10 half marathon training mistakes to avoid

Training for a half marathon is a great experience for any runner. You’ll enjoy a good mix of training sessions, and start to notice a real improvement in both endurance and speed. However, there are a few mistakes you might make along the way that could stall your progress. Avoid these common half marathon training errors, and give yourself the best chance of achieving your full potential on race day.

Choosing the wrong training plan

Some attempts at training for a half marathon can be undermined from the very start by the wrong choice of training plan. 

This is all about the targets you set for yourself. If you aim for a time that isn’t suited to your ability level, the training plan you use will inevitably be wrong as well.

Aiming for an unrealistically fast target time will result in a training plan that is too hard to follow, leading to potential injury and burnout. Similarly, if you’re too conservative with your target time, you’ll most likely find that you get bored of your training and don’t progress as you should.

If you’re taking on your first half marathon, you can work out a rough target half marathon time by taking your 10k PB and multiplying it by 2.25. So if your 10k time is 60 minutes, your target for the half marathon would be 2 hours and 15 minutes.

For those of you doing multiple half marathons, you’ll have a better idea of your abilities. Try to keep target times realistic based on your previous performances. If you have the time to train, an improvement of between three to five per cent is a good target. 

Too much too soon

Having chosen the right training plan, it is very easy to throw yourself into your running with too much enthusiasm. But it’s a long road to train for a half marathon. 

The peak of your training plan should come roughly two weeks out from race day. This is the optimal time to complete your longest run, then gradually taper your mileage in the lead up to the race.

However, many runners get carried away with the excitement of signing up to an event and try to do too much too soon. Peaking three months in advance of the race is no use to anyone, and only serves to increase your risk of injury.

Even though your initial training runs might feel slow and short, you need to respect your training plan and focus on making gradual improvements.

Not respecting injuries

Whether you’re used to running regularly or not, training for 13.1 (21.1km) miles is bound to take its toll on your body. You will get used to aches and pains in various places, but many runners also ignore their body when something really hurts.

Injuries are frustrating for any runner, but they are a natural part of training and you need to respect them. An injury is usually your body’s way of telling you that you need to ease back on the training slightly, and give yourself time to recover.

If you do ignore an injury and try to run through it, you’ll likely find it has a negative compound effect on your overall training. Think of it this way - is it better to miss a couple of sessions to give a niggling injury a chance to heal, or push through those sessions and end up being injured for two months?

If you have persistent pain, there is probably a more serious problem, so go and see a physio and get the issue checked out. They’ll be able to give you the exact steps you need to follow to recover as quickly and safely as possible.

Not warming up properly

This is such an easy mistake to make and it catches so many runners out. The warm up is almost as important as the run itself, and is a key aspect of your training session, especially in colder weather.

It is heart-breaking to miss out on a race after weeks of training because you’ve pulled a hamstring after failing to warm up properly. 

A good warm up should include some dynamic stretches and then some very light jogging. The goal is to increase your heart rate without pushing yourself past low to moderate effort.

Similarly, you should follow up your session with an easy cool down and some light stretches.

Getting it wrong with the long run

Your weekly long run is vital in terms of any endurance event. It helps prepare your body both physically and mentally for the challenge ahead and also represents the developing progress of your plan. 

Doing a long run every week is extremely important, and you should increase your mileage slowly and carefully. 

Some runners ignore the importance of a long run or they make the mistake of increasing their distance too quickly. Aim for an increase in mileage or duration of 10% every week, and you shouldn’t go too far wrong.

Skipping warm up races

As anyone who has ever competed in a half marathon will tell you, warm up races are important, because they can offer you experience in a mass participation environment. 

It is not a great idea to turn up on race day with no idea of what awaits you in terms of water stations, a mass start, toilet facilities etc. The list is endless, but all of these things can be practiced in advance. 

Make sure you enter a couple of 10k races and perhaps a 10 mile race. Those who don’t, often discover they are in for a nasty shock on the big day.

Neglecting refuelling and hydration

It is such a shame to see runners follow a training plan to the letter and then perform disappointingly in the race. This is often because they haven’t eaten properly or followed a sensible hydration strategy. 

Don’t be afraid of eating more food when you’re training for a half marathon. You will burn an extra 100 calories for every mile you run, so you need to eat more carbohydrates during your training. If your body doesn’t have the fuel it needs to perform, then you’re going to have a tough time during your training sessions and on race day itself.

Protein and fruit and vegetables are in, junk food needs to go. And fluid intake must be carefully monitored before, during and after training runs.

A simple rule to follow is to stick to natural, unprocessed foods. Around 65% of each meal should be made up of healthy carbohydrates and fruit/vegetables, with the rest rounded out with protein, and a small amount of healthy fats.

Ignoring interval sessions

For those runners looking to improve their PB or just get around in a respectable time, interval and tempo sessions are vital. 

If you train slowly at the same pace on all of your runs, you will run slowly during your half marathon. If you try to increase your speed on the day you might find you have no change of gear available to you, apart from possibly even slower! 

Most training plans will suggest interval sessions with different speed work and tempo runs. Ignore them at your peril.

Not enough rest days

Rest and recuperation can be just as important as running itself. It is always tempting to want to do more, but you mustn’t, or your body will start to fall apart. 

Follow the plan and make sure you rest on the days your plan tells you to. Those who don’t, quickly find they can’t actually do anything because of injury.

Ignoring the taper

We all lead busy lives and sometimes we have to cram things in at the last minute. 

But while you may be okay with some last minute studying for an exam, or a late night session at work to finish a long report, it doesn’t work like that with running. 

Once you get to around two weeks out from race day, there is nothing more that you can do in terms of fitness for a half marathon. This is the point when you should start to reduce your training mileage, and ensure you have plenty of energy in your legs come race day.

If you haven’t done the work, you won’t be able to catch up during the taper. So don’t even try, because all you will do is jeopardise your chances of even starting the race and certainly of finishing it.