I bonked a couple of times last year and ended up with an ambulance ride to the ER each time. I had gotten progressively dehydrated during those weeks with riding and other outdoor activities, and my blood pressure was in the dirt each time. Each episode was my fault for not paying attention to hydration.

After a lot of miles, I've figured out what works well for me with regard to fuel and fluids. So far, after 3,100 miles in 2017, I've had no issues.

Currently my average ride is about 31 miles. Just before each ride, I take an Endurolyte, a tablespoon of honey, a "stress B" vitamin, and wash it all down with 20 ounces of water. I take one bottle of water and one bottle of water with Skratch hydration mix with me on the bike. I may or may not consume all of both depending on my speed, distance, heat, and humidity. I'm in central Louisiana, and we get the heat/humidity here.

For longer rides, I'll take along some combination of dried pineapple, Endurolytes, honey, peanut butter&crackers, a Clif Bar, and a bag or bags of Skratch powder depending on length/duration of ride. I've learned that those foods and my stomach play well together on longer rides.

For me, starting each ride as specified above has helped. As mentioned above by another respondent, Skratch is pretty good stuff. It seems to work for me.

Good luck. The bonk is frustrating. Stay with it, and experiment with methods of fueling and hydration that will work for you.

Just so we're all on the same page, these are the symptoms of hypoglycemia, aka "bonking":

Heart palpitations
Fatigue
Pale skin
Shakiness
Anxiety
Sweating
Hunger
Irritability
Tingling sensation around the mouth
Crying out during sleep
Confusion, abnormal behavior or both, such as the inability to complete routine tasks
Visual disturbances, such as blurred vision
Seizures
Loss of consciousness

I bonked once, when I went on my first 2 hour ride. I will never bonk again.

If you've experienced a hypoglycemic bonk the worst thing you can do for your body is rely on simple sugar as fuel. That's a guaranteed rebound bonk in 30-60 minutes. Usually it follows a deceptive burst of energy but it doesn't last and the rebound effect can be even worse. It's an indicator for metabolic problems and possible onset of diabetes. For folks with hypoglycemia, simple sugars should be used only for emergency purposes to recover from a bonk and regain muscle coordination to get to a safe place to rest and recover, not for continuing a ride.

Another indicator or signal: If you experience an energy burst from a single beer or similar alcoholic beverage (around 4%-9% ABV) that lasts 30-60 minutes. If that refreshes your energy level comparably to a sugary drink or snack, followed by sudden drowsiness and loss of energy, you may have metabolic indicators for hypoglycemia.

If you've experienced those symptoms it's probably going to be a lifelong battle. You can use simple sugars to recover for emergency purposes, but don't rely on this as fuel to continue a bike ride or other activities. You need to consider a long term solution, including an overall dietary change.

For long term improvement to avoid hypoglycemia the easiest and most efficient diet for long lasting fuel includes more meat and fats, including butter. Tough assignment for vegetarians and vegans.

Carbs are fine for short to moderate term fuel but eventually you'll bonk again without a solid foundation diet that includes the fuel most efficiently provided by meats and fats.

There are many opinions and experts on this stuff. I'm not an expert on anything other than my own body. At age 59 I've been through the hypoglycemia routine since childhood so I know what works for me.

No, the way to avoid bonking is keep consuming sugar. The treatment for bonking is consume sugar. Simple sugars work best as long as you keep consuming them.

For most people this is true. When I was completely bonked I ate a gu and it made me feel worse.

Yep. 25 miles isnt very far on a bike - that should be adequate.

On the sugar drinks, I say to avoid. You're trying to lose weight and those are just empty calories. Use a Sugar-free version of Powerade or similar if you want a sports drink. Otherwise drink water. I ride 40-50 miles daily at a decent pace and normally stop in the middle to eat an energy bar and drink a bottle of water. Or sometimes a banana and I do just fine.

I wouldnt go crazy on carbs as you're not really riding very far, and you are as mentioned, trying to lose weight. Imo your newness to cycling is probably what caused the bad feelings that day. Just hang in there and continue to ride/practice. :)

I hope you'll reconsider that dietary philosophy. It's dangerous for routinely treating hypoglycemia. We're not hummingbirds. Save the simple sugars/glucose for emergencies, which should be rare.

The best way to avoid bonking is a diet that provides for short term and long term energy. That ain't simple sugar or glucose.

Most people have experienced at least one episode of low blood sugar. If you know anyone who gets hangry -- suddenly irritable from hunger -- that's hypoglycemia. But if it happens more often it's probably due to other underlying illnesses and/or chronic dietary problems. But that requires a medical diagnosis.

I carry gel packs, snacks and glucose tablets for emergencies. Glukos tablets from sporting goods stores are good and usually cheaper than the same thing marketed to diabetics in pharmacies. But I don't take 'em unless I feel a bonk coming on, which I try to avoid by eating properly.

Bonking is essentially low blood sugar. In other words, you need to eat. What did you eat before you went out on the ride?

Very difficult to suggest anything because everyone's metabolism is different. I know if I don't have a decent dinner the night before I will be stuffed but I never eat the morning before I ride. Crazy as it sounds after I wake up I might have 2 or 3 cups of coffee with a level teaspoon of honey in them, then I'm off on a 40km loop. If I have breakfast I wouldn't get out the door, I'd be too lethargic, so it's horses for courses.

I ate oatmeal before I left on the 25mi ride.

Oatmeal works well for Rowan (my husband) but not for me. I'm really hungry about half an hour after I eat it.

Maybe you needed a granola bar mid ride.

Must be just fatigue. At 35 Calories per mile, you only burned 875 Calories; easily covered by your body's existing stores. And at 10-11 mph in the flatlands of Florida, even a couple of bridges won't make enough difference to say so in the final Calorie count.

