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Bonking/hitting the wall in training

Old 11-03-19, 05:57 PM
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DeathCurse7
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Bonking/hitting the wall in training

Are there benefits to bonking in training?

Are the negatives effects?

How do you structure bonking into your training and how often?
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Old 11-03-19, 06:51 PM
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In my 13 years of cycling I never bonked yet....I make sure to fuel myself properly so that it doesn't happen to me.
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Old 11-03-19, 07:07 PM
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This is a query posed by someone who has never bonked on a ride. Nothing good comes of it, there is no benefit outside of the knowledge of how you feel when you're running out of gas, so you can prevent it in the future.

But physically? It sucks. It is something no sane person would do intentionally.
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Old 11-03-19, 08:48 PM
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Yeah, I've bonked. No, it wasn't intentional. Yes, it's completely miserable, no redeeming features. Yes, it's good to bonk when one is starting training, just so one knows what it feels like. Other than that, I don't think it's a feature.
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Old 11-04-19, 03:12 AM
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I also have bonked on a long ride or two ... it's not pretty. As I recall there was dry heaving, an incredible amount of pain, and lying in the ditch wishing I were dead.

And it takes a long time to come out of that level of a bonk because the last thing in the world you want to do is to eat.
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Old 11-04-19, 09:59 AM
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Bonking sucks. I had a hard bonk in August and it was maybe 10 days before I felt strong again. Not recommended. And not a training strategy.
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Old 11-04-19, 07:44 PM
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F*** no you don't want to intentionally bonk. Not only does that ruin your day, but it can compromise recovery enough to ruin ensuing days as well.

What an awful idea.
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Old 11-04-19, 07:46 PM
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Originally Posted by Machka View Post
, and lying in the ditch wishing I were dead.
I've called home from a ditch. I figured curling up in that was warmer than sitting up on the road.

That was a very bad bonk...
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Old 11-04-19, 07:52 PM
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I bonked a couple of times when I started getting serious about my rides that including upping the distance and duration of my rides. The reason for bonking was I wasn't adequately fueling and hydrating plus aggravated by too big of a jump in ride length. During my shorter rides, I was able to avoid crossing into the bonk zone despite even for those rides I wasn't properly hydrated or fueled.

The answer to the OP is to ride properly and stayed fueled and hydrated and you shouldn't bonk. Are you likely to become fatigued at times? Yes. But bonking is a lot more miserable of an experience than becoming fatigued. And no, bonking will not cause you any damage.
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Old 11-04-19, 09:20 PM
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Originally Posted by DeathCurse7 View Post
Are there benefits to bonking in training?

Are the negatives effects?

How do you structure bonking into your training and how often?
Bonking is essentially low blood sugar. If you look up the symptoms of low blood sugar, you'll a list of what you'd be in for if you were to bonk.

Also, bonking is a progression. As indicated in the list below, you might start by feeling a bit shaky and irritable. Ideally, you'd have a quick bite to eat then, but you might not notice or register that a problem is starting for one reason or another (my reason was that it was my first time riding a 600K and riding through the night ... didn't occur to me I'd need to keep eating through the night).

Then you might start to have difficulty doing math ... "We're 400 km into a 600 km so that means we're ... um ... oh this doesn't seem like it should be so difficult 400 and 600 ... I need to relate them somehow. Let's see ... halfway!! No, we're more than halfway ... halfway would be ..."

And your favourite jersey might suddenly become the most uncomfortable thing you own. "It's strangling me!!" "When did the zipper become so scratchy?"

The dizziness might start and you might think then that it would be a good idea to eat something but you're just not hungry anymore and besides it would be way too much effort to reach into your handlebar bag to find something. If only something would come to you instead.

And you start to feel sick so you think you'll try to stop and get off your bicycle for a minute, but that has become really hard to do. You'll have to keep riding till you find a fence or something you can lean on while you get your leg up and over ...


Of course YMMV. It might be a fast progression or a slow progression. You might skip some of the symptoms ... I skip the hungry feeling which is problematic. If I felt hungry it would probably help.

For me, once it hits the nausea point, it's going downhill rather rapidly and it is really hard to regain a not bonked state. It can take hours to get back to feeling just average again nevermind good.


