In reading Friel’s book, he mentions that taking glycerol will enable your body to retain 50% more fluid (thus decreasing your chances of dehydration). He also states some study that says that the atheletes who took glycerol, their body temps increased 40% less, heart rate was 5% lower, and a an overall 32% improvement in endurance.
I have never heard it mentioned in this forum. Is there any validity to the above, and does anyone use it? Hell, is it legal/ethical?
Danke.
I recently read that section in the TTB also. 32% improvement in endurance sounded great, if not unbelievable. I am also interested in the basic questions: any health effects?/ is it legal?/ experience showing the benefits? / where would you get it?
Perhaps a decade ago, I tried this. I sweat a lot (like 1oz/minute on the bike, and up to 1lb/mile on the run; try drinking that back!), so I checked it out. I used it twice: once on a long hot bike ride, and again before a 52mi bike road race. The first time worked very well, with no side effects, and no extra peeing. The second time had a problem: because of bad weather, the start of the race was delayed. I found myself having to pee every 5-10 minutes for about 45 minutes before the race.
A quick search on the Web revealed this: http://www.cptips.com/glycerl.htm
and this: http://www.rice.edu/~jenky/sports/glycerol.html
Although both articles suggest that the use of glycerol doesn’t affect sweat rate and body temperature, they don’t address the idea that using glycerol can increase the total amount of water in the body, which is why I tried it. I can’t possibly drink enough to replace the sweat I lose; the glycerol allowed me to store (intracellularly, I believe) about 2L of water more than if I was just hydrated. That’s a couple of extra hours of racing.
Ken Lehner
A better article (with some peer review): http://www.sportsci.org/traintech/glycerol/rar.htm
This one seems more positive.
Ken Lehner
Isn’t the human body like 90% water? I don’t see how glycerol is going to help me retain an additional 50% (~ 80 lbs!) of fluid.
I’m going to stick with salt tablets until more research is done.
I’ll read the articles. Strange that you said it made you pee more, as I had heard that taking it would make you pee less…thus retain more water.
John, I took it to mean that you your hydration loss is reduced by 50% (or increase your ability to retain water by 50%), not increase your H2O in your body by 50%.
Glycerol(ine) is available in natural/health food stores.
I had to pee more because I was not exercising (the race had been delayed an hour or so). My body was processing the glycerol, thus freeing up water that had to go somewhere…
Ken Lehner
Check out “Liquid Endurance” at the e-caps/hammer nutrition site"
http://www.e-caps.com/products/detail.cfm?div=Products&cat=ECAPS&det=Liquid%20Endurance&sku=LE
Here are some comments from the Kevin Sayers UltRunR site:
http://www.ultrunr.com/glycerin.html
Here’s an article from crucible fitness:
http://www.cruciblefitness.com/nutrition/etips/Glycerol.htm
There are lots of other articles if you go to google and do a search on “hyperhydration glycerol”.
Another way to hyperhydrate is just eat more salt several days prior, along with carbo loading which also increases fluid retention. Neither have the potential side effects of glycerol.
I take it the morning of each important race I do. I’ve noticed that I do hang on to water (pee) longer than usual. Hey, I don’t think it does all the things Friel claims in his book, but why not hedge your bets? I do ironman distance races in hot places (are there any cold ones?) and have never had a dehydration problem, but I make sure to always take in about 1 liter per hour of water or fluid. Like all things, try it in training first.