Newbie9

Don't get me wrong it was tougher outside than the treadmill but I think the incline helped.

When I first started I was 18stone and getting very sore legs / back etc. I did have a gait analysis and bought some proper shoes due to my over pronation.

Now 2 stone lighter and fitter I don't get as sore but really do feel it if I don't stretch before and after my run.

Newbie9 in reply to Jamesa87

Awww wow!! Well done you! That's amazing! Thank you I will have a look at doing some stretches too to be on the safe side.


Welcome to the forum.

This guide to the plan is essential reading

Treadmill is fine if you have a high boredom threshold and be prepared to have a few runs to make a successful transition to outdoors.

Enjoy your journey.


Very different running, but many folk use the treadmill. You do what is necessary for you:) Follow the link that IannodaTruffe has given you. Take it slow and steady and well done!


I started outdoors but had to switch to a treadmill due to the cold not agreeing with my asthma. I’m on week six, and once I’ve graduated indoors, been on holiday and got the kids back to school at the end of April, I plan to start the plan from scratch outdoors - hoping for warmer weather by then! Anyway, I digress. I don’t think it makes a difference where you do it, running 5k indoors is still running 5k! As soon as I learned to take the pressure off myself and stopped worrying about what others may think, I started to really enjoy it.


I completed the full c25k on a treadmill, incline of 1.5/2ish every time. I did my very first outdoor run last night as I couldn’t make it to the gym. I’d been making excuses about why I wouldn’t do it all day but it actually was really good. My second consolidation run, faster than any I’ve done on the treadmill- avg page 30-40 seconds faster than usual!- and I felt ok. My only issue was my ears got cold so had a headache when I got back, I’ll need to invest in a headband I think.


Biggest thing in the transition from treadmill to outdoors - the treadmill was lying.

Speed and distance on a treadmill are just random numbers that the treadmill invented. So whilst you were running on the treadmill at an indicated speed of 12kph and covered 6km in your 30 minute run, the numbers are totally fictitious. Did you think that the treadmill worked out your cadence, stride length, time in the air? No. It just did a kind of best guess.

So when you go outside, you're inclination is to run at your treadmill speed (and expect to cover the same distance). This is always far, far too fast.

When you transition outdoors, you have to work out your own pace. Just plan to run very slowly. After the toxic 5 (or 10) minutes are up, you'll find that you have settled into a comfortable outdoors pace. That almost certainly is not the same pace as the treadmill indicated, but it is your natural outdoor pace.

Don't get me wrong - a treadmill is a fantastic piece of kit. If you do all your running on a treadmill, the speed setting can help you compare one run against another, or you know that you run at 10kph and it helps you set the speed each time you get to the gym. It is just that the speed does not resemble real speed (and this catches runners out who transition outdoors).

GranspeedGraduate in reply to MarkyD

Interesting to read this, and it makes intuitive sense to me. I walked on a gym treadmill last year to get some exercise during yucky weather. Found it ultra boring but useful, as I couldn’t cycle in the snow & wind. This winter’s C25k was an alternative, which I could do outside. Better weather this year helped, but outside is key for me. But we are all different!


I’m now on W7R3 and have done all my running on the treadmill. Apart from the bad weather factor, it encourages my husband to go to the gym too. Although he is not doing the C25K it gives us both an incentive to go together. I also wanted to avoid too much impact on my joints as I’m an unfit 61 year old female!

Not sure what I’ll do when I graduate as the programme has been a great personal challenge 👟👟😃


Hey, same here! I move onto W9 this week and have done all my runs on a treadmill so far. I had one gathering dust in the garage and I started in January, and to be honest I think I personally would have given up by now if I had to run in the cold and rain etc as a newbie trying to build the habit, I'd have found excuses not to run. I have accidentally had it on a fairly steep gradient though from the start which I didn't realise, so I have just kept it on because I've been managing with it on (and I don't think I know how to change it ha 😂) and I'm hoping it helps with my transition to outdoors which I plan to do after graduating next week, I'd like to try park runs etc.

As a new runner I think it's been good for me to see what I'm doing, and experiment with different speeds etc, and also track my progress. I know people say to take it with a pinch of salt etc and I do, but I do think it has helped me to build and regulate my speed so far 😊 I think without it in the early days my brisk walk pace would have been a pitiful crawl 😂

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