Marathon training is hard. This is something I realise as soon as I start training for one of these things and then immediately forget as soon as I cross the finish line.

On Saturday I spent the morning giving a talk to a group of 60 runners taking on the London Marathon for Breast Cancer Care and the Prostate Cancer UK. Some of the runners already had a marathon (or 22 in one woman’s case) under their belt but the majority were marathon virgins.

They listened attentively, laughed convincingly at a few of my jokes and asked questions. Without exception, the questions were about the big day itself – what to eat, what to drink, what to wear. The day itself is no different to training runs – there’s just a big clock at the point where you stop and a load of people clapping as you run past. What you do on race day should be no different from what you do in training – apart from carrying on for another six miles or so.

Training runs are about more than getting the strength and stamina in your legs ready for race day, they’re a time when you work out what works best for you in terms of eating, drinking, clothing, pacing and motivating yourself to go that little bit further. To experiment, to get things wrong and to make the mistakes that you won’t then make on the big day.

This year I’m following the FIRST training plan. It works on the principle of doing just three runs a week but running them faster than a standard training programme would ask you to. I run speed intervals, a tempo run and a long run at race pace every week plus cross training.

Ever time I look down at the training plan before a session I think to myself ‘There’s no way I’ll be able to do that’. And then I usually do it. Each run ticked off the plan is a huge confidence boost – not just in getting the miles done and getting another run closer to the marathon, but in making me believe that my lofty goal of 3 hours 40 minutes might not be that improbable after all.

Training is the hard bit. We know that if you can make it to the start line of a marathon we’ve got a 97% chance of completing the thing. But we focus a lot more on the 26.2 miles at the end of training than the hundreds we clock up on the way there.

Have confidence in the training miles – they’re making you stronger, fitter, and more prepared for your race than you give them credit for. You might struggle with marathon pace today because you’re not ready to run your marathon today – which is lucky because it’s not a for another few weeks. Give it time, trust your training, take risks, make mistakes and try to have fun.