The Cycling Bonk

[courtney.rennie]

After our IMC training weekend I learned the hard way about eating well even after the training session is over.  Today in the rain, wind, and cool weather I set out to ride 150 km.  The first four hours went well.  Atsuko joined me 1 hour into the ride for 3 hours which was a great help.  As soon as Atsuko left I rode into the wind up some steep roller hills.  They were not the first hills of the day but the toughest.  Almost immediately I started to feel fuzzy in the head almost like I was starting to bonk.  Up to that point I had been diligent about my fueling.  I ate breakfast before I left, then had a bottle per hour with 250 cal of carbopro and 1 nuun plus a gel.  No straight water though, which I usually don't use unless it's really hot.  I definetely was hydrated because i pee'd at least 7 times in the 6 hour ride.  But i couldn't shake the fuzzy feeling.  There is no way I could have run after the ride.  In fact I called home to let someone know where i was at just in case something happened.

I kept thinking it was nutrition but eating more did not make things better.  Perhaps I need some protein?  I've never incorporated protein into my workouts.  Mentally it was definitely a challenged once Atsuko left me to ride on my own.  But can this make one feel bonky?  Atsuko also suggested that perhaps I was colder than i realized as she was freezing when she got home.

Any thoughts?  I seem to be getting more and more of these low sugar type feelings.   Courtney

[Andrew]

I think the symptoms you are feeling are more likely a shift in amino acids in the brain, rather than a lack of fuel. There is some evidence that Tryptophan may be the culprit...

L-Tryptophan and Carbohydrates
L-tryptophan may be found in turkey and other dietary proteins, but it's actually a carbohydrate-rich (as opposed to protein-rich) meal that increases the level of this amino acid in the brain and leads to serotonin synthesis. Carbohydrates stimulate the pancreas to secrete insulin. When this occurs, some amino acids that compete with tryptophan leave the bloodstream and enter muscle cells. This causes an increase in the relative concentration of tryptophan in the bloodstream. Serotonin is synthesized and you feel that familiar sleepy feeling.

So, here is something to try on your next long ride...take along some BCAA (Branched chain amino acids). This will help keep levels high enough in the bloodstream to compete with the tryptophan and keep the levels lower in the brain, reducing the fatigue.

Ginny has a funny/scary story of nearly falling asleep during her first Ironman race in Kona, about 100miles into the bike ride.

You can purchase a number of different amino acid concoctions. Most are very well-tolerated, and the ones you want in particular, are the ones that contain leucine, isoleucine, valine. Taking these every hour during your long rides and races, may in fact prevent the feelings of fatigue you are experiencing due to the high carb intake you need for fuelling.

You can add a small amount of protein to your fuel, but be careful with this, as most people have some trouble with tolerating it at race pace.

Let me know whether the BCAAs help.

[Atsuko]

Hi Andrew
What are the commercial products of BCAA we can purchase in stores?
Thanks

[Tamara Dantzer]

Hi Atsuko:
When I read this I checked what I use- Gu products both the reg gel and the roctane both have the BCAA  Andrew mentioned.  I a sure there are other products as well- will be interesting to see what others use.

[Atsuko]

Thanks Tamara for your info.
Now I am wondering if it's a good idea to eat gels periodically to prevent the deficit.  I wasn't really planning to eat gels on a ride portion of ironman before.

[GinnySellars]

You don't need to eat gels. You can put BCAAs right into your bottle in powder form. I don't know a name brand, but I just went into Nature's Fare and asked.

[Andrew]

Any commercial BCAA concoction will work, and is usually very well tolerated. GU gels are the only ones that have BCAA in them. I have talked with the E-load maker about adding it to their mix, but there is a problem with formulation they have stated. So, for now, I mix E-gels with GU to help get some BCAA into my regular fuel, and add capsules or powder to my drink for the longer races.

[Peter O'Brien]

THANK YOU!!! At the end of a hard training block, on a long ride, I'll get the same thing.

[Andrew]

To clarify above...I have had more recent conversations with E-Load who are addressing the packaging issues of their gels, and are coming out with a new package this winter, as well as some new flavours. For Ironman Wisconsin I also added BCAA tabs to my salt dispenser, to ensure I had enough to help through the race. I believe there is enough data in the literature to support BCAA use for long training sessions and races lasting longer than 3 hours.