Feature

Mon 19 Jan, 4:00 pm UTC

Health: No guts, no glory

By Nick Morgan

Everyone knows that to perform well you need to train your cardiovascular system, your muscles and your mind. Well it’s just as important – and just as possible – to train your stomach too.

Riding faster, further and fitter means more fuel, but you need to train your stomach to deal with the extra load. For most, riding for longer than an hour requires fluid to stave off dehydration, and carbohydrates to maintain energy levels.

Sports drinks are handy in this regard because they’re designed to accomplish both. The problem is at race pace it’s hard to stomach the amount of sports drink you need, with a sloshing stomach, nausea and taste fatigue a common problem. 

Studies show this is due to the slowing of gastric emptying during high intensity exercise – the process by which food and drink exits the stomach into the small intestine where it can be absorbed into the bloodstream and carried to the muscles to provide energy.

Armed with this knowledge, you need to decide on your priorities. Essentially this boils down to: do you need to take on a lot of fluids, or carbs, or both?

Whichever you choose, you need to do so when gastric emptying is at its worst. That means mimicking race pace, or even faster.

Hydrate

For riders who sweat heavily, hydration is a priority and need to drink enough to ensure a bodyweight reduction of no more than 2% after a ride.

“It’s a good idea to have a large drink straight before exercise as volume in the stomach stimulates gastric emptying,” says Dr Glenn McConell of Melbourne University. “Try 6-8ml/kg immediately before exercise (so you don’t stimulate urination) and then 2-3ml/kg every 15 minutes from then on.”

But, if you’re a light sweater, taking on masses of fluid may actually be a bad thing as it’ll simply provide extra ballast.

“The time lost through a modest level of dehydration may be less than the time taken to constantly reach for a bottle and top up,” says Loughborough University exercise physiologist Dr Susan Shirreffs.

Carbohydrate

In terms of carbs, you need to look at whether you have a tendency to bonk at the end of rides. If so, you’re probably not taking on enough, so try supplementing your sports drink with gels or energy bars.

Of course, working out your ideal plan doesn’t necessarily make things easier. If you’re a heavy sweater and require lots of carbs, you’ll be putting an awful lot into your stomach, which may feel uncomfortable at first. This is where a bit of trial and error comes in.

The sport drink solution

Most sports drinks contain 5-7% carbohydrate and are ‘isotonic’, meaning the drink matches the osmolality of bodily fluids closely allowing for easy absorption. But you may still want to experiment.

A team at Birmingham University found a mixed glucose/fructose drink left cyclists with less of a 'full stomach' than a pure glucose drink. Similarly, at Liverpool John Moores University, a 15% maltodextrin solution improved performance in cyclists compared to a 5% glucose drink without any increase in stomach issues.

Another reason to experiment is taste fatigue. Sports drinks are quite sickly sweet and consuming the same drink all through a long ride causes the taste to stick in the mouth, exacerbating feelings of nausea and making riders reluctant to drink further. “Taking two bottles of identical drink in different flavours is one way to get around it,” says Shirreffs.

“Small, regular sips during sessions faster than race pace will increase your ability to consume and digest the fluids, calories and electrolytes in your drink of choice,” says Dr Misner. 

User Comments

There are 2 comments on this post

Showing 1 - 2 of 2 comments

  • It's strange really. I thought that taking carbs within 20 mins of a race start would enable your body to dump loads of Insulin in your bloodstream and block any absorption of potentially helpful sugars. These sugars would then be routed off to your bladder to prevent the body becoming Hyperglycaemic.

    I guess the only way would be drinking like a nutter as the race heads off. If your in a short Criterium race then you'd be off the back with a bottle in your mouth. Tricky enough getting your feet in the pedals let alone guzzling a whole bottle of drink.

  • Jerry I think you have your mechanisms mixed up:

    carbs within 20 mins will stimulate insulin

    this insulin will increase use of carbs by the muscles slightly

    (so 5 mins before or low-cal hydration drinks may be better for some doing steady sessions)

    it will not block absorption of sugars in the gut

    hypoglycaemia is usually rare unless a rider goes very long, has blood sugar regulation issues (normally the very lean types that need to eat every 2hrs) or you have lots of carbs 1hr beforehand and in this case its a brief dip at about 10 to 20 mins

    For crits get it down 10-15 mins before, you're likely to be using a high amount of carbs based on the percentage of effort and bursts of power required - feed when you get th echance and use a higher concentration so you can drink less but get carbs in (e.g. 10-15% solutions tried in chain gang sessions beforehand)

  • 1

Post comment:

You need to login or register to post comments.