Combining alternate day fasting with HIIT is one of the best way

(Sorry, for my inevitable mistake in the language, I'm not a native. Feel free to correct me.)

I have an idea that combining alternate-day fasting with HIIT may help the body burn carbohydrates and enter ketosis faster.

The main concept of fasting is that it makes your body burn the reserved energy stored in your body which will burn the carbohydrates(glycogen in the liver and muscles) first until it's depleted, and then the fat which produces ketone body. The main benefit is that the ketone body can act as the cell signal which increases the longevity of cells in the DNA level(anti-aging), improves the brain cell plasticity(by signaling the neuron to release BDNF), decreases inflammation(faster healing), and improves immunity(prevent cancer and less sickness). The process of producing ketone body from fat burning is called Ketosis.

However, fasting in humans has a flaw. It takes much time to completely burn Carbs and gradually enter ketosis which needs more than 24 hours for the real intense benefits to occur after fasting(it needs 24 hours for anti-aging and 48 hours for plenty of BDNF in the brain). The one good solution is to eat only a ketogenic diet which is no carb eating but only protein and fat, resulting in the body using only fat as its main energy and staying in ketosis all the time. However, the Ketogenic diet is not always convenient or available