So an opportunity came about where I didn’t have much in the way of plans this weekend just gone so at the last minute I decided to take part in a 60 hour fast. The plan was to finish my last meal at 8pm on the Friday night and start the fast around 9pm.
I was interested more in how fasting would make me feel in terms of health and mindset. I also decided that taking bloods at intervals during the fast, would provide some statistics later on.
So here’s a breakdown of the timeline…
|Hour Interval||Glucose (mmol/L)||Notes|
|Hours 1 – 16||Hour 1 Baseline 10pm (5.2)
Hour 12 9am (4.6)
Hour 15 Midday (5.2)
|For the first 16 hours I felt pretty good. I was taking on water regularly and I didn’t start to feel any dips in energy until around the 16 hour mark. No feelings of hunger either. I’ve done IF in the past so getting to 2pm without the need to take in food is no big deal for me.|
|Hours 17 – 21||Hour 21 6pm (4.6)||Energy dropped significantly, felt extremely tired and started to think non-stop about food, so decided to head to the gym to a) take my mind off the food craving b) Deplete all remaining glycogen c) get an endorphin rush from the exercise. Combination of cardio & strength training accounting for around 500Kcal. Felt pretty weak by the end of it which I guess was the point.|
|Hours 22 – 43||Hour 36 9am (5.0)||Around the 22nd hour I started to get headache that increased in intensity. I was hydrating regularly, urine was pretty clear so this to me felt like my body was switching to ketone production to fuel the body in the absence of calories. The headache remained right up to hour 41 before tailing off rapidly. Energy levels had increased a little and not really enough to take part in exercise so I chilled and watched the tennis.|
|Hours 44 – 56||Hours 46 7pm (4.3)||This was a fantastic period to be in. Energy increased exponentially and I felt amazing. Did some gardening and kept myself active. Interestingly, although I was thinking about food regularly, I didn’t feel hungry at all – quite surreal.|
|Hours 57 – 58||Woke up to a horrendous headache, urine was dark so this to me signified the lack of hydration during the sleep cycle. After waking up, drank around a pint of water and the headache quickly disappeared.|
|Hours 58 – 60||Hour 59 8am (3.8)||Took bloods fairly soon after waking and glucose was down to 3.8 mmol/L. Felt pretty good after the intense headache and ready to return to eating normally.|
‘Breaking the Fast’
3 Poached Eggs / Half an Avocado / Onions, Pepper & Mushrooms fried in a little Goats Butter and a Jazz Apple with a glass of water.
|Weight Loss (a drop from 81.8 – 79.9kg)
|Sleep Overnight 1
||Sleep Overnight 2
There were periods during the fast where I could have easily given in to the mental queues to eat, so I learned a lot about the feedback I was getting. I took to bed early on both the Saturday night and Sunday night and through sleep monitoring it became apparent my sleep was more consistent and deeper than usual. Period of low and high energy levels were anticipated, however energy levels towards the end of the fast went through the roof. A word on caffeine also; prior to the fast I was consuming around 6 cups of tea a day and a cup of coffee, so the early headaches I was getting may have been the lack of caffeine that was going into my system. Since the fast I’ve switched to water instead and I’ll feel so much better for it.
Happy to field any questions regarding the fast, just enter a comment in the box below and I’ll get back to you.