5 Day water fast. 120 Hours with zero calories.

9 min readMay 24, 2020


My name is Juan Calle, I am a 32-year-old male living in Atlanta, Ga. I got interested in fasting a few years back from listening to the Ben Greenfield Fitness Podcast, initially starting to dive into these experiences for the fitness and physical benefits.

For my career I am a serial entrepreneur and I currently own and operate a couple of restaurants and do real estate investments on the side. For my free time I compete in Ironman Triathlons and spend anywhere between 12–20 hours per week training to compete at a high level.

As many of us do, I started with intermittent fasting on a weekly basis and increased to have one 24 hours fast per week. I was very intrigued by the concept of “train low, race high”, which is a highly debated concept for training for endurance sports. This consists of doing some of your training on a fasted state with lower glycogen storage, preferably those sessions under 60 minutes, in order to teach your body how to use fats as energy source during these training sessions. A couple of years ago I did a 3-day fast and had an amazing experience.

A great source for fasting is the book The Complete Guide to Fasting by Jason Fung, I used this when I started fasting to really understand the science behind it and how to best practice fasting.

Key benefits that I found from a 5 day fast.

· Increased mental clarity

· Increased spiritual connection

· Increased creativity

· Reset eating habits

· Clarity with my relationship with foods

· Reset of morning routine

· Reset pallet to introduce more vegetables to my diet

· Cravings for more nutrient dense foods

· Increased energy and positivity

Reasons why I chose to do a 5 day water fast

· Longevity- cellular regeneration

· Gut health

· Reduction of plaque buildup for better cardiovascular performance

· Increase in growth hormones and stem cell production for recovery from long training blocks

· Lower inflammation

· Cancer prevention

· Mental and Spiritual cleanse

· Reset eating habits

Supplements and mindfulness practice

For my fast I decided I would only supplement with a daily multivitamin, a gut health supplement (this supplement is great for fixing leaky gut and improving your gut-brain barrier), fish oil, and melatonin for sleep as necessary (I only took this days 1–3). In addition, I would drink coffee as needed up to 3 cups per day.

Each day I did 10–20 minutes of meditation, including some gratitude meditation using my Thai mala beads (I find this is a great tool to keep me engaged in my gratitude practice when I have a mental block). I used my 5 minute journal daily as well.

I had a mantra for my entire fast, which is something I never practiced before and I think it was of great help. My mantra was: I will always stay positive, which I also used as my daily affirmation during my morning routine. In the evenings when I was having trouble sleeping, I used visualization, which I find very helpful when facing challenges in my life. The combination of a positive mantra, daily affirmation, and positive visualization really helped me to keep a super positive attitude during this entire experience.

Day 1

I started my fast on Sunday at 2 pm. Before the fast I ate a larger than average breakfast with some eggs, chicken, and some sautéed veggies. For lunch right before my fast, I ate a fruit bowl with a smoothie base of coconut milk and açai, topped with a little granola and a mixture of chopped fresh fruit.

When I started, I weighted 154 lbs. I am pretty lean at that weight and I am 6 ft tall. Not exactly sure what my body fat percentage is but I believe its between 8–12%.

Day 1 as usual was pretty easy for me, as I often do 24-hour fasts. It became easier since I knew the finish line was far away. During this day I rode my bike at a low intensity level for 50 minutes.

I supplemented with Melatonin because I knew sleeping would decrease as the fast got longer and my body up-regulated adrenaline and growth hormones production.

I used The Whoop Strap to track my sleep, recovery, activity and HRV (hear rate variability).

After day 1 I slept almost 9 hours, did not set an alarm, and my HRV was the highest it has been all year at 198.

Day 2

I woke up and ran a couple of miles at a moderate pace and intensity. It felt okay but I was starting to feel my heart rate spiking up faster during some hills, this is typical for prolonged exercise during fasted state.

During this day I started to feel an increase in mental clarity and energy. At this point I believe I was in Ketosis.

I had a gratitude meditation practice with my mala beads and found an increase in my mind to spirit connection. I was able to pull back memories from my childhood and from previous stages of my life that helped to form me as a person and relive them while being grateful for them.

During lunch time I had some moments of irritability, which came and went within 20 minutes or so.

In the evening I had some cravings so I made a tea as my wife had our siblings over for wine night with some delicious snacks that I could not touch.

My sleep started to decrease as my adrenaline levels increased.

My total sleep dropped to 6 hours, and my HRV was at 69, it is usually between 90–140 during days when I have these levels of activity. Total calories burned that day was around 3,000

Day 3

During this entire fast my team and I were in the process of re-opening up our Spanish tapas restaurant Buena Vida from being temporarily shut down from the COVID-19 pandemic. Initially it may seem as if this would make it more difficult because I would have to be around delicious food the entire time, but it was actually very beneficial because if kept me busy and engaged, which took my mind away from cravings.

During this day I finally noticed that my digestive system was fully at rest, there was no more gut activity, which allowed for my body to shift some of that energy into ketone production, increasing mental clarity. My sense of smell became increasingly sensitive, and I was able to do some clear visualization and applied that practice to some aspects of my career.

