Sweet Victory

A well-timed dose of sugar can help you run better

Posted: 12 June 2003
by Ed Eyestone

As it turned out, father knew best...

When I trained at the track in secondary school, my dad considered it his duty to make sure I never trained or raced on an empty fuel tank. One of his favourite pre-race traditions was to have me gulp a tablespoon of honey minutes before the starting gun fired. And it worked well for me, even if my tongue was perpetually stuck to the roof of my mouth. Later, at university, my physiology textbooks suggested that eating a simple sugar like honey just before competition might actually have a negative impact on performance. So who’s right? As it turns out, father knows best.

After you eat a simple carbohydrate such as glucose (a sugar often found in sports drinks and gels), your blood-sugar level rises.

This causes your pancreas to release insulin. Insulin’s main function is to reduce your blood-sugar level by helping to transport glucose to your muscles. This is all good because we need glucose to fuel the muscle contractions involved in running. However, our working muscles need to continue to get energy from the glucose in our blood. So it’s important to keep our blood-sugar level from dropping while we run.

But how can you use the sugar in sports drinks and gels to help you perform your best? Like many things in life, it’s all in the timing. As you get closer to race time, you need to pay more attention to your sugar intake.

So, two to four hours before your race, have a light meal (400-800kcal) that is high in carbohydrates and low in fat and fibre. Then follow the guidelines below so you can perfectly time your sugar fix.

One hour pre-race
Taking in the sugar from a sports drink or gel during this window of time is fine for most of us, especially if you skipped your pre-race meal. But there are some people who experience large dips in their blood-sugar levels shortly after eating something sugary.

The result is that their muscles can no longer draw energy from the sugar in their blood. And when this happens, muscle and liver glycogen levels are likely to become depleted more quickly as well. So if you’re prone to these dips in blood sugar, stick with plain water and hold off on the sugar during this time.

Five minutes pre-race
Eating sugar immediately before competition does not result in a dramatic drop in blood sugar. Insulin simply does not have enough time to rush the sugar out of the blood and into the muscles before the race begins. So go ahead and pop a gel or down some honey before toeing the line.

While racing
Depending on the length of your race, sugar can definitely have a positive impact on your performance. During a 5K or 10K, you’ll do fine without the sugar since you’ll probably be exercising for less than an hour. Studies show that during these shorter events, sugar offers little benefit, although it’s not going to hurt your performance either.

During a half-marathon or a marathon, however, sugar gets a big thumbs up. A gel immediately before the start and one every 45 minutes to an hour thereafter have proven effective in boosting performance during endurance events. Take your gel just before a water stop so you can drink some water soon after to aid its absorption and to keep you well-hydrated (as gels alone will not do this).

Just remember that gels and sports drinks don’t replace training. Take them in moderation. With gels, you don’t need a rucksack full of them at the start line unless you plan on selling them for a profit at mile 20 (not a bad idea). And as with all things, try them on your long runs before you use them in an important race.

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Discuss this article

i take glucose mixed with water when i am training cos i heard they were trying to legalise it in boxing between rounds at one time thought it may have a beneficial efect on me not dehydrating etc during and before and after????? or can it have a negative effect ??? i mix it with natural water and drink it before during and after
Posted: 23/06/2003 at 15:58

Glycerine is a good one for hot weather races just don't mix it with any of that Nitro energy drink lol.
Posted: 23/06/2003 at 16:26

Obviously, the author is not a devotee of Atkins who advocates a high fat low carb regime, dismisses carbo loading and cites evidence for a high fat diet improving edurance. Has Atkins any relevance for distance runners?
Posted: 07/07/2003 at 19:42

Glucose is a great fix for short periods of time, Jjsa. it is quickly absorbed and used by the body (hence would be good for the short bouts of energy needed for boxing.) Runners need something that will last a bit longer, but glucose is good for a quick lift, say if you are towards the end of a long run and beginning to go wobbly - crunch up a glucose tablet and wash it down with water and it will give you just a bit more energy.

Ref, the atkins diet - it's just too faddy to be any good for an endurance runner - we need lots of food without the fuss of what is in it!!
Posted: 07/07/2003 at 20:09

Colin, I would not imagine that there is any research done as yet on Adkin's Diet and distance running, or indeed any running at all. There has, however, been research done on High and Low Glycaemic Foods and their relation to high performance exercise. This was done in Australia, quite a few years ago. However, it was/is regarded in the UK as being faddy.
Posted: 13/07/2003 at 09:39

I munch jelly babies on a long run. Not sure if they help the running, but they do taste nice.

Posted: 21/12/2003 at 23:20

I did Atkins for 2 months, mostly the induction faze with very little carbs, and trained throughout at 6-10k. Since moving to a more balanced diet I can't say I've noticed any significant difference.

I'm not clear on how different running early in the morning on an empty stomach is that different to running on a low carb diet. Unless you have enough carbs to tide you over from the prvious evening, you'll be running on fat reserves anyway won't you?
Posted: 31/05/2004 at 08:03

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