Fast – day#13 / looking back ~

Weight: 74.8
Body fat: 26.8%
BMI: 23.9
RHR: 59bpm
Sleep: 6hrs 32min 
BP: 105/61 @67bpm


When I look back, I was quite daunted by the prospect of not eating for fourteen days. I was genuinely not sure whether I could stick it out. That’s one of the reasons I decided to make my fast public – I figured it would be harder for me to bail if I had people watching me from afar.

The other reason I decided to go public is because I wanted to provide good solid medical information about fasting for those that might be interested. I’ve done that in the posting of excerpts from Dr Jason Fung’s book, The Complete Guide To Fasting.

And over these past 13 days I’ve had a wonderful response from people around the world, contacting me telling me that they’re going to undertake a fast, some telling me that what I’m doing has been inspirational. That’s enormously gratifying.

Bu I have to say, at the outset I was scared. And the last time I felt that kind of fear was before I walked my first Camino, in 2013. And now, looking back, I realise that the way I’ve gotten through this fast is the way I got through the Camino – by increments.

In my Camino memoir book, The Way, My Way, I talk about the power of increments. That you can achieve great things, seemingly impossible things, by approaching it incrementally. You look at a map of Spain and you think there’s no way I can walk across that country. No way.

Then you look at the map again and you look at the next town ahead of you – a day’s walk. I can do that, you say to yourself. And you do it, then that night you look at the map again and you see the next town on your route and you say I can do that. And after thirty days you’ve walked 800kms across Spain!

The power of increments.
As I say in my book:

I could never get over it. I would stand on a hill and look into the distance and see a village. And then I’d set off, and within a few hours I was actually walking into that village. The power of the small step. A lot of small steps gets you extraordinary distances. If you keep taking those small steps.  I began to think of what else I could achieve, through small steps, Through increments. If I ate a little less each day, I could lose weight. If I did a little more exercise each day I could get fitter. If I spent a little less each day I could save more. You don’t have to take big strides. Little steps are fine, but just keep taking them. And then you find you’ve walked across a country.

Same deal with this fast. The prospect of not eating for 2 weeks seemed impossible, but I discovered that if I just focused on not eating that day, and that day only, then not eating for one day was do-able. And then I’d wake up the next day I’d do the same. And now here I am, 13 days in, and I’m almost at the finish line. I’ve almost walked all the way across the country.

So here’s the last excerpt from Dr. Fung that I’m going to post. It’s a series of Q&A’s. If you’re interested in doing a fast, I highly recommend you read his book – here’s an Amazon link:

The Complete Guide to Fasting – Heal Your Body Through Intermittent, Alternate-Day, and Extended Fasting


Will fasting make me cranky? 

Interestingly, this has not been a problem in our Intensive Dietary Management Program, despite years of experience and hundreds of patients. Similarly, members of religions that embrace routine fasting are not known to be cranky. For example, nobody would stereotype a Buddhist monk, who engages in fasting almost daily, as a cranky guy. 

I think that when people become irritable when they don’t eat, it’s because they expect to be cranky, so they act out their role in a self-fulfilling prophecy. When we normalize the idea of fasting in their minds, they forget to become cranky. Will fasting make me tired? No. In our experience at the Intensive Dietary Management Program, the opposite is true. Many people find that they have more energy during a fast—probably due to increased adrenaline. 

You’ll find that you have plenty of energy for all the normal activities of daily living. Persistent fatigue is not a normal part of fasting. If you experience excessive fatigue, you should stop fasting immediately and see your doctor. Will fasting make me confused or forgetful? No. You should not experience any decrease in memory or concentration during your fast. On the contrary, fasting improves mental clarity and acuity. Over the long term, fasting may actually help improve memory. One theory is that fasting activates a form of cellular cleansing called autophagy that may help prevent age-associated memory loss.

Does fasting lead to overeating? 

