The marathon offers more time for things to go wrong, and more time to make mistakes. Finishing is the target, but some don’t even make it to the start line. One American runner, as his first marathon loomed, got nervous about whether he was up to the task. He was concerned when he heard that the potential breaking point in a marathon is at 20 miles (32 km). How many people have felt great at 19 miles but found themselves going backwards by 21?

With this on his mind, he ran 26.2 miles around an indoor track to reassure himself he was up to the distance! He did complete, but only in that training run. Two days later he failed to complete the race.

Many runners lose valuable training time because they increased their mileage too quickly. Experts advise an increase in mileage of no more than 10 per cent per week, or that a long run should make up no more than one third of your weekly mileage. But both rules will undoubtedly be broken as runners suddenly go from little mileage to runs well into double figures.

And no-one likes to stop training when they are injured. 'Can’t afford to miss any days training, I’m preparing for a marathon' is the typical response. One or two days off at an early stage of the injury is better than a few weeks out when we make it worse by trying to run through the pain.

Marathon competitors need to ease down their training in the last couple of weeks and it’s important to get this right. Too early, or too much, and the legs will probably feel sluggish. Don’t ease down enough and your legs will feel heavy. Going from high mileage to next to nothing is a shock to the system so it is better to at least keep the legs ‘ticking along’.

Some good standard runners get it wrong sometimes. One 65-minute half marathon runner did 20 hard efforts of 400m, the day before running a half marathon. No wonder he wasn’t at his best the following day.

Running kit is another problem area. 'If I look good I feel good, so I must get new shoes and kit especially for the marathon'. Think again! Don’t wear anything for the first time going into the marathon, and preferably not for any race.

Blisters are an obvious hazard and almost inevitable if you wear new shoes. It is not unknown for even some of the best runners to make novice mistakes, and maybe have to drop out due to blisters caused by new footwear.

‘Runner’s nipple’ can be a discomfort and if grease or Vaseline is not applied they can look a painful sight after completing 26.2 miles. You don’t want your finisher's photo to be on of you crossing the line with your running top covered in blood!

Don’t try anything in racing that you haven’t done in training. If you want to stock up on carbohydrates the night before the marathon, then do so before long training runs. You’re training your whole body, not just the legs; don’t surprise it on the day by doing something different.

You want to reach that start line feeling great, but don’t spoil all those months of hard training by blowing your race in the first five miles. If other runners hold you up, don’t get irritated. If you weave your way through the masses trying not to lose time you will use up extra energy and run quite a bit more than 26.2 miles… and isn’t the marathon far enough already?

Like many seasoned runners, you will make mistakes, but let’s hope you learn from them and go on to achieve your best.