Eating up the miles - preparing for a half marathon

With the Bath Half about a month away now, I know many who have been preparing for the event will now be getting their final long runs in now and starting to think about their strategy for the last few days leading up to the race. Important as it is to get your training right, it’s also important to get your nutrition leading up to the race day right, so that you are able to perform at your absolute best on the day.


As with running, race day is the wrong time to be turning your attention to your race day nutrition. Spending some time over these last few weeks of training time thinking about and preparing for the way to best fuel yourself on the day, will most definitely pay off.

Here are a few key tips to help you…

The day before: Carb load

The day before the race you should aim to consume around 10g of carbohydrate per kilo of your bodyweight. So for example if you weigh 65kg you should aim to eat 650g of carbohydrates over the course of that day.

The best foods to go for are those that are low in fibre and served with as little fat as possible. This is because your body will be able to quickly absorb and store the energy from the foods, and get rid of the waste quickly. This means maximum energy for minimum “bulk” to  carry around in your digestive system on the day. This is particularly important for those who find they tend to have tummy issues on race day (see below).

Some examples of good foods to opt for include white toast with jam or honey, dried fruit and jacket potatoes with baked beans.

Before the race: Fuel up

Research suggests that a runner should look to consume between one and four grams of carbohydrates per kilo of bodyweight between one and four hours before the race (Burke et al 2011). So if you weigh 65kg you would look to consume between 65g and 260g. As with the carb loading, the best sources are those that are low in fibre and served with as little fat as possible.

During the race: Top up

A half marathon is a long enough race that it’s a good idea to take on some extra fuel during the race. If you’ve only ever run 5k or 10k races before you’ve probably not thought much about fuelling during the run, so now can be a good time to start thinking about it.

Research suggests that those taking part in an event lasting between two to three hours, as a half marathon will for many, benefit from ingesting 60g of carbohydrate per hour of the race. The best sources to opt for would be those that contain both glucose and fructose, as the body is able to quickly convert these into usable energy (Jeukendrup 2011).  

Good examples of sources to choose include gels like this and drinks like this. High5 energy drinks will be given out on the course this year, so it’s a really good idea to take advantage of them. Even if you don’t want to work out the exact amount you should be consuming whilst on the course, grabbing a bottle and having a few sips would definitely be a good idea.

Nothing new on race day!

It’s a cliche but I’ve learnt the hard way that it’s true. If you plan to take on fuel whilst running on race day, I strongly suggest practising during your training runs. This will help you get used to physically carrying gels or drinks, used to ingesting while running if you’re not used to it, and will also just help you decide which products you get on with best.

Gastric distress

Research and experience proves that many runners experience tummy trouble during an endurance event, formally known as ‘gastric distress’ but colloquially known as ‘runners’ trots’ (Browns & Beckers 1993). It’s for this reason that there’s often a massive queue for the portaloo at the start of Lower Bristol Road.

The main causes of gastric distress are the physical motion of running, not being able to tolerate the carbohydrates and drinks (especially caffeine*) consumed before the race, and a reduced blood flow to the gut, as the blood goes to the parts of the body involved in moving a runner around the course.

If you suffer with this issue the good news is that you can train your body to be able to tolerate higher levels of carbohydrate. Do this during your training runs though, by gradually increasing the amount of carbohydrates you consume prior to a run. If you haven’t had the chance to incorporate this into your training however, it’s especially prudent to opt for fuel sources that are low in fibre and that are served with minimal or low fat. This will mean your body has had the chance to evacuate all the waste left from the foods before your cross start line.

*  There are benefits to consuming caffeine before a race, but caffeine does also have the effect of stimulating the gut. If you would like to see if it benefits your race, you should play around with this in your training runs, and most definitely not on race day.

I hope you find this useful. Enjoy the race. You’ve put all the hard work in over the cold, dark, wet winter months. Race day is your time to show everyone what you’ve achieved and to feel blimmin’ proud of yourself. If you would like further guidance on race nutrition for this or any other event you have coming up, get in touch at, or via the Hilton Health Facebook page

Laura Hilton