Andrew Hamilton looks at optimum fueling strategies for a half marathon, and explains why one size doesn’t fit all MORE
Endurance running and ‘energy gels’
The slippery problem of taking in sustenance when you’re on the move.
‘Energy gels’ – concentrated, syrupy carbohydrate in a tube – are becoming increasingly popular with endurance athletes, many of whom believe that the gels can provide a surge of energy during prolonged races difficult workouts. Can energy gels really enhance performance?
In past issues of Peak Performance, we’ve said some pretty harsh things about the gels, mainly because athletes have been slipping them into their digestive systems without paying much attention to how much water is also going into their gullets.
As a result, they often end up with their bellies filled with either a thick gelatinous syrup (if they’re stingy with the water) or a too-thin broth (if they’re liberal with it). The former can actually drag intracellular water into the stomach, in effect increasing the risk of dehydration; the latter – a stomach mixture with too much water and too little carbohydrate – can lower the rate at which carbos are delivered to the muscles. It seems safer to simply use sports drinks, which are specially formulated to have the right balance of H2O and carbs. So, why write about gels again?
Well, there is no escaping the fact that using sports drinks during a competitive event is not always a trouble-free process, either. For one thing, sports drinks are not always available when you need them (the sports-drink ‘stations’ may be too far apart). For another, the volunteers who mix sports-drink powder with water on the day of the race sometimes experience problems with basic mathematics – and make their concoctions too rich or too weak.
Unfortunately, there’s no way to get around these difficulties by carrying your own sports drink along with you: The stuff is just too heavy! A mere pint of the stuff tucked into a waist belt can harm economy by almost 1 per cent in an average female runner, adding about two minutes to average marathon finishing time, for example.
So how could energy gels help? Take PowerGel, for example. Each little tubelet of the stuff is light as a feather (well, nearly so; the actual weight is about an ounce), and it contains 28 grams of carbs. That means that if you consumed a packet of PowerGel with 400 ml (about 13.5 ounces) of water, you would end up with a pretty good, 7-per cent sports drink in your stomach.
Of course, 13.5 ounces of H2O is a bit much for one water stop, unless you’d like to linger awhile and talk to the volunteers (or help them mix up some Gatorade), but a half-packet of PowerGel and 6.75 ounces of water (about six regular swallows) – consumed together – also produce that very nice 7-per cent sports drink and are not that difficult to get down during one fairly brief pit stop.
In fact, for many marathon runners that specific combination – a half-packet of PowerGel and 6.75 ounces of water – is what should be taken in after every second mile during the race. At an eight-minute marathon pace, for example, such consumption would produce an intake rate of about 25 ounces of water per hour and 52.5 grams of carbos hourly, which is pretty good. At seven-minute pace, a runner would enjoy 29 ounces of water and 60 grams of carbohydrate per hour.
If you’re a five-minute per mile marathoner, the strategy changes a bit. You’d still chase one-half packet of PowerGel with 6.75 ounces of water, but you’d pour that combo into your digestive system every three miles, instead of two. If you’re a 10-minute per mile marathon ambler, your best bet would be to alternate between one- and two-mile intervals. For example, you’d take 6.75 ounces of water and one-half tube of PowerGel after one mile, again after three miles, after four miles, after six miles, and so on.. The result would be 27 ounces of H2O and 56 grams of carbos each hour (for endurance athletes engaged in events lasting longer than an hour, the general rule is to take in at least 40 grams of carbohydrate and 20 to 24 ounces of water each hour).
Stuck on some problems?
There are only two ‘sticky’ points in this gel-water equation: (1) it can be difficult to measure out one-half packet of PowerGel accurately, and (2) it’s also hard to be sure you’re taking in exactly 6.75 ounces of water.
As mentioned, you can’t solve the first problem by taking in the whole packet of gel along with 13.5 ounces of water at one time. That would simply be too much to add to your stomach. A key concern is that if you squeeze three-quarters of the gel into your mouth, instead of merely half, and then top if off with 6.75 ounces of water, you’ll end up with about a 10.5-per cent carbo concoction, which is much too concentrated. So, you’ll have to be pretty adept at parceling out a half-packet of gel.
The second dilemma – figuring out what 6.75 ounces of water is like – isn’t so bad. 6.75 ounces is about six to seven normal swallows of water. It’s just a little over three-quarters of a cup of water, so you could fool around in your kitchen a bit, practising taking in that amount to see what it feels like (don’t forget to jog in place as you do so). During a race (and also during your longish workouts), you’d simply drink what feels like the same quantity every 15 minutes or so.
