Over the years I have learnt how to deal with this, sometimes it works, and sometimes it really doesn't. Most of the time it is the inner battle with yourself and you start to make excuses like: "I might slip on the wet leaves, it's probably better I don't go!". Quite possibly I may or may not have said that to myself before!
Make plans to go running with someone
The easiest way to get out the door to go running is to run with someone. If you have arranged to meet your friend, work colleague, or training partner then the chances are you are not going to let them down, and vise versa. It makes backing out the run that much harder, and as we all know once you are out the door half the battle is won. I'm not sure anyone would spend the time getting ready, leave the house only to turn round half way down the street. I hope not anyway!
Mix up your routes
Running the same routes every week can become a factor with motivation as well. You really need to mix it up, vary your routes and get exploring. Granted, you might not like the idea of getting lost on a run and being out for hours, but just running somewhere else can really help. I find the time goes by quicker if I do not know where I am running, or it is somewhere new. Another idea which I’ve seen mentioned is jumping on a train for a few stops and then running back home. It might be an idea to take your phone with you just in case you get really lost.
Have a challenge on the horizon
Setting a goal, such as a race will be a big factor in motivating you to go out the door especially if the race is coming up soon. If you have set the target of a marathon months and months away, then try to find other races in between. You could sign up to do a 5k, 10k or even a half marathon as part of your training or a flat out race. A lot of athletes find local half marathons and do them to get their long run in on a Sunday. This means you are technically not doing your run on your own. Just remember what the purpose is for the race you are doing – is it to get a PB or is it just part of training, in which because you should ensure you don’t get carried away and end up injured.
Join a club
If you are not a member of a running club, then now would be the time to join – this will instantly give you access to more knowledge and a whole host of people to go running with. They will often have set times where club members meet and go running, and once joined you will have no excuses. I am a strong believer in joining people to go running, and once you get into the routine you'll be set.
Set yourself treats along the way during the months of training, maybe a massage after your long run or a new pair of trainers after three months of training. Setting these little rewards will help keep you motivated and also help with your training. When you do a local race it is a good idea to see who finishes around you and maybe find out where they train – chances are it won't be far and you can extend your list of running friends. Again, this will give you even more people to run with and it is great to bounce ideas off people about training.