The night of day 3 was the hardest for food craving. I woke up in the middle of the night and the only thing I could think of was the flavors of different foods. It was not a hunger craving, but a craving of food and the dopamine release it triggers in my brain. I believe it was also more challenging because I knew that I was entering into uncharted territory as I had never done more than a 3-day fast.

These cravings allowed me to solidify that I need to view my relationship with food in a different way, in order to continue to improve my health.

My sleep continues to decrease to under 6 hours, my HRV was a bit lower at a 62. My resting heart rate stayed pretty consistent the entire time in the low 40s. Calories burned 2,600

Day 4

Day 4 was a great day. Much of the literature I have read says that day 4 is when cravings and hunger subside, brain function continues to increase, and overall sense of well-being increases.

I am happy to say that all of those things happened.

Sometime this day my digestive system completely slowed down. I could feel basically no activity in my intestines, which I believe is part of the reason why cravings and hunger totally went away.

My meditation this morning was engaging, and I felt a strong body and mind connection. I started to notice that my muscles were pretty depleted after my morning workout. I did a very light body weight strength routine of 20 push ups, 10 air squats, 20 swim pull cords 3X, and noticed that if I went much longer my legs may start to feel fatigued.

This was the first day that I noticed a significant drop in body temp, and I needed to wear a pullover to stay comfortable. Mood increased and I was able to have some very positive conversation with my family about the experience.

This was the first day that I really noticed a larger drop in my insulin levels, so I was careful to not stand up too fast, and to keep physical strain to a minimum.

During the night I felt similar mental clarity to my third day during my last 3-day fast, it was almost as if a part of my brain that is rarely fully engaged, was connected to my intuition, and it gave me new levels of creativity and optimism towards the future.

My sleep continued to decrease to under 5 hours, my HRV stayed pretty consistent at 68.

Calories burned 2,600

Day 5

Food cravings and hunger completely went away. My sense of smell continued to increase, mental clarity increasing. Insulin levels seem to continue to decrease. My energy levels are a bit lower than previous days, which I contribute to sleeping 4:45 hrs the previous night. I am starting to plan my re-feed strategy.

Kept physical activity to a minimum today and did not do any exercise.

Towards the last 5 hours of my 5 day fast my mental energy increase significantly. I was able to work on some personal development items that I was putting off. These include updating my personal mission statement, re-defining some of my core values and setting some short term adjusted goals to reflect the new realities with COVID-19.

Sleep increased back up to over 8 hours.

HRV increased to high 70s.

Calories burned 2,400

Final weigh in was 146.5 lbs.

Total weight lost: 7.5 Lb. I suspect 60% of that was fat, the rest was muscle. I will be back to my normal body weight in 3 weeks or so after properly re-feeding.


Open up with a glass of Athletic Greens.

Follow this up with a leafy salad with kale, mixed greens, 4 oz of salmon, half avocado, organic coconut flakes, raisins, cucumbers, Spanish olive oil, broccoli and hummus.

I am choosing to re-feed mostly on vegetables to take advantage of my pallet reset. I am hopeful that this allows me to enjoy vegetables more than I currently do and increase my craving for those nutrients.

Over the past year I have decreased my animal meat consumption to about 4 meals per week on average, and I have seen huge improvements in my fitness levels since this change.

Supplemented with CBD to relax and sleep better. My go to CBD is the Calm Charlottes Web gummies. I have tried many different versions and their formula really helps to calm down my mind and sleep better at night

Day 6 (after re-feed)

Weight was back up to 151 after some large re-feeding sessions.


Greens smoothie with a base of kale, celery, pineapple, spinach, lime, parsley, 4 oz coconut milk, coconut oil, protein powder, organic cacao, coconut flakes, banana, strawberries.

Swam around 2000 yards open water at a nearby lake.

Biked around 50 miles with some friends at moderate effort.

After a good night of sleep and replenishing my glycogen from re-feeding my energy levels continue to be above average. My workouts today after a 5-day water fast were strong, and my mood has been above average.

I have read literature that says growth hormone is up-regulated for the following 3 days after a fast this length. From my experience in today’s workouts, my mood and my energy, I believe this to be true.


It came as a surprise to me that a 5-day fast is much less challenging than initially anticipated. My experience from my previous 3-day fast was vastly different. I knew going into it that when the hunger came, it was a mental trigger and my body was perfectly fine and able to continue daily functions. This gave me the confidence to acknowledge my feelings and thoughts, and let them pass, much like a meditation practice.

Going into the fast with specific intentions and practicing mindfulness, meditation and gratitude were of great value. I believe this allowed me to set up my day in a way that would give me the highest changes of dealing with the challenges.

I was prepared to have to battle some pretty serious doubt during some of these days, however I never encountered any of these challenges, and never really considered not finishing it, or doubted the reasons for doing it.

If you are interested in doing a prolonged fast, I encourage you to read up on some literature, and start the process to train your body to be able to accomplish the challenge. It is a great tool to have in your toolbox, the health benefits are obvious, and the mental confidence boost can be very rewarding.


I am happy to say that my supportive wife and both of my parents decided to join me for the last 24 hours of my fast. It feels great to encourage others to join me in my quest for better health.