What about mixing things up a bit – taking sports drink sometimes and the gel-water combo at various other points in a race? It should be fine to drink about 10 ounces of Gatorade or some other sports drink 10 minutes before the start of the marathon and then shift over to gel-plus-water during the competition; mixing the two different things shouldn’t hurt absorption rates. Likewise, during the race it’s okay to take water-plus-gel at one point and then sports drink at another; the sports drink won’t interfere with the water-gel, and vice-versa.
We still think it’s best to use pure sports drink, because you won’t have to worry about measuring out a half-packet of gel accurately, and because an accurately mixed sports drink will have exactly the right sodium concentration (a small amount of sodium helps speed water and sugar absorption). However, if you have concerns about the way the sports drink is concocted or find that you won’t have access to sports drinks every 15 minutes or so (usually because a race doesn’t have enough stations), then the gel-water combo will work. Of course, don’t ever take plain water at one stop and then sports drink or water-gel at another; the plain water will linger in your stomach long enough to dilute the sports drink and/or water-gel which follow – and thus lower carbohydrate absorption. In addition, never wash down gel with a sports drink instead of water; if you do, you’ll end up with a ‘molasses stomach’ (gel must always be swallowed with the right amount of plain water).
Confused? Just remember that you should always wash gel down with THE RIGHT AMOUNT of water (not sports drink). If you use water-plus-gel at one point in a race, you can use sports drink at another point, and vice-versa. A key practice to avoid – from an optimal carbohydrate-delivery standpoint – is dropping plain water into a stomach which contains either gel-water or sports drink.
More gooey stuff
Other brands of energy gel contain different amounts of carbohydrate, so what should you do if you don’t like or can’t find PowerGel?
The key point to remember is that you need about 3.4 ounces of water for every seven grams of carbohydrate you take in during events lasting longer than an hour. That means that if you’ve bought some ‘Chocolate Outrage’ or ‘Vanilla Bean’ GU, for example (research has yet to determine which flavour is better for performance), a little calculation will quickly tell you how much H2O you should sip along with it. Here’s how to do the reckoning: Each packet of GU contains 20 grams of carbs. Since 20 grams divided by 7 grams is about 3, you need 3 x 3.4 ounces = approximately 10 ounces of water with each GU parcel.
10 ounces is far too much to take in all at once while you’re on the fly, but you can cut that in half (to five ounces), squeeze a half-pouchlet of GU into your mouth along with the five ounces of H2O, and be in pretty good shape, although you wouldn’t be getting quite as much fluid and carbos as you would with PowerGel.
At a 7:30 per mile running pace, you would be taking in 40 grams of carbohydrate and 20 ounces of water per hour with the GU-water mixture, provided you were taking the stuff in every second mile. 40 grams of carbohydrate should be enough to be helpful, but the 20-ounce per hour rate of water consumption is borderline.
Interestingly enough, ‘Chocolate Outrage’ GU also contains fat, which has no value at all as far as performance is concerned. Your own body contains all the fat you need for fuel during a prolonged event like the marathon; there’s no need to add it to your body during the race.
In fact, GU and many of the other energy gels contain vitamins, minerals, caffeine, herbal preparations, and a variety of other substances which often look appealing to athletes. Bear in mind that all of these additives are placed in the gels for marketing purposes or because of a misguided understanding of sports nutrition; they won’t improve your performances. There is absolutely no reason to have vitamin E in an energy gel, for example; of course vitamin E IS important in human nutrition, but an acute dose of it taken during the marathon won’t help speed you toward the finish line. The only things you really need during the race are easily absorbed carbohydrate, water, and a little sodium to enhance absorption.
After the race is over, there’s no need to continue taking in sports drink – or gel and water. To boost your energy post-race and get the process of recovery off to a rapid start, take in solid foods – whatever is palatable to you. The usual fare of bananas, bagels, yoghurt, etc. is fine, but do remember to drink water steadily as you eat. Keep drinking until your urine is as clear as a mirror.
Sometimes marathoners ask whether they should start taking in sports drink (or water-gel) after just one mile of the race – or wait until two miles have passed. Well, since you will have swilled 10 ounces of sports beverage 10 minutes before the race begins (that’s the optimal pattern), you can often wait until the two-mile mark to begin drinking. The only exception would be if you complete the marathon at a fairly moderate pace. For example, if you average 10 minutes per mile, you might as well tank up after the first mile, since it will already have been 20 minutes since your last ‘fueling’. Never wait until the four- or five-mile marks to begin imbibing: remember that for purposes of promoting performance and preventing dehydration, sports drinks become steadily less important as the race proceeds. Your most important tipple is the one 10 minutes before the race, the second most important is the first drink you take during the race, the third most important is the second within-race drink, and so on.