Hi. I posted a little before about extending my exercise amounts after a 16 or more hour fast. Last week I ran 16.5kms after a 16 hr fast, and broke the fast at 19 hrs. Felt good, no adverse effects/ hunger.
Tomorrow I intend to run 18/18.5kms in a fasted state. I will report back for anyone who is interested 
Please feel free to add your experiences of exercise and fasting here, if you wish.
Cheering us all on!
Hi Stoozie
I just wanted to wish you well with your plans tomorrow - and I hope that your intended run goes well. I didn't realise you ran such long distances, I am very impressed!
I've not done much fasting in my life, but when I have - I have occasionally done some walking before breaking the fast - and that's been fine.
Cheering you on!
Zest
Hey good luck Stoozie and we look forward to hearing how you get on as thats a good distance, so I'm cheering you on... 😊
Exercising in a fasted state burns off your glycogen reserves (about 2,000 calories), and helps get you into ketosis and autophagy, so, 24 hours into my last 68-hour fast, I walked 5.4Km, and 48 hours in I walked 7.1Km. I think that this was over-doing it, I had to take it steady and rest regularly - and I did not feel as good the days after the fast as I had after other fasts. ...but I am 70, and I was disabled for five years.
You may find this study interesting S11m :
A 2011 study by Karen Van Proeyen et al. investigated the effects of training in a glycogen depleted and glycogen-replenished state using twenty young male cyclists. The men were split into two groups, both of which had equivalent diets and training regimens. The first group did all of their training after an overnight fast, while the second group took a carbohydrate-rich breakfast about 90min before their daily training session (a 60-90min bike ride at a fairly hard pace in the morning).
After six weeks of training, both groups had improved a similar amount on a 60-minute time trial. However, there were several changes in the “fasted” group that indicated that their bodies had adapted to more efficiently burn fat as fuel.
First, levels of enzymes associated with fat metabolism increased significantly in the group which trained after the overnight fast, but not in the group which had a large breakfast before training.
Additionally, their fat utilization increased throughout a range of intensities. That is, they could maintain a given pace with less reliance on glycogen, enabling them to last longer in a race without hitting the wall.
Another study (albeit of lower quality, as it used only a handful of untrained men as subjects) by Nybo et al. confirmed the findings of Van Proeyen et al. The subjects who trained in a fasted state in the Nybo et al. paper also increased their fat burning abilities more than the carbo-loaded subjects; furthermore, they also increased their stores of muscular glycogen.
While you might suspect that these changes would have enabled these untrained men to lose more weigh, there was no difference in the weight lost between the men who trained after an overnight fast and the men who did not.
Quoted from: runnersconnect.net/cience-o...
I managed 18kms and ran non-stop for 2 hrs 45 mins (yes I am very slow!).
I then broke my fast at 18hrs with a glass of coconut water to replace my electrolytes.
And a beef and bean burrito.
Because I blimmin' deserved it 
Very well deserved so well done you. 😁
Fasting