-------------------------------
This site contains a good list (other sites are the same or similar):
https://www.diabetes.org/diabetes/me...l/hypoglycemia

I quote:

From milder, more common indicators to most severe, signs and symptoms of low blood sugar include:

Feeling shaky
Being nervous or anxious
Sweating, chills and clamminess
Irritability or impatience
Confusion
Fast heartbeat
Feeling lightheaded or dizzy
Hunger
Nausea
Color draining from the skin (pallor)
Feeling Sleepy
Feeling weak or having no energy
Blurred/impaired vision
Tingling or numbness in the lips, tongue, or cheeks
Headaches
Coordination problems, clumsiness
Nightmares or crying out during sleep
Seizures
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Old 11-05-19, 08:59 AM
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It's a side effect of either poor planning or execution. It is not an indicator of training or learning anything useful.

Also, don't confuse a bonk with just digging too hard too long in a power zone. That you can still get home from, assuming you execute nutrition correctly and are trained for the overall event distance and back off the intensity.

I was stupid and attacked twice in a road race, failed, then got dropped. But I still made it over the line just fine at SS power and middle of pack finish. No bonk, just had to back off the power after getting dropped to make it to the finish.
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Old 11-06-19, 09:53 AM
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Originally Posted by DeathCurse7 View Post
Are there benefits to bonking in training?

Are the negatives effects?

How do you structure bonking into your training and how often?
Welcome to Bike Forums.

There is a form of training, sometimes called bonk training, that may be part of a periodized training program. The goal of bonk training is to develop the ability to burn a greater percentage of fat versus glycogen for ATP production during cycling. This is useful for cyclists that want to do multi day events with long rides each day.

The protocol is to get up in the morning and go for a two hour ride or so without eating anything. Without any food, ATP production will favor fat burning and try to conserve muscle and liver glycogen. However, the goal is not to actually bonk and run ones body out of muscle and liver glycogen.
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Old 11-15-19, 03:26 PM
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There was a time (late 70's and probably earlier) where the 'depletion phase' of carbohydrate loading before a marathon was 'the thing to do'. This involved cutting carbs for a few days and then doing a long run to deplete most/all of your glycogen reserves. Then, supposedly, when you added carbs back to your diet your body would over-compensate and store more glycogen than normal. Kind of like 'running up to the edge of a bonk'.

AFAIK, this is no longer considered to be effective.

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Old 11-25-19, 08:31 PM
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A cycling aquaintance says he has never bonked, despite being a fit and fast rider. Another friend claimed he was bonking sitting in the car on a long road trip.
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Old 11-26-19, 02:51 AM
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Originally Posted by willibrord View Post
A cycling aquaintance says he has never bonked, despite being a fit and fast rider. Another friend claimed he was bonking sitting in the car on a long road trip.
Both could be correct.
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Old 11-26-19, 11:04 AM
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Originally Posted by Machka View Post
Both could be correct.
I am skeptical of the second case.
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Old 11-26-19, 01:21 PM
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Originally Posted by Hermes View Post
The protocol is to get up in the morning and go for a two hour ride or so without eating anything. Without any food, ATP production will favor fat burning and try to conserve muscle and liver glycogen. However, the goal is not to actually bonk and run ones body out of muscle and liver glycogen.
Bonking is different than fasted rides.
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Old 11-26-19, 06:56 PM
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Originally Posted by willibrord View Post
I am skeptical of the second case.
Having experienced the second, I'm not sceptical.

Bonking is simply low blood sugar ... can happen to anyone if we haven't eaten in a while.
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Old 11-27-19, 08:08 PM
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Terminology sometimes gets in the way. Especially differing definitions of the same term. I always understood bonk to mean low blood sugar. Only food will fix that. I bonked often in my youth when I was careless about my diet and ate way too much sugary junk. Yup, I was actually tested as hypoglycemic. Better diet and exercise fixed the problem. But once it's happened you never forget the sensation or mistake it for any other type of exhaustion.

Cracking is even less precise, and seems to describe dead legs from lactate buildup, especially on climbs or full gas crits. Sometimes we can recover from that just by reducing effort for a few minutes, pedaling (or running) easily until the body converts it to usable fuel, after which sometimes we get that magical second wind.

But bonk sometimes seems to be used to describe dehydration, dead legs while we feel fine otherwise, etc.

The other day I was chattering with a fellow who's been riding only a year but is much stronger (and younger) than I. He said leg pain sometimes interferes with riding, but there was a language barrier so it wasn't clear what kind of pain he was describing.

I tried to figure out, unsuccessfully, whether the fellow was describing an injury that needed rest and/or treatment, muscle soreness that persisted after every ride, or lactate buildup that's transient and clears up with reduced effort, or a good cooldown ride or trainer spin to clear the legs. We couldn't navigate the language barrier.

