yea i do this in a large degree----for me though the goal is to never bonk, the goal is to take in as few as calories necessary to complete my ride at a decent pace.
I had a ride this morning, 56 miles in 170 mins and only took with me two bottles of lightly carbed fluid. And i hit the wall to some degree, lets say, i could have used more carbs. Then again, im not in excellent shape yet—ive noticed in the past that the better shape i get into, the less i need to eat on a ride to do well.
I’ve talked to marathoners who have told me of similiar practices, they have said that they do their long runs building up the mileage without eating so that they eventually can get to 2-3 hr runs without consuming anything but maybe a little gatorade to keep the salt up in the bloodstream.
I would recommend taking more food with you then you’d like to eat just in case the ride doesnt go as well as you would have hoped, but just know that youre only to reach into your pocket when you feel the emptiness approaching.
bonking is not only a terrible sensation, but a very destructive physiological effect. as far as i know, the full blown bonk involves your body attempting to begin burning proteins for fuel (the same thing you are trying to build up). not good.
but… i think you can train your metabolism to become much more efficient for endurance events; ie, better at burning fats. one of the biggest proponents of this, is triathlon coach michael mccormack. he is extremely accomplished, and has written an article on this issue.
excerpt: “My method for improving my fuel efficiency was quite simple; controlled deprivation. Basically, this meant eating less in training while taking care to not go over the edge and bonk.”
my personal advice is to always have a little something extra packed with you (gu pack or 2). last year i foolishly bonked on my bike and deleriously rode to a grocery store. i was literally panicked while i went to the candy isle and started ripping into the stuff with my helmet on and everything. at the register i was shaking. if i had no money with me, i still would have eaten and worried about settlement after it was in my system. fortunately, i always keep a 20 in my patch kit.
I’m with the Monkey on this one. DON’T BONK. You really don’t need to be that destructive on your protein source (muscle), and it is a hit on your immune system at the same time. If you ever do accidentally bonk, for whatever reason, ASAP refuel with simple sugars, complex ones AND protein. You are trying to minimize the damage at this point.
This type of training was all the rage…in football…back in the Vince Lombardi age. It wasn’t very smart. I wouldn’t do it, at least, not on purpose.
Jeremy and The Monkey (sounds like a cartoon, huh?) –
I had another gatorade and 2 king size payday candy bars in my backpack [In the future I’ll take some PBJ’s w/ me too). At the 2 hour mark, I came to a point where I decided if I was strong enough to do another hour, or if I needed something to eat. I felt fine, so I kept going (without eating).
I know (from reading, not experience) that bonking is not a good thing … I don’t know if one can actually bonk on 3 hours of training or not. What I was/am doing is more along the lines of “controlled deprivation” … the term “Bonk Training”, I think is somewhat in jest … since you would never want to actually “Bonk”.
There are some very good suggestions in this thread.
The general answer is - NO. Bonk training is not a good idea… but then again, I may be misunderstanding your concept of bonking.
According to Friel, The diet references and training are based in periodization terms. Or as Friel put it, “In the Prep and Base period the diet should shift toward fat and away from carbohydrate. Protein remains fairly constant throughout the year. The purpose for this shift is to improve the body’s propensity to burn fat for fuel while sparing glycogen.” I don’t believe he ever referenced specific training workouts that promote a water only training session (I could be wrong). And, I don’t know of any training method that suggests this method to improve “fat burning”.
The reason is probably because the recovery period for such a training method is more intensive than is gained through the process of forcing the body into glycogen depletion. In essence, more would be lost than gained from “bonking” regardless of it’s intended purpose. Leaving recovery out the training equation is not a wise method. So, lets assume you train your body to “burn fat” more efficiently by “bonking”… chances are these kinds of stress will reduce the bodies ability to recover and result in net loss of fitness and not a gain.
TT, It’s possible to bonk in three hrs or less doing low intensity ride/run. IMHO it’s related to how much glycogen that is stored prior to the training and how much you replace it during.
I bonked 1:55 into my 20mi marathon training run. I think largely because the night before I only ate a grilled grouper salad. Not alot of carbs in that!!! I ate on my run every 45min. drank gatoraid at the same time but I still bonked. I am glad I had gels with me or I would have been in bad shape. I know I never want to do it again, the marathon was a piece of cake compared to that run.
