Originally Posted by sjvcycler
There is no proof that having malto while cycling helps performance. There is evidence that raising your GI before exercise helps, but none that supports having a high GI during exercise has any benefit. I also stick with tap water on rides shorter than 60 miles. For me, all the excess sugar turns to fat because I don't burn enough of it during the ride. If you are going to ride hard just eat correctly before and after. We are not all pro cyclists that need to eat every 15 minutes of riding, keep that in mind.
Those interested in exercise metabolism look at consumption of low vs. high GI foods before exercise to see if there is any effect on performance. The data from recent studies suggest that consumption of lower GI foods 30-60 minutes prior to exercise has the following effects:
The idea is that these effects may enhance performance by perhaps prolonging the onset of fatigue during endurance exercise. Enhanced performance, however, has not been proven in these studies. The GI of carbohydrate is not as important during exercise because the insulin response is blunted during exercise. After exercise, it is actually beneficial to consume high GI foods to enhance muscle glycogen resynthesis, which relies on the presence of insulin.
- minimizes the hypoglycemia which occurs at the beginning of exercise
- increases the concentration of fatty acids in the blood
- increases fat oxidation thereby reducing reliance on carbohydrate as fuel
TLDR Version: 30-60 minutes before consume low GI foods. During, if you are hungry eat. After eat high GI foods to replenish (Choco Milk etc)
Uh, I guess I beg to differ.
Better yet, don't eat anything 30-60 minutes prior to exercise. That's why people have a blood sugar drop to start with. If they'd not do that, they'd not see that effect. Funny thing about studies by folks who don't know their subject. And of course you're going to see more fat oxidation if you don't have blood sugar to burn. You'll also see reduced performance. If you're going to do a long, hard ride, don't eat for 3 hours before - you'll go into steady-state as soon as you start eating high GI right from the start.
Max sustainable intake is about 250 cal/hr. If you aren't burning 250 calories or more per hour, then you don't need to eat that much. However many cyclists burn much more than that.
Looking at my records, I have a 400k ride during which my software said I burned 10,000 calories. Those are usually a little high, but this route climbed over 12,000 feet and I averaged about 16 mph saddle time, 13.5 mph ET. So 40 cal/mile, and therefore about 540-640 cal/hr may not be too far off. I ate 3000 calories of my malto mix and probably another 1000 calories of sandwiches and bars. If I eat about half my burn, I usually don't bonk. Less and I do. So I really try for that 250 cal./hr. on a long ride, say anything over 3 hours. I was a little short on this ride, but not too bad. I'm no speedster, just an ordinary guy who's figured out how to ride. Of course one can eat less on a shorter ride and make up the lost glycogen in later meals. You're going to replace the calories sometime, though. Better to eat them on the bike in my view than later when the slightest overconsumption will turn them into fat.
So what is it about malto that helps performance? Three things: it passes faster across the stomach wall than anything else I've ever tried. It has a higher GI than anything else you can put in your stomach. Perhaps most importantly, you can consume vast quantities of it without burning out your mouth. The fast transfer to the bloodstream means you can eat more of it without barfing. The high GI means that you can recover at the tops of climbs. It's really hard to eat on a climb. You don't see many riders doing much of that. So when you hit the top of the climb, you have to eat enough right then to make up for the time you spent climbing and not eating. Whatever you eat has to get into your bloodstream and fuel your muscles so that after a 10 or 20 minute descent you're fueled and ready to go again, up the next climb. Being able to eat it all day, or even for days means being able to stay fueled. One of the commonest complaints I hear from riders is not being able to find anything they can eat at the 250 cal/hr rate all day.
Just because you're not a supremely talented rider doesn't mean you have to ride slowly. You can learn to ride fast. There's just a lot to it. The cool thing about riding for many years is that one gets to try out pretty much every riding and nutritional theory there is. Some work, some don't.