I tried to suggest my favorite post-ride trick, a heavy marble rolling pin for my legs, but he thought I was talking about a foam roller. I do use a foam roller on my back and glutes, but the heavy marble rolling pin works much better for the legs, especially overcooked quads. Next best thing to a soigneur or masseur. I seldom have sore leg after rides or leg exercises using that trick.

I also would have suggested a true recovery ride, which varies for everyone. In my area a club hosts a couple of weekend recovery rides, but those are based on the fitness of the demographic: teens to early 30s, pros and serious amateurs. I've tagged along with them a couple of times and their recovery ride pace is my full gas pace. I need a true recovery ride afterward, which for me sometimes means a 12 mph loaf around the neighborhood on my hybrid, checking my heart rate to be sure I'm staying in the recovery zone.

That advice may have gotten through because the fellow nodded, smiled and took off on his own rather than following the club. At least I'm hoping what happened.

As usual, some club MAMIL and MUPpet warrior dismissed it with a "HTFU." It's usually one of those guys who enjoys posting Strava times and speeds faster than he's capable of riding solo, but is good at drafting and never takes a pull. One of those guys who boasts he never wastes time on casual or less than full gas rides. Probably because he doesn't want anyone to see his average solo speed is significantly slower than his club rides. It's usually the guys with decent engines and cardio fitness but 25-50 lbs overweight, who rely on drafting the stronger guys, blowing through intersections to avoid posting a slower Strava time, and complain about pedestrians, joggers and pets on the MUP interfering with their pursuit of a sidewalk KOM.

Take advice from those guys with a generous dose of salts, especially if it includes a sprinkling of fish tales and claims for fitness belied by their 40" waists.
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Old 11-27-19, 09:24 PM
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Yes, the issue here is the familiar, "define your terms."

The true bonk, as described in the literature is not a transient drop in blood sugar which can be remedied by eating on the bike. The true bonk is the complete loss of all glycogen, both liver and muscle, then the drop in blood sugar which inevitably follows. This feels indescribably bad. The feeling is bad enough that people on historical death marches would rather be shot by the side of the road than continue. It becomes impossible for even the fittest cyclist to hit over 16 mph on the flat, and even that feels horrible.

There are also partial bonks, either liver or muscle, but not both. When we sleep, our brains use up almost all the glycogen stored in the liver, however our muscle glycogen remains the same as it was when we went to bed. If one gets up and without ingesting adequate carbs and then attempts a strenuous ride for long enough - 50 miles should do it, one will run out of liver glycogen. One rather loses the will to ride and gets a bit dizzy. Of course if one were in ketosis, that wouldn't happen, but OTOH, neither would the strenuous ride. Muscle glycogen will still be mostly there, so that's not a full bonk, just a rather awful feeling, but the cranks still go around. Been there, done that, but I don't think I've ever bonked my muscle glycogen and not the liver. Maybe, hard to say. I've slowly climbed many a hill all by myself toward the end of a fast group ride, but I didn't feel bonked.

1) I think I have had a couple true bonks. The first was on a double metric on which I rode the first 65 miles on the front with a couple riders fitter and stronger than I, riding all the hills near my anaerobic limit. I cramped so badly at that coffee break that I was rolling on the ground, well actually under the table. When we got going again I hung on the back for another 20 miles or so and then I was just gone. I had to soft pedal the rest of the way back, barely hitting 15 on the flat, whereas I was hitting 25 here and there during those first 65 miles. I stayed conscious and upright but that was it. I kept drinking my sports drink. That kept me going, but that's all. One can't replace glycogen on the bike.

2) Another time, I was just not eating enough on a solo century. At about the 50 mile mark, I felt really bad and had to stop. I sat in a ditch and watched the world spin around me. I ate a whole Clif bar, waited about 15 minutes and continued just fine. That was not a bonk, just really low BS.

Back to the OP, example 1 is NOT good training practice. One is going to be really tired and out of it for a couple days. Example 2 is just normal stupidity, no real problem, felt fine after the ride, but not good training practice either.

Riding an hour or two in the morning without eating can be good training, though it's limited training.. One will be training one's fatty acid transport mechanism, but the muscles and aerobic system not so much.
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Old 11-27-19, 10:28 PM
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The only true full depletion bonk I can recall experiencing occurred during NCO academy at Camp Pendleton in the mid 1970s.

