Fun Sustainable Transport
Bonking
Bonking on the bike – Michele’s experience during the Tour de France, 1984.
Bonking (or hitting the wall) – suddenly losing energy and the onset of fatigue resulting in a major performance drop. Usually caused by the depletion of glycogen in the body.
On the recent bike ride, I experienced the dreaded Bonk. Its interesting how your body reacts in situations like this and how simple preparation and awareness could have prevented this. Did some reading up on this and here is what I found out.
There is enough sugar in the body to last three minutes. The liver constantly releases sugar from its cells into the blood stream to prevent the sugar level from dropping. The liver has only enough blood sugar to last about 12 hours at rest. During intense exercise your muscles use sugar at a rapid rate. Your liver can run out of stored sugar and you bonk !
To prevent this there are various steps that we can take- constantly keep hydrating yourself thru the ride. Water or any energy drink would do.
- electrolyte would be better than plain water. Rapid skin evaporation can impart a false sense of perspiration. And if you notice you loose quite a bit of salt on long rides. Replenishing this would be ideal
- keep eating and fueling your body thru the ride.
- Wikipedia on Bonking
- http://www.drmirkin.com/fitness/1273.html
- The Science behind Bonking
- Best food for Runners
- Cycling Performance tips, an extremely interesting writeup on how energy is produced in the cell and how we can harness it !
- Fuel on Fat for the long run
[update: Lots of interesting links are pouring in from the readers. Have added them above. Thanks guys]
Comments
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Interesting - Actually the way to avoid bonking is to ensure that your body starts using energy from fat before glycogen depletion. This is done by training at low intensities for long periods of time. This causes the body to "learn" to utilize fat which can keep the body going upto 10 hrs (Fat is the most efficient source of energy!). Consequently if you ride at low intensities, with adequate hydration you can last a fairly long time. During my ultra (nearly 6 hrs of running) I survived on gatorade and 3 energy bars - the only way I could do this was to keep my intensity lower than "normal".
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yup. Thats the ideal I guess. I was also reading up on something called BonkTraining - you do long runs in the morning as soon as you get up, when the level of glycogen is least in ur body, after drinking a cup of coffee !! Looks like this is a fairly interesting subject with varied opinions :)
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Taking a magnesium tablet a day helps. Bananas are a great source of Mg. I had villagers stare at me - (like I am monster), when I ate 9 bananas at once for breakfast ;-)
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Ok! So now I am confused. All my school days - long, long ago - I believed that body burns fat first, then carbohydrates and then proteins (inversely related to the amount of energy that is released per unit). So, what am I missing here? Or did I learn it all wrong - possible. But I go with Bala. Bananas help on long rides.
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:-)) 9 Bananas ??? Wow Amitabh - its Carbs, fats and then proteins, I think :)
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Checkout what exactly balu means by saying low intensity http://cptips.com/bscphys.htm btw is there any killer rides this weekend rohan?
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Interesting article on fat metabolism on RFL. http://groups.google.co.in/group/runnersforlife-bangalore/browse_thread/thread/d5edbb1aaaa7337c/3163c928044d569f?hl=en&lnk=gst&q=Fat+fuel#3163c928044d569f
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mays, Navdeep - awesome links guys ! Thanks a lot. Have updated the article with these links. Highly informative. Mays, the next ride would be the next to next weekend :) Dunno if its going to be a killer :) Hopefully with this knowledge its now :)
