C Law

Is it possible to train your body to become less affected by bonking?

I train (run and bike) in the winter time usually avoiding sugary products. Most of the time it is because I don't do as many long runs and rides in the winter and feel like they are not needed. But even when I do get to longer run and rides I still try and use just water. As I side effect I believe I am kind of getting my body used to 'bonking'. Is it just mental? Is that possible or am I insane? Am I doing more harm than good by limiting my carb intake during workouts? As long as I have a good recovery meal I should be fine no?

Any insight would be helpfull.

WarrenG

Very bad to subject your body to repeated bouts of bonking as your body will adapt and tend to bonk easier in the future. One well-known pro dealt with this issue about 2 years ago.

If your rides are under an hour then water could be okay, but you'll end up having to eat more sugars right afterwards to facilitate good recovery. Any longer than an hour and you really should try to drink about 16-24 oz of sports drink each hour beyond one hour. You will perform better and you'll probably recover just a bit better too.

If you deplete your glycogen stores it will take around 24 hours to replenish them near completely, IF you eat suffcient carbs during that recovery period. If you don't eat enough carbs then you will not recover as quickly as 24 hours. Further training during that period will be further depleting your glycogen reserves.

To give yourself an idea of just how many carb calories you need just for your training, have a look at the various charts based on your size and exercise intensity to see how many calories per hour are burned as well as charts that show your _approximate_ ratio of fats to carbs being burned for energy. This is just a starting point but you may find it useful.

BikeInMN

a true bonk takes a lot longer to recover from compared to a workout where you fueled properly.
a good rule of thumb is - don't bonk and eat to prevent it.
bonking on purpose is counter productive IMO

mcavana

check the rest of your diet... if you are on a "correct" lower carb diet (in other words eating enough greens and drinking enough water) you will not "bonk." The only exception to this is if you just started cutting the sugars, and your body has not gotten used to it yet, or in other words has not gone into ketosis yet. It takes the average persons body a week or so to get used to the change... Once that week has past, if you continue to eat everthing you are supposed to your endorance will be better than ever. (Short hard efforts like sprinting probably will not be as good as when you were not on a low carb diet.)

Remember, it is LOW carb not NO carb!!!!

Plenty of people are going to chime in when they read this and tell you that I am the devil and have evil intentions. Low carbing may not be the most efficient form of fuel, but for MOST people it is an effective way to loose weight. When low carbing, it is still possible to ride a bike efficiently for long distances... without EVER BONKING!!!!

Do some research and make sure your eating enough good carbs. I will not recomend a specific diet because that will give the non believers too much to get all emotional about. Once you are certain that you are eating everything you are supposed to for more than a week, if you still don't feel right, try a different diet!!! Low Carb diets work for MOST people but NOT ALL!!!!

Ok, now watch everyone flip out as they curse me and try to ban me from bike forums!!!

alison_in_oh

*cringe* I have bonked ONCE in my life and I now have a firmly ingrained Pavlovian response to EAT when exercising no matter how poor my body image is at the moment. That horrible nauseous weakness, not believing I can make it just three miles home under my own power, the complete betrayal by my body...how could you DO that on purpose without re-wiring your brain?

*shudders*

WarrenG

Troll.

Yes you can ride with only fat and your muscle proteins for fuel (if you don't mind losing muscle tissue to do that), as long as you ride really slow and don't mind a lower performance. Mike, don't tell people your junk without backing it up with scientific evidence and stop avoiding the answers to the relevant questions.

So Mike, go to PUBMED and show us the scientific studies that support your opinion that I've quoted above.

WarrenG

Actually that may not be true. I once mentioned to my coach that the day after I bonk (hasn't happened in the past 2 years) I usually feel pretty good (as long as I've reloaded well with carbs). He replied that he had heard the same comment from many Euro pro racers that he's coached and that it might be because of some hormones that are released because of that stress, but the damages caused by bonking make it an unsatisfactory way of improving performance.

af895

I found this link interesting: https://www.cptips.com/ovrtrng.htm
Don't know how relevant it is but take it for what it's worth.

CdCf

Wouldn't it be wiser to train to avoid bonking, instead of training to handle actual bonking better?

Machka 

You should not avoid eating while exercising ... food is fuel ... if you run out of fuel, you will bonk, and bonking is a VERY bad thing.

Bonking is when your blood sugar level drops too low -- exactly like an insulin reaction in a diabetic or severe hypoglycemia.

Bonking has a pretty set list of symptoms:

1. "mental" difficulties - you become irritable with little things like all of a sudden your jersey isn't comfortable or something the person riding with you says annoys you ... you start to have trouble concentrating and if you're performing mathematical calculations as you ride, like I do, all of a sudden it becomes hard to add ... you cease conversing with the people you're riding with because all of a sudden it becomes too hard to carry on a conversation.

2. hunger - maybe. I rarely feel hungry when I ride, so I miss this symptom all together, but others experience it.