My aerobic base conditioning wasn't really suited for the terrain where we trained, the hills of Pendleton. I had mostly commuted by bike 20 miles a day, played racquetball, and trained for boxing in the gym a few days a week. In the gym my only leg work was skipping rope and moving around the ring for shadow boxing and around the heavy bag. I hated running and avoided it other than the relatively easy annual physical fitness test. (Boxing fans might be surprised how little roadwork some boxers do. Most boxing conditioning happens in the gym. Running is seldom really relevant, even for a boxer who "runs" as a defensive tactic. Unless you practice running backward, which Muhammad Ali did, normal running doesn't really work the same muscles. Skipping rope, lunges and squats, shuffling around a lot, with lots of bending from the waist, is more relevant to boxing.) Even without running the rest of the year I could pass the 3-mile PFT run and always exceeded the minimums for sit ups and pull ups since I did those in the gym anyway.

But I was definitely not in shape for the runs we did up hills/mini-mountains in NCO school. Totally different conditioning. After struggling the first hill run I started running the same hills every evening after classes -- in retrospect I should have done those evening hill runs only every other day for the first week or so. It was going okay but one day I changed my diet ("carb loading", rather than my usual near-keto diet) and didn't get enough sleep (I might have had watch that night, I don't remember). Bad combination of conditions.

I felt out halfway through the run. Literally stumbled and fell and could not get up. Not "didn't want to get up" or "I'll just rest here a minute." I *could not* get up.

As a kid on that poor diet I mentioned before I'd had lots of low blood sugar shakes, headaches, etc. So I knew how that felt. And between lots of endurance bike rides and three 3-minute nonstop amateur boxing slugfests, I knew what physical exhaustion felt like. But in those cases I could always keep moving, even if just barely. But that collapse during a hill run at Pendleton was my first, and so far only, true depletion bonk.

That was pretty awful. It felt like one of those waking-dreams where we're half-asleep/half-awake and feel paralyzed.

I've tried to avoid that combination of conditions: ill-advised dietary changes; inadequate rest; over-training on new physical challenges; pushing myself beyond sensible limits.

I've had a few long bike rides, especially in hot weather, where I could tell I would bonk if I continued. So I'd just stop, let the group go if it was a group ride, rest, eat, drink and find my own way home at a comfortable pace. I experience those very seldom now, especially learning what my sustainable pace is in my 60s.

And I've done a few fasting rides close to home just to get a sense of how I'd respond. It went well enough, no problems. Now I do that mostly on the indoor trainer -- easy zone 1 spins for about an hour.
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Old 11-28-19, 06:28 AM
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Originally Posted by Machka View Post
Having experienced the second, I'm not sceptical.

Bonking is simply low blood sugar ... can happen to anyone if we haven't eaten in a while.
No it's not. Bonking is completely depleting all glycogen stores. You can eat something and feel like you're not about to die again, but you won't be able to produce much power for a long time (hours/days) until your glycogen stores are replenished and you've recovered.
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Old 11-28-19, 07:19 PM
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I know that glucose is a preferred fuel for the brain and body but we also have the ability to use fat as a fuel source...So why does a human body bonk and shut down when it runs out of glycogen ?... Most people have enough fat reserves to provide energy for a few days, so why doesn't human body just switch over to fat as a fuel source, so at least the person can function and continue at a slower pace ?
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Old 11-30-19, 05:51 PM
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Is bonking a technical term? Like "hammering" or "noodling"???

I think "bonking" was supposed to describe exercising to the point of inducing low blood sugar levels.

Anyway - there's quite a bit of bonking already in this thread. My knowledge has "hit the wall."

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Old 12-01-19, 11:53 AM
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Originally Posted by wolfchild View Post
I know that glucose is a preferred fuel for the brain and body but we also have the ability to use fat as a fuel source...So why does a human body bonk and shut down when it runs out of glycogen ?... Most people have enough fat reserves to provide energy for a few days, so why doesn't human body just switch over to fat as a fuel source, so at least the person can function and continue at a slower pace ?
That's a good question. We'll have to interrogate our DNA. Why would the current system be selected for?

My guess is that carbs have always been the preferred fuel source. Fruit and shoots, right? Fat was selected as the fall-back fuel because it doesn't have the performance that carbs have. We're not supposed to bonk. I think that's an artificial state induced by modern athletic competition. Experienced randonneurs don't bonk, for instance, because they know how to titrate their resources. I think any experienced spear-and-shield hunter would do the same.

In the wild, our predators were/are sprint hunters and they can out-sprint us. We're not sprint hunters, we're endurance hunters. In theory, we can run down antelopes, although modern marathoners haven't quite been able to document this. OTOH, traditional African hunters do OK. What I'm tying to say I guess is that I can't think of a predator that would cause us to bonk and thus get eaten. I also can't think of a tribal warfare scenario where the opposing sides tried to run each other to death. Bonking a modern artifact.
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