I dont see any sense in this approach to training. You burn fat at all speeds if you stay aerob and you burn about the same amount. The only thing changing with speed is the amount of carbs used (and with that the fat percantage).
So if you average 500cal an hour (very easy training) maybe 250 is fat (very good) and 250 carbs (gives you 50% energy from fat). Uping the intensity to 750cal per hour will still let you burn 250 cal of fat (so down goes the myth of going slow to burn more fat) and 500cal of carbs.
The fat burining will go on, as long as you have enough carbs on board. (as fat metabolism need carbs) On board means in you blood, liver and muscles. In fact a little bit shorter, as the body keeps some reserve for your heart and brain. So if you store 2000cal (or 2500 on race day carbing up before) 3-4 hours of moderate intensity (750cal) training will let you bonk - which means no more fat burning.
The only way to train (at a training relevant speed - not to crawl, hike or jogg) longer than 3-4 hours therefore is, to add carbs during the training. You can ingest about 300-400 calories from carbs per hour, so you can calculate, why the normale Ironman brings everybody to the limits of energy management.
Now obviously a 3hour ride is not long enough to let you bonk if you start well nourished (so not empty in the morning) and maintain a pace under or at about 750cal per hour. Why that should have any additional training effect - except for the brain - is beyond me. Fat metabloizm is a normal function of our body, it does not have to be activated, you do not use tricks to activate oxygen takeup (breathing) either. If you want to train your body to metabolize fat for fuel, just go long and slow replacing about 200-300 cal an hour. Long is longer than 3 hours though.
Now to that idea to loose weight that way - very bad idea. The food during and after a ride is caled recovery food for a reason - to replace lost glycogen as fast as possible is of high importance for recovery and your ability to go out and burn fat again. Ingesting the exact amount of lost carbs and at least 15g of high quality protein is important for not getting sick. So if you really need to loose some weight - well no way around to saying no to dessert - sorry. Skipping recovery food and having the tiramisu in the evening wont do it.
I know RAAM winners (relay team), that never use empty stomach training, I use it in the morning for swims (the only reason being to avoid anything coming up if some intervals torture us too much ), runs under 2 hours but never for bike rides. And I ALWAYS have a reserve gel and some money to buy coke at a petrol stop with me to avoid bonking. Training bonking seems like training downhill crashing.
I’m not really disputing the idea that if the body has glycogen available it will have the tendency to burn it more readily, I’m questioning the statement that carbs are necessary for the continued burning of fat.
As far as I’ve been able to find out the metabolism of fat and of glycogen happen in separate cycles until they are both converted to pyruvate. Also as far as I can tell neither cycle is dependent on a product that is only available from the other cycle.
But I’m not a biochemist either. Two people in this thread have stated that fat burning is dependant on carbs. Just trying to find out if that’s true or not.
Fat burns in a glucose flame - is the old adage I recall from physiology. But that doesn’t mean the glucose has to come from carb intake. In the absence of carbs it will come from muscle tissue - not a good thing in the long term.
Although fat metabolism can be improved (eating a high fat diet for several weeks will do it too) I am not sure why you would want to become that efficient at fat burning. I started exercising years ago so I could get away with eating more and now with a focus on 6-8 bouts of exercise I have gotten so efficient I can barely eat anything extra. I have done 8 hour rides on only 600 cal. IT SUCKS.
Fat burns in a glucose flame - is the old adage I recall from physiology. But that doesn’t mean the glucose has to come from carb intake. In the absence of carbs it will come from muscle tissue - not a good thing in the long term.
Although fat metabolism can be improved (eating a high fat diet for several weeks will do it too) I am not sure why you would want to become that efficient at fat burning. I started exercising years ago so I could get away with eating more and now with a focus on 6-8 bouts of exercise I have gotten so efficient I can barely eat anything extra. I have done 8 hour rides on only 600 cal. IT SUCKS.
The breaking down of muscle fibre is too slow to provide glucose during racing/exercising. Therefore we bonk. Would it be faster, you could do an ironman on water alone - just sacrificing some muscle. You can’t. During rest, your theory is true of course, which is why we don’t die after a weak of fasting.
