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bonking with gu?(8 posts)

bonking with gu?Elab
Aug 20, 2001 5:40 PM
Anyone here use GU? How long does the energy last? Is it one of these quick pick ups that give you only 30 minutes of energy? Do you crash hard from it?

re: bonking with gu?DaveG
Aug 20, 2001 6:03 PM
GU is sort of like crack cocaine for cyclists. Provides a quick buzz but not necessarily long. I have not experienced a distinct bonk after using it. To your body its just carbohydrates, including simple sugars and some more complex carbo. GU probably started out as real organic food and then through some sick abomination of nature was turned into the chemical sludge that it is. I only use GU at the end of epic rides to bring my back from the depths of fatigue - it does this very well (especially the caffeinated variety). I'm not sure it is necessary (or economical) to use it all the time. Once I start with it I normally continue using it every 30-45 minutes until the end of the ride.
I use it out of necessitygrandemamou
Aug 21, 2001 3:44 AM
Energy drinks upset my stomach if I'm going hard. It's a real problem when it's hot because I can't drink. They are kind of expensive so I only use them for races,fast training rides and a century. I just load up with power bars or fig newtons and suck down a gu every 30-45 mins and I have never had a problem.
re: bonking with gu?Breezydz
Aug 21, 2001 5:05 AM
No bonk from GU or similar products like Carb-Boom, but don't count on more than 30 mins per pack. Try a bunch of different flavors as taste becomes more of an issue when your stomach is stressed. Please don't leave the packages on the road. I ran the Vermont 50 last year and MTB riders left an horrific number of empty gel packs on the trail, something I'd never seen from trail runners.
Gu packet is only 95 caloriesPdxMark
Aug 21, 2001 6:42 AM
Gu and its brethren seem to have only about 95 calories/packet, versus 225+ calories per Cliff bar and its ilk. Riding 16-20 mph on average you'll burn 500-1000 calories per hour. (The latest Bicycling magazine has a table of calorie burn rates for different speeds.) You need 1-2 packets of Gu every 10 minutes to replace the burned calories. I would bet that any bonking relates more to a lack of total calories than to anything inherent in Gu.
500-1000 calories an hour?Kristin
Aug 21, 2001 6:59 AM
That seems a little high. That would mean that I burned 3000-6000 calories on my 77 mile ride. Is this accurate?
About right...UncleMoe
Aug 21, 2001 7:25 AM
Depending on your weight, 500 calories per hour is a little on the low end, 1000 on the high end. But its a good range for people of average weight. I weigh 170 and I had a link to a website that calculated 830 calories per hour at that speed for me.

However, it depends on other factors too such as muscle mass, how well you are hydrated, etc. I've heard if you aren't hydrated well you burn less calories.
well, there is a weight factor...PdxMark
Aug 21, 2001 9:01 AM
which the Bicycling mag article includes... the numbers I listed correspond to my 165# weight... roughly. Lower weight riders burn fewer calories. Also, the Bicycling mag article is consistent with other sources, like the Bicycling Science book published by MIT Press in 1982 (I think).

As for your ride, Kristin, if you are my weight and rode 20 MPH the whole time on a flat with out drafting, the total would be a little under 4000 calories... Once any of us is in shape, we each have a huge range so long as we get water and calories... but that's my little mantra...

The other tidbit I've discovered is that our glycogen stores (i.e., the calories available for aerobic work) amount to 1000-1500 or 1500-2000 calories (I can't remember which range... dohhhh). Anyway, topped of and carbo-loaded, a 3 hour fast ride is do-able without food - but 4-5 hours is doomed to bonk.

This all means that for rides much more than 50 miles, you (I) will almost certainly need calories... and the measly 95 calories in a Gu pack won't get you very far... but as a bit of variety with other food, it has a reasonably decent proportion of complex carbs and is better than simple sugar stuff like Gatorade

So now I just need to figure out a calculation of energy burned when climbing... any thoughts on that???