The simple answer is yes, you will eat more than usual immediately after fasting. However, the amount of food eaten above the baseline on nonfasting days is not enough to offset the preceding fast. A study of thirty-six-hour fasts shows that the meal taken after the fast is almost 20 percent larger than usual, but over the entire two-day period, there was still a net deficit of 1,958 calories. The amount “overeaten” did not nearly compensate for the fast. The study concludes, “A 36-hour fast … did not induce a powerful, unconditioned stimulus to compensate on the subsequent day.” 

My stomach is always growling. What can I do? Try drinking some mineral water. The mechanism is unclear, but it is believed that some of the minerals help settle the stomach. I take medications with food. What can I do during fasting? Certain medications may cause side effects on an empty stomach: Aspirin can cause stomach upset or even ulcers. Iron supplements may cause nausea and vomiting. Metformin, often prescribed for diabetes, may cause nausea or diarrhea. 

 What if I have diabetes? 

Special care must be taken if you have type 1 or type 2 diabetes or are taking diabetic medications. (Certain diabetes medications, such as metformin, are used for other conditions, such as polycystic ovary syndrome.) Monitor your blood sugar closely and adjust your medications accordingly. Close monitoring by your physician is mandatory. 

If you cannot be followed closely, do not fast. Fasting reduces blood sugar. If you continue taking the same dose of diabetes medications, especially insulin, during your fast, your blood sugar may become extremely low, resulting in hypoglycemia. This can be a life-threatening situation. You must take some sugar or juice to raise your blood sugar back to normal, even if it means you must stop your fast for that day. You must closely monitor your blood sugar during your fast. If you repeatedly have low blood sugar, it means that you are overmedicated, not that the fasting process is not working. 

Can I exercise while fasting? 

Many people assume it will be difficult to exercise while fasting, and sometimes those with physically demanding jobs worry about fasting while working. Yes, exercise demands extra energy from the body. However, the process of using stored food energy during a fast remains the same. 

The body starts by burning glycogen, the sugar stored in the liver. Since there is extra demand for energy during exercise, glycogen runs out sooner than otherwise. But your body generally carries enough glycogen for twenty-four hours, so it can sustain a fair amount of exercise before running out. However, endurance athletes, such as Ironman triathletes, marathoners, and ultra-marathoners, do occasionally “hit the wall.” 

Glycogen stores run out, leaving their muscles essentially running on empty. Perhaps there is no more indelible image of hitting the wall than the 1982 Ironman Triathlon, when American competitor Julie Moss crawled to the finish line, unable to even stand. But even when our glycogen runs out, we’re still carrying vast amounts of energy in the form of fat, and during fasting, our body switches from burning sugar to burning fat. 

Following a very low carbohydrate diet, or ketogenic diet, trains your body tissues to burn fat. Similarly, exercising in the fasted state trains your muscles to burn fat. Instead of relying on limited glycogen stores, you can use almost unlimited energy from your fat stores. Muscles adapt to use whatever energy source is available. 

When we deplete our glycogen through fasting, our muscles learn to become much more efficient at burning fat. The number of specialized fat-burning proteins is increased, and the breakdown of fat for energy is enhanced. After training in the fasted state, muscle fibers show increased available fat. All these are signs that the muscles are training to burn fat, not sugar. 

Does performance suffer? Not really. In one study, a three-and-a-half-day fast did not affect any measurements of athletic performance, including strength, anaerobic capacity, and aerobic endurance. However, during the period when you are adjusting to the change from burning sugar to burning fat, you may notice a decrease in your athletic performance. This lasts approximately two weeks. 

As you deplete the body of sugar, your muscles need time to adapt to using fat. Your energy, muscle strength, and overall exercise capacity will go down, but they will recover. This process is sometimes called keto-adaptation. Very low carb diets, ketogenic diets, and training in the fasted state may all have benefits in training your muscles to burn fat, but your muscles do need time to adapt.

4 thoughts on “Fast – day#13 / looking back ~

  1. Thanks Bill for the reminder that any task that looks difficult can be done a step at a time, one day at a time. Like the Camino who is a great teacher. Can’t believe that 8 years went already since your Camino!


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