3. dizziness and weakness - you'll feel light headed, it's hard to focus, your legs just don't have the same power they had.

4. exhaustion - you feel really tired and you've got no energy to turn those pedals.

5. nausea - all of a sudden you just don't want to eat anymore, you feel sick and you just want to lie down somewhere.

6. vomiting, diarhea - you're well into a bonk at this point and if you've reached this point, it is very difficult to recover. But if you ever reach this point, you've got to try to get some calories inside or your situation will get much worse.

7. coma and potential death - this is a very severe stage of bonking which most people don't reach.

Ideally about the time you start feeling irritable, and especially by the time the dizziness and weakness set in, you should eat or drink something with calories ... and keep it up regularly for the next hour or so.


Chances are you won't bonk on a ride of less than 2 hours ... especially if you eat something before you go out, and if you take a bottle of sports drink with you just in case. But if you're out there for longer than that, it's a good idea to consume 250-300 calories per hour (from solid food and/or sports drinks).



As for what to consume, you don't have to eat sugary stuff. In fact, I would stay away from a lot of sugary stuff because sugar causes your blood sugar level to spike, but the sugar doesn't sustain the spike, and your blood sugar level ends up dropping very quickly, sometimes lower than it was before you ate something. Instead, I would suggest consuming complex carbs (low glycemic index stuff), as well as some protein and fat.

*cough

hmm I had no idea what bonking was.. (think its an old fashioned term for sex in Oz).. but a few months ago I went for about a 60k ride on my mtn bike without food..

at about 50k (i got damn hungry at about 40 then it went away) I couldn't keep going, had to lay down in the grass and then the last 10 was an absolute prick to do.
I had to start focusing on going to the next corner and thinking about nothing but that.. and so on.

Does that sound like bonking?

Later I read that you should eat something every 40mins.. is that the general rule?

Machka 

Sounds like the early stages of bonking .... read my response above for a further description of bonking and how often/how much to eat to prevent bonking.

Guest

Yeah. Eat right, train smart, do better with hydration and nutrition.

Koffee

Az B

No, I won't ban you. But I have a new nickname for you:

Mike Cavanaugh... the carb nazi!

"No carbs for you!"

Az <-- Eatin' carbs and losin' weight.

DannoXYZ 

Yeah, I wonder how much weight Mike's lost this past year on his low-carb diet? I've gone from 245lbs to 180lbs since 1-jan-05 with a diet of 60-80% carbs depending upon whether I eat 3000 to 5000 calories a day (I pretty much hold fats & protein constant and raise carbs to match activity level). That's still 500-calories/day lower than my energy expenditures from biking so I lost about 1-lb/week.

Here's a chart on the relative rates of carb vs. fat metabolism based upon exercise intensity:


from Journal Applied Physiology - Determinants of fat oxidation during exercise

As you can see, maximum fat-usage % occurs at about 45-49%. However, to train your body to become more efficient at burning large amounts of fat%, you need to raise your VO2-max and increase your muscular efficiency (type-I fibres) through LSD training at around 10% to 5% below LT.


You never want to get to the point of bonking, it does you no good. Your body will start taking apart perfeclty good muscle to burn for energy and you'll be undoing weeks of training. Fat-metabolism can only occur when you have sufficient carbs to start the lipid-conversion for energy.

While it's possible to burn off 1000-calories of fat while riding at 45% of VO2-max, it'll take you 3-4 hours of riding. Instead, if you focus on training and increasing your fitness (intervals, tempo & LSD workouts), you'll raise your VO2-max, increase the muscle-efficiency and eventually you'll be able to turn off 1000-calories of fat at a 60% pace instead and do that ride faster and in less time (2-3 hours). The goal really should be to increase fitness and condition, rather than just losing fat or weight.


Doesn't this only occur when you eat while sedentary, like sitting on the couch watching TV? Due to the rate of glucose/glycogen consumption on a ride, like 500-600 cal/hr, there's no way you can keep up with that from eating and digesting food (200-250 cal/hr). So your blood-glucose level never rises during a ride, no matter how much you eat.

Insulin levels never actually rise during exercise to cause a rapid drop in blood-glucose. If anything, that would be a good thing since that blood-glucose is actually being transferred into the muscle-cells to rebuild the glycogen supply. This is what happens after a recovery meal, but not during the ride itself.

C Law

Thanks for the responses everyone. I'll take a clif bar and a GU with me on my 15 mile run today.

Cheers

Edit: I have yet to reach the Coma or Death stages of bonking. Most of the others I have covered though

watchman

Another aspect of "bonking" that hasn't been mentioned is the fact that you giving yourself brain damage. The lack of glucose in your brain whilst "bonking" has similar effects as having a mini- stroke. Over time, the cumulative effects of not enough glucose in the brain can start to show. This can be a real problem for diabetics who have frequent low blood sugar episodes or for non-diabetics, bonking.