Gauge your fuel

Eat to run strong and recover during your half marathon training.

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Fuelling up properly during training is important. Run on empty, and you could end up crashing and burning. Neglect to refuel after a long run, and you might not recover in time for your next run. Like so many other aspects of training, there is no one-size-fits-all formula. Discover your own foolproof solution by experimenting with different forms of fuel to see which ones work for you. To help you out, here’s a primer on what, how much, and when to eat before you go, on the road, and after you’re done.

Filling up pre-run

What you eat before you hit the road all depends on when you’re running and what kind of workout you’re planning. For an easy-paced run of 60 minutes or less, going without food or drink probably won’t do you any harm (though make sure you’re well hydrated). But for any run that’s longer or more intense, pre-run fuel is important. Go  out on empty and you’ll fatigue sooner.

For high-intensity workouts, traditional thinking advises having a high-carb meal two to three hours before, or a small high-carb snack or drink 30 minutes before. Check out Have Carbs Had Their Chips? for a less carb-focused fuelling strategy.

If you’re running long (10 miles or more), start fuelling and hydrating the day before. You don’t necessarily need to increase your calories, just make sure that carbs make up the bulk of lunch and dinner. Your body will absorb and store the nutrients, and you’ll be able to rely on those stores during the next day’s run.

The morning of your long run, start fueling two to three hours before you go. Aim for 300kcal for each hour before your run. So if you’re going for a run in one hour, have 300kcal; if you’re going for a run in two hours, have 600kcal.

When should you fill your tank?

Each runner is different, but in general, the bigger the pre-run meal, the more time you’ll need to digest it. After a 200-300kcal meal, you could be ready to hit the road in 30-60 minutes. Any more calories, wait 60-90 minutes before you start your run. So what’s the perfect pre-run snack? Familiar foods that are easy on your system, low in fat and fibre, and high in carbs will boost your energy without upsetting your stomach. Check the panel opposite for some ideas.

Fuelling on the run

If you’re on the road for less than 60 minutes, you can rely on water and/or your body’s own glycogen stores. Any longer, and you begin to deplete those stores, so consuming carbs on the run can make sure you don’t crash and burn. Long runs are a good time for rookie runners to practise balancing food and fluids ready for race day. In fact, coach Jenny Hadfield, co-author of Running for Mortals (£7.99, Rodale), urges many newbies to run a 10K four or five weeks before their half to learn how to manage race-day nutrition. The key is to fuel at regular intervals, and before you actually need it (for example, every half an hour during a long run).

Experiment with different brands and flavours of energy gels and sports drinks (see overleaf for more on what and when to drink), and find out what sits well in your stomach. And try the brand that will be provided at the race (if known). If it doesn’t sit well with you, plan to bring your own on race day.

Eating for recovery

What you do in the half hour following a long run or a hard workout can determine the quality of your next run, says Suzanne Girard Eberle, a sports dietitian and author of Endurance Sports Nutrition (£14.99, Human Kinetics Europe).

The 30-60 minutes after your run is prime time for recovery. That’s when your body is ready to restock glycogen stores and start repairing muscle tissue so you can bounce back for your next run, Eberle says. ‘A lot of runners miss this window, and that’s where they get into trouble,’ she says. ‘It will start taking longer to recover, increase the risk of injury, and it can make training seem harder than it needs to be.’

Refuelling is most important if you’re out for an intense effort – such as an interval session, a tempo run or a long run of 75 minutes or more – which taxes your muscles and drains your muscle glycogen stores.

How many carbs do you need for recovery? Divide your weight in pounds in half and eat that many grams of carbs (so a 120-pound runner would aim for 60g). Aim for a carbs-to-protein ratio of 3:1 (that 120-pound runner would aim for 20g of protein). Don’t stress about hitting the exact ratio though; some experts recommend a higher ratio of protein to carbs. Just make sure you’re getting both. See right for post-run snacks.

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Discuss this article

Why no advice in the 'Fuelling on the run' section. Really hard to guage what is right for you on long runs, I try to take in 160-200 kcal an hour on longer runs, is that good or not? No website seems very clear on this important issue.

Posted: 03/07/2013 at 19:22

This is an interesting argument, and one that still seems to have something missing, even with the latest thinking on carbs not being the 'golden fuel'.

I race 10k-21k and train without using pre or during run carbs. But I have found by trial and error that if I start taking glucose tablets 20min before and then continue them at about every 20mins then my pace is more consistent and faster. I also do not seem to get any '40-min' effect from my glycogen. Whatever I eat the previous day seems irrelevant, and my only rule for breakfast on the day is eat something, but more importantly don't eat too much.

I'm now 57, 1.85m, 70kg, only run offroad, flatish 10k time sub45min, 10k fell ~60min, so not bad for my age.

Does anyone else relate to this ?

Should I actually be fuelling up during my training runs ? (So far I would say that training at 'less than perfection' and then racing at 'fully fuelled' does the trick for me.)

Posted: 03/07/2013 at 19:41

Hi monocep, I've done a few calculations on energy burn and kcal intake, and my 1 glucose tablet every 20 mins seems to balance my typical hill-race requirements.

There are a couple of things to remember: 

Glucose is the only thing that requires no digestion before its available - your blood sugar level is actually your blood glucose level.

It can take 20mins for any other fuel to be metabolised and become available as fuel.

Sugar (sucrose) is only 50% efficient as a quick fuel as it is 50/50 glucose/fructose, and the fructose has to be metabolised and is hence not immediately available as fuel. Therefore you don't get all the hit you think when you eat 'sugars'.

Some of us cannot metabolise Fructose very well and can get stomach pains from too much !

Hope that wasn't too much in one bite

Posted: 03/07/2013 at 19:52

Hi Phil, with you on those stats,

Thanks for the feedback, lots of food for thought, branching out on the longer runs and no advice from RW on any of it, luckily there's forums. 

I know this is a HM thread and sorry for that but even HM training runs can run into the 3rd hour, dont normally fuel on the run under 2hours but like what you're saying, very close really on intake. Might need to scale down my calories, just gotta find what works I suppose,

thanx again, I got quite a bite lol

Posted: 06/07/2013 at 20:42

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