Your experiences with protein - chemist type folks

Triathlon Forum
1

I’ve been messing about with my training and race day energy sources. Instead of using Gatorade or gels, or “real” food, I’ll mix up a 16 ounce bottle of water and a 2 scoops of dextrose and a smaller scoop of protein powder and about a 1/4 of a teaspoon of sea salt. For 3 hours on the bike last week I used 2 bottles and had a pretty consistent energy level for the whole ride (1st half at IM race pace, 2nd half at 1/2 IM race pace). My question is by adding the protein powder to the dextrose am I reducing the gycemic index of the drink? Is this what the folks at Infinite do?

as an aside, the latest Merkin report sez this

Dr. Gabe Mirkin’s Fitness and Health E-Zine
June 6, 2010

Protein After, Not During, Exercise

   High-protein meals eaten immediately after hard exercise

have been shown to help athletes recover faster, but the data that
taking protein during exercise improves an athlete’s performance
is extremely weak.
Researchers from the University of Birmingham, UK, showed
that adding protein (19g/hour) to a sugared drink does not improve
one-hour cycling time trial, maximum power; or post exercise
isometric strength, muscle damage (CPK) or muscle soreness
(Medicine & Science in Sports & Exercise, June 2010). Protein also
does not help athletes cycle faster in a 50-mile time trial
(Medicine and Science in Sports and Exercise, August 2006).
Most studies showing that adding protein to a carbohydrate drink
improves performance were in people working at a fixed rate of
effort over a long time, rather than using spurts of energy as
athletes do in competition.
Just about everyone agrees that taking in a carbohydrate
drink helps improve performances in athletic events lasting more
than an hour. In events lasting more than three hours, you also
need salt. Calories come from carbohydrates, fats, and proteins.
During highly-intense exercise, your muscles use carbohydrates far
more efficiently than proteins or fats. So carbohydrates are the
calorie source of choice during intense exercise.
All sugared drinks except those with added artificial
sweeteners contain eight percent sugar because that is the
concentration at which the drinks taste best. You can increase
endurance equally with fruit juice, special energy drinks or
sugared carbonated soft drinks. Adding caffeine to the drink
increases endurance even more because it helps to preserve your
stored muscle sugar.

2

In short, yes. Adding a protein source to a carbohydrate drink or meal does lower/normalize its glycemic index. Do be careful with it and make sure it’s tolerable on your stomach, though. Historically protein powders give a lot of people GI problems, simply because it takes so much longer to digest. Incidentally, that’s the reason why substituting high-protein for high-CHO meals is consdusive to weight loss; because it’s so much harder for the body to digest. It takes more energy to break it all down, increasing your metabolism and creating what is called a metabolic advantage.

The guys at Infinit do add a tiny bit of protein for that reason, but it’s a VERY small amount. Personally, my Infinit mix is 73:3 CHO:protein.

If you were one of my athletes, I’d suggest sticking to gels, drinks, sports bars and candy bars, depending on how ironclad your stomach is, and real food. But it is interesting to hear that you feel better taking in the protein powder. Maybe switch to trail mix in combination with your sweet stuff.

3

Working on a PhD in Protein Engineering and Metabolism here.

I like the idea of homemade energy drinks. What do you think about adding a slightly more complex carbohydrate to the drink instead of protein? Like Maltodextrin.

4

Sully - you were one step ahead of me… maybe. Here is my thinking. For 2008/2009 I was on a malto kick using that as a “slow burn” energry source for the longer stuff ( > 2 hr.) but this year I thought by using a faster burning dextrose WITH the protein I could get a sustained energy release PLUS the muscle preserving benefits of protein?? Race day it is all HammerGel and Cytomax.