I'd say, your body isn't used to the extended exertion, so don't be afraid to take a nap afterward.

Your diet off the bike can give you 90 minutes of glycogen. That's all the long term energy you can take with you, and just about any diet will do that. After that you need sugar consumed on the bike. And we are just like hummingbirds that way. Sugar transfers energy to our muscles.

Humans break down different sugars and carbohydrates at different rates, at different efficiencies. The fastest and most efficient is glucose. You can consume less of it than the others and use that energy more rapidly. It's easier to auto-titrate or self regulate because the feedback loop is shorter.

I don't understand the opposition to simple sugars while biking.

I'm trying to avoid sugar, at least when I can. It might be quackery but there seems to be enough quacks saying it's bad for you. I figure, when Gatorade tastes good (let alone great) then I'm doing something wrong (ridden too far, too little in, whatever). I think I'd rather bump fat intake if I really need more calories (eggs, nuts).

But I'm not trying to ride at 90% effort for hours at a time either.

one would think that, from some of the things written here, that mammals hadn't evolved over millions of years a natural inclination to eat sensibly by virtue of a thing called 'appetite'. but rather to consciously decide what foods to and when to eat them. :foo:

I dunno, when I eat according to my appetite, I tend to put on weight. Other times I know I must force myself to drink water, I might not be thirsty but I know I'm dehydrated.

It's a weird thing, sometimes the mind needs to take control over what the body "thinks" it needs. Furthermore, I'm not sure evolution could have predicted the subsidies given to the food industry (nor could it predict that we'll all have couches and TV's someday).

Lol, and remote controls, I have 4 remotes on the table next to my recliner, one for the tv, one for the firestik, one for the chromecast and one for the cd player.

Lucky you. My two remotes keep saying "no daddy, you go do it." Ingrates!

My FUELING for a ride begins the day before......I eat properly to top off glycogen stores for overnight sleeping. Sleep does happen to consume some of those stores and thus a proper early morning re-topping is in order if a long ride is planned. Topping off with OATMEAL an hour before going out on a ride MIGHT CAUSE ISSUES because the oatmeal will still be digesting (90 minutes) in the stomach requiring the use of oxygenated blood to be digested.

Helpful digesting times.....

Digestion Time Of Foods Is The Time Spent In The Stomach Before Emptying.

While riding if I have that helping of nuts, pb&j, cheese, a potato, some chips, pretzels...etc it all requires oxygenated blood to be digested and the longer it takes to digest-the less blood is available for my leg muscles and BRAIN ACTIVITY. Quick, easily digested foods i.e.- sugars(candy), gels, water laden fruits quickly provides energy to prevent bonking but I follow with proper continuation of fueling so as to NOT CAUSE AN ISSUE after consuming. NOTE--that burger might taste great and fill my stomach BUT it will not taste great if it finds itself coming up when attacking a climb shortly after consumption. :eek:

NOTE--gels have been formulated to pass on the energy within minutes of consumption. One can make one's own gel to reduce the cost per serving and garbage factor.

The harder and more intense the activity, the greater the need for proper and adequate fueling. Once one gets behind in fueling/hydration it becomes harder to maintain levels of higher physical output.

My prostate cancer treatment protocol has me taking Metformin which is often prescribed for diabetes. It prevent the digestion/absorption of carbs to create glycogen. EVERY DAY I wake up without the stores needed for normal daily activity and even worse when heading out for a good day's ride. I rise 4 to 5 hours before riding to take my thyroid meds. allowing 1 to 2 hours before eating which then gives my system enough time for digestion/topping of the reduced carbs for glycogen production.

As noted in post 14, true bonking is the depletion of glycogen supplies. The term has been bastardized to include any time one feels tired or otherwise not right during or after a ride (e.g. as a result of becoming dehydrated).

Eating a lot of sugar while sedentary is bad for you, sure. But replenishing sugar while riding a bike is good for you. It prevents hypoglycemia, the topic of this thread.

We didn't evolve to ride bikes. We evolved to walk very long distances slowly, punctuated by sprints, so we're very efficient at that and the feedback loops in our gut and nervous system work well at that frequency. Riding a bike at 20mph for 70 miles can make you hypoglycemic before your brain registers hunger. We also need to drink before we're thirsty under those conditions.

We have consciously decided to live in a way that isn't exactly what we evolved for, so we have to consciously decide how to eat and drink (and sometimes breathe).

If you are/tend to be hypoglycemic, then do say so. otherwise....

25 miles shouldn't be over 1000 calories, probably closer to 800. "Bonking" (ie burning all the sugar from your blood and liver, and overtaxing your energy production systems to where they go into shock and shut down) is unlikely.

You are probably just teaching your body that it has to burn fat instead of sugar, and when it burns sugar it has to replenish by converting back from fat.

Also, you were probably dehydrated. drink more water. no just on the bike. the night before, and after the ride too.

You can try gatorade on the bike... half strength, with an added pinch of morton lite (potassium + sodium). that way you arent taking on as much sugar as full strength gatorade.

Fair enough. I'm going to run the risk, it's taken a while to get rid of my sweet tooth, and I don't want to encourage it to come back. I'm going to limit myself to a serving of fruit, maybe two, while on the bike, nothing more. Don't have time to ride for hours on end anyhow; and if I do... I might as well pace myself a bit and let the digestive tract do what it's good at.

How long do you ride? Bonking is really only a problem for novice riders around 1 hour, experienced riders around 1.5 hours.

Bonking is Low Blood Sugar in your Brain.
It can occur anytime the Sugar level goes Down