PeteHski

Off the bike whole foods are best, no question. On bike fuelling not so much. As it happens I had my gut bacteria tested recently and it was all positive. It is the big picture that counts rather than individual food items, especially when on-bike fuelling is such a small part of our total diet.

RH Clark

I would be very interested to see exactly how fueling on the bike effects insulin. Spiking insulin is what I wish to avoid.

Are you telling me that it simply isn't possible to ride a bike without consuming pure sugar? I can't subscribe to the idea that cyclists can't perform without refueling from processed carbs.

Iride01 

No he wasn't trying to tell you that. But for some reason you just don't understand.

PeteHski

Of course I’m not telling you that. But if you ride long and hard then simple carbs are the most effective for fuelling performance and they don’t cause the same issues that they do off the bike. The problem with fuelling from whole foods on the bike is that the fiber and complex carbs are not very helpful at all.

I’m only talking about long, fast rides, where fuelling is necessary to avoid bonking. If you ride slower then you can tolerate more fuelling options and need less fuel anyway.

Nutrition is all about the bigger picture. If you eat healthy off the bike, then there is no need to worry about consuming simple carbs to fuel long, hard rides where you need them. If you are genuinely riding hard it is actually difficult to over-consume carbs.

If you want to check your blood glucose while riding, then a glucose monitor is not that expensive. I’ve done it myself for a couple of weeks.

Carbonfiberboy 

Depends on your definition of "perform", doesn't it? You want to ride RAMROD in under 10 hours, STP in under 12, you're gonna need fast carbs, real fast carbs, and lots of them. Doesn't matter whether you can subscribe to that idea or not. If you're riding hard enough to need to fuel with carbs, you won't spike. The Type 1 I ride with fuels with carbs. If you ride moderate for under 2 hours, you don't need to eat anything. If you keep your heart rate under 110, you can fuel with anything and probably shouldn't use fast carbs. PB&J every couple hours is about right. But holding 120 or so for a few hours and you're getting into pure carbs territory. My last STP, I averaged 120 HR in the saddle, ate almost nothing but maltodextrin with a little whey protein. I remember an STP food stop at 100 miles, where I really needed something solid in my stomach, ate a huge muffin, didn't realize until the last bite that I'd also eaten the paper wrapper.

Eating enough becomes a major issue at high exercise levels, which means that stomach emptying becomes an issue. Doesn't matter how much you stuff down, only matters how fast it gets into your blood stream. One can bonk from eating stuff that moves across the stomach wall too slowly. Happens all the time. There's a thing called "sloshy stomach."

PromptCritical 

I have struggled with this issue since stating to get back in shape a year ago after a challenging year medically and being 60+.

As I worked up to 50+ mile rides, I found I had two problems. One is running out of energy and the other is having hard time losing weight when my calorie burned varied 1,000+ calories from day to day (riding days vs. non-riding days).

I've been trying to stay away from carbs and have lost 55+ lbs since Oct, so the plan worked from that aspect.

I now eat some (~1 cup) of steamed white rice the night before I ride more than 40 miles and the morning of the ride I have rice mixed with greek yogurt.

YMMV, but it has worked for me.

Cheers, Mike

Calsun

For energy the choice is between carbs and fat. Dried fruit is high glycemic but raising the blood sugar level when riding is quite different than doing so while sitting at a desk or watching TV. The focus is on weight loss which is unfortunate as half the lost weight is often muscle mass and that lowers the resting metabolic rate and that is not good for long term wealth. But everyone wants a quick fix that requires as little effort as possible.

PeteHski

Yep and if you choose fat there is no point in fuelling up with fat before or during the ride as you already have a practically unlimited supply ready to burn. That sounds great, but only if you ride slow enough to not require carbs. It is possible, but most people will find long rides pretty tough without consuming at least some carbs. Anything else you eat during a ride (fat, protein, fiber) will just get in the way at that point and provide no additional fuel.

Calsun

Studies have shown that with training the body increases its ability to use fat for energy. The catch is that you need to train and most people want something that does not require this level of effort over a long period of time. There is a reason why when more energy is used than is provided by calories a good portion of the loss of tissue is adipose fat.

Iride01 

People that train are going to increase their ability to convert fat to energy at a higher rate whether they use carbohydrates or not during the ride. But for the most part two athletes of equal stamina and ability, the one that uses carb's will stand a better chance of out pacing the other for a longer time. If we are just talking about short rides or a sprint, then it's a toss up.

Jughed

I "trained" and learned about riding on a fat based diet for the past 5 years.

Yes, you can become more efficient at burning fat over time. But as stated above and multiple times in this thread - you are limited by intensity levels. And your RPE will seem higher when burning fat at all intensity levels. My legs just feel flat sluggish or dead when void of carbs, even at Z2.

Another factor - during training, you will naturally up your Z2 power levels. You will eventually cruise along faster using fat energy - but are you really more efficient at burning fat, or just in better shape?

I did a training ride this weekend, 3400'+ of climbing in 21 miles - but the climbing happened in about 6-7 of those miles. 10-21% grades. Unless you have a Z2 of 275-300+w, or weigh a buck twenty - you will not do that type of ride on fat alone. At 180# with a Z2 topping out at 210w - I needed carbs. 40-60 per hour and pre ride carby meal - and I still almost bonked on the last effort.

PeteHski

The thread title itself “is there a low (no) carb fuel for long rides?” can be answered with a simple “no”.

While you can certainly burn stored fat while riding, our fat reserves are practically unlimited (literally weeks of riding fuel) and there is no way that any fat consumed during the ride can be utilised.

Carb reserves on the other hand are very limited and once you run out of them you will suffer. Only riding slower stretches your carb reserves. So it makes sense to replenish simple carbs (sugar) during a long ride. Complex carbs (whole fruit and veg) are harder to break down into useful fuel during a ride. The easiest way to get useful carbs during a ride is via energy drinks and gels. It’s either that or ride much slower to burn mostly fat as energy. As above there is no requirement to replenish fat during a ride (unless there is some other reason for it).

bbbean 

It's easy enough to track what it does to blood glucose through use of a CGM. I trained with a CGM for the first few months of last year, and found that it was difficult, if not impossible to spike from high carb food consumed on the bike (mostly a fructose/maltodextrin drink mix, consuming 80-100g carbs/hour). Supersapiens, among others have studied this in multiple studies. It makes for some interesting reading. Norvo Nordisk has entire team of T1 diabetics, and can direct you to some resources.

FWIW, there are certainly cyclists riding on low carb diets who don't consume lots of sugar or processed foods. They aren't racing. If your definition of "performing" doesn't involve pushing your body to its limits for hours on end, then there are more options. But if you are looking to pin on a number and want to win, you need carbs.

Jughed

Spiking insulin is on my no go list as well.

But

I want to ride fast/hard every so often.

The T2 diabetic is typically having high levels of insulin 24/7. Spikes at every meal with carbs, high levels in between... just overall high levels.

Some (most) T2's on low carb/keto can avoid these spikes and overall high levels, so can "normal" people. The 24/7 issue of high insulin and spikes are not as big of an issue on the correct diet.

Carbing up for a few long rides per year, a few months of hard training 2x per week = very limited amounts and durations of insulin spikes.

For me personally, that is acceptable. I want to be able to ride hard and fast every so often. I want to climb mountains every so often. For me to do that, carbs are required.

I could ride along in Z2 seemingly forever and never eat any carbs - but I want to give it the beans from time to time.

No matter what you do - this type of exercise helps with insulin sensitivity and can help reduce spikes in both insulin and blood glucose.

Keep on riding, heal the body.