Drink Composition: The “Sweet” Science
Drink a toast to Canada Day! So we’ve convinced you to drink like that cartoon character lost in the desert for days who suddenly stumbles across an oasis, but just what should you be chugging? In our second instalment on hydration (read Hydration Part I here), we take a look at what should be your bottle rocket in the heat of summer…
The Birth of a Monster
What a monster Gatorade spawned. Not a month goes by without yet another magic potion in a bottle appearing on the shelf, each promising to be the perfect carbohydrate and electrolyte drink for athletic performance. Unfortunately, sports drinks have spread beyond targeting athletes and have reached the point where they’re just another name for soda pop. The surest sign of this marketing bunkum is when you see vending machines full of the stuff lined up against the wall at the local Wal-Mart. Now shopaholics may disagree with me, but since when is racing for the blue-light special considered an athletic event?
And the Winner Is…
Forget the hype. Time to unveil the magic foolproof answer to just what you should be putting in your bottle!
Wait, you weren’t actually expecting absolute answers carved in stone, were you? My students will roll their eyes, but my favourite answer to this and every question is “it depends” (closely followed by “what do you think the answer is?”). During riding, the ideal drink composition is infinitely variable depending on the temperature, exercise intensity, and personal preference. Therefore, it is up to each of you to try out different drinks in different situations and see what works best for you! However, here are some considerations and rules of thumb that have passed the test of science as opposed to marketing:
• In addition to getting water into your system, the overall goal is to get about 40-60 g of carbohydrates into your body each hour during exercise. For reference, 60 g of carbohydrates works out to about one large water bottle of Gatorade. This is a case where more is not necessarily better, as your body can’t seem to absorb more than 60 g per hour, and cramming more carbohydrates in may just simply cause gastric distress (fancy term for tummy troubles). Don’t get too hung up on what kind of carbohydrates, though fructose (common in apple juice) seems to take longer to absorb than other types.
• The biggest things you can personally alter are the sweetness of your drink and also the rate at which you drink it. Generally, the “sweet spot” at which the fluid enters your bloodstream fastest is with a carbohydrate concentration of ~2-8% (for reference, Coke is about 10% and Gatorade about 6%). If it’s a hot day, you’ll generally have a decreased tolerance for sweetness, so dilute your drink. Don’t worry that you won’t be getting enough carbohydrates, as you’ll very likely be drinking more fluid.
• Unless you’re into ultra-endurance events, you won’t lose enough electrolytes (salts and minerals) in your sweat during exercise, and what you do lose you will easily replace with a balanced diet. However, electrolytes do tend to improve taste and also helps improve absorption of carbohydrates, so it’s generally a good idea to include moderate amounts of electrolytes (mainly sodium) in your drink (Coke has almost none and Gatorade has a moderate amount). Most sport drinks will have the appropriate ballpark amount already.
• A recent study has shown that carbohydrate drinks are beneficial even in a 40 k TT, an event which takes < 60 min for good roulers (and me every night before I wake up!). The reason for this is not clear, as too little carbohydrate may have actually passed through the digestive system and into the bloodstream to fuel the muscles significantly. However, as the brain generally runs only on carbohydrates, there may be some mental stimulation involved.
Stephen Shoots Himself in the Foot
All the sport drink companies will hate me for this and I’m kissing off any chances they’ll fund my research, but they’re all pretty much the same in terms of composition with minor exceptions. At the end of the day, the best sports drink is the one that you like and will drink a lot without causing tummy troubles. Simple as that, really. Therefore, try out the different ones and go for the one that tastes best to you! And as I mentioned in Part I, set your watch and drink at regular intervals!!!
I can literally write about hydration issues forever (after all, I did nothing but that for four years of my Ph.D.!). For the best sport nutrition and hydration site on the web, nothing beats the Gatorade Sport Science Institute. It’s sponsored by Gatorade, but it’s a completely independent organization that funds a lot of solid scientific research. Another great site for information on all matters about sports science and medicine is the American College of Sports Medicine. Check them out and fire any questions my way!
Now drink up and go impress your co-workers at the water-cooler!
Stephen Cheung is an Associate Professor of Kinesiology at Dalhousie University in Halifax, Nova Scotia, Canada, with a research specialty in the effects of thermal stress on human physiology and performance. He has been an avid roadie since beginning university in the mid-eighties, and still has non-indexed downtube shifters on his winter bike and wool jerseys hanging in his closet. He can be reached for advice or comments at [email protected]