The second “point” is completely pointless though. You can eat extra of course, as you burn your own fat for that calories. So during that 8 hours you still burn a minimum of 4000 calories (if you really ride), just that they come (mainly) from your fat tissue. So you can treat yourselve to your favorite food afterwards - without getting fatter - just replacing what you burned. Actually - if the figures were right - you are very lucky it is very easy to get very lean than.
adal wrote: Training bonking seems like training downhill crashing.
I love that analogy!
Recovery is what getting more fit is all about. Yes, you have to work in order to have something from which to recover, but, during the work phase isn’t the time to be restricting fuel. Restrict fuel intake during the correct time during recovery (not the first few hours, of course), and you’ll get more fit, more quickly, and can still “teach” your fat-burning system to be more efficient.
Ripper wrote: It is true. The reason it is true is that although both fat and carbohydrate can be converted to acetyl-CoA and enter the Kreb’s cycle, pyruvate can only be formed from carbohydrate. From there the carbons can be recycled back to glucose, or can be used to form the intermediates of the Kreb’s cycle. Since the latter are continually being drawn upon for other purposes, they must be continually replenished from carbohydrates, a process called anaplerosis. This is the basis for the saying “fats burn in a carbohydrate flame.”
See? Don’t do the bonk training scheme. It results in a decrease of workload achieved during that ride, it could set you up for consuming your own protein stores (muscle), and it makes it harder to recover from a not-as-high-of-a-workload-as-could-have-been-possible workout. Bad news all around. Just say no.
According to a chart in a Tim Noakes’s “Lore of running” approximately 30% of energy is supplied by fat upon exercise start and may increase 62% or so after 4 hrs or so.
Of course this is dependent on ALOT of factors including intensity, athletic conditioning, pre exercise meal etc.
At intensities of 95%+ VO2max 100% carbohydrate is burned. Some research shows that fat burning alone can only sustain exercise up to 50% VO2max.
MJuric wrote: According to a chart in a Tim Noakes’s “Lore of running” approximately 30% of energy is supplied by fat upon exercise start and may increase 62% or so after 4 hrs or so.
Remember, one of the reasons the fat % being burned after 4 hrs is that you’ve used up your initial stores of glycogen, and gluconeogenisis isn’t keeping up with the demand, nor is your ingestion/processing of carbohydrates. So, your % of total energy being provided from your fat stores increases partly because your overall energy burning has decreased…because your available sugar supply has dropped.
Do you have any links, books articles etc that would go into further detail on this? Preferably in non PHD terms.
Like I mentioned in another thread I’ve heard this before but haven’t really seen anything to prove or disprove it.
Seems like this, and correct me if I’m wrong, would drive a nail into the idea of Atkins and being “low on carbs” as a good thing. As if you are in a glycogen depleted state you would not be able to burn fat either. Thus a “bonk” would not only mean an end to energy from glycogen and glucose but from fat also, leaving only protein as an energy source. And pretty much any glucose being created from protein is being used in major organs certainly not for muscle energy at that point.
Just looking for an answer. If it is true, and I really don’t know not just trying to controversial, that fat burning ceases upon the depletion of glucose/glycogen then anything that creates a glycogen depleted stated should also keep one from burning fat.
Somehow I doubt that the statement, “fat oxidation is “dependent” on glucose” is 100% true as this would mean a near shutdown situation upon glycogen depletion and or simply starvation. I suspect this as from what I’ve read protein simply does not provide enough energy to sustain much, if any activity.
Again from Noakes, “…only under extreme conditions such as complete starvation or prolonged excercise(especially under conditions of carbohydrate depletion) does protein’s contribution reach even 10% of total energy production (Lemon & Mullin, 1980)”
This to me means that upon glycogen depletion 90% of energy is coming from other sources, not likely glycogen since it’s depleted so only thing left is fat. However I have not looked up the actual (Lemon & Mullin, 1980) study so I could be wrong here too.
So even if fat oxidation is 100% reliant on glucose I suspect that there must be some other method or cycle used upon the depletion glucose.
Again I really have no idea on this and am looking for answers rather than saying anyone is correct or incorrect.
), runs under 2 hours but never for bike rides. And I ALWAYS have a reserve gel and some money to buy coke at a petrol stop with me to avoid bonking. Training bonking seems like training downhill crashing.