delbiker1 

I have a naturally fast metabolism. I would probably struggle to do a 40 mile ride if I had been fasting since the day before. Just not worth whatever benefits one supposedly gets from the fasting. Not fueling up afterword is not an option for me.

Jbo26

Same type of concept of the 16/8 intermittent fasting just compounded. These types of rides kick your body into a better form of ketosis. More growth hormone, insane amount of autophagy and body repair. The 16 hour fast can easily go past 36 hours with the help of these fasted Century rides.

Maelochs

I have a ton of fat to burn too ... but fat tends to burn slowly and steadily---a diesel engine---and this leaves an energy deficit if one tries to say , attack a hill, or sprint to catch alight.

You however, seem to have built up this capacity. if it works, it works ..... we are all different.

Jbo26

Keep doing what works for you. Cycling is a different adventure for everyone.

RH Clark

So far it works for me. When I started intermittent fasting ,I would feel like I needed food a lot sooner than I do now. I always carry good quality carbs though and would eat if I felt like I needed it. I just bought my first road bike and am not quite up to century rides but I hope to be soon. I do think that anyone needs to listen to their body though and not push it beyond what they feel is healthy, and that gets more critical with age I think. I'm not saying we don't need to push some but knowing how much is too much becomes more critical. I would also think that holds true with anyone trying to drop weight, who may not be at optimal condition.

aplcr0331

How are you measuring calorie burn?

I did 103 miles 3,400 feet of climbing avg 17.8 and only burned 3700cal based on power meter and hr monitor.

tomato coupe

Where do your calorie numbers come from? Burning 6,000 calories over 6 hours implies an average power output of roughly 300 W. Can you do that?

guachi

190 Watts and 5,200 calories don't line up. 1,000+ calories per hour is about 300 Watts.

Jbo26

chest strap HR monitor

Jbo26

Watts are not accurate. Just a guesstimate from Strava. I use polar bike computer and polar chest strap HR monitor (Very accurate). When pulled into Strava the Strava app assigns watts as a guess.

Atlas Shrugged

If your averaging 32km an hour plus over 1700 meters elevation gain for sure we are looking at north of 300 watts much less fasted. A strong cyclist for sure.

tomato coupe

Realistically, you should cut the calorie estimate by half.

seventwosteve

this is true for me as well, often bike fasted, prefer fasted, but once i cross in to the 50-60 range i've ventured in to the light headed realm at times..... not every time.... but i know i'm more at risk of it

caloso

6000kcal seems. . . optimistic.

CliffordK

I don't see elevation listed, but that looks like a fairly flat route. However, 20 MPH average for a century is pretty impressive. Solo? Group?

Was there a question in here somewhere? For a ride like that, I'd certainly like to have a bite before leaving, but I can go a few hours without eating. Although, I do prefer to stop and eat from time to time.

As far as eating, look at your speed during the ride. Say you started the first 50 miles at 25 MPH, and finished the second 50 miles at say 16 MPH, then it might be indicative of needing to eat (or wind, or other factors).

noimagination

Exercise physiology, food metabolism and the interplay between the two and how they affect body weight are hugely complex, and are extremely poorly understood - even within individuals, without trying to generalize for populations. I would caution against throwing around a bunch of terms like ketolysis, "burning" fat vs. muscle, insulin levels, etc. Even something as simple as calories consumed < calories expended = weight loss is fraught with exceptions and contradictory evidence.

If you are following some type of program, then great, just be honest with yourself about the effects and be objective about the effects of any changes. People tend to get invested in a program and ignore harmful effects, or disregard the possibility that there may be better strategies, or disregard changes in the effectiveness of the program due to other changes (age, etc.). This is certainly understandable, because it takes a huge amount of mental, physical and emotional effort to stick to a lifestyle change.

I guess it all boils down to: stay humble and pay close attention to what your body is trying to tell you.

aplcr0331

6,000? Uh, hope.

“Dr Howard Hurst, a senior lecturer in sport, exercise and nutrition sciences at the University of Central Lancashire, told me that as far as he can work out, “Strava has a margin of error somewhere between 25 and 50%”

https://support.strava.com/hc/en-us/...bile_site=true

https://support.strava.com/hc/en-us/...bile_site=true

https://support.strava.com/hc/en-us/...bile_site=true

https://www.yellowjersey.co.uk/the-d...calorie-count/

https://strava.zendesk.com/entries/2...ie-Calculation

Without a power meter those calories burned are completely worthless.

DrIsotope

But don't forget-- 100 miles, +5,000ft of vertical, 20mph average. Just you know, typical pro-caliber numbers. But hey, I dunno. Maybe the OP weighs 60kg and has like 6W/kg FTP.

I did a solo 109 miles w/ 6,100ft of vertical (all in the middle-nested 20 miles) @ an average of 15.7mph and 4,100kcal. But I'm like 95kg, and my FTP is nothing to brag about.

I also ate like a starved horse.

badger1

Yup. But wth, this is teh Biek Forms -- the land that reality forgot.

veganbikes

Just like a car running on fumes, riding your bike without the fuel your body needs is not a good thing. Be smart, don't bonk, it isn't fun and can really ruin a ride. There is good reason you don't find a lot of people who brag about running on fumes just like you won't find a ton of people who believe the Earth is shaped like a triangle and filled with moon farts.

veganbikes

You don't need to kill it, it will bonk soon enough ; )

CliffordK

You know, the OP has written very little about his ride. "Fasted Century ride?"

With simply an uploaded photo showing a 100 mile loop on Strava.

So...

"Fasted/Fasting"...

Or perhaps he intended to discuss speed rather than diet.

"Faster/Fastest/Plain Fast"

It becomes difficult to interpret one's intentions when so very little is written.

Perhaps a picture isn't worth a thousand words.

Rajflyboy

100 miles at 20 mph

very well done

tomato coupe

3 threads started by the OP, all within 90 minutes of his very first post:
"Fasted Cycling"
"Fasted Century Ride?"
"Fastest Century Ride?"

Atlas Shrugged

The fact the OP was able to do a 5 hour century complete with +5,000 feet fasted obviously it was done with a lower heart rate burning fat and ketones. With very high levels of fitness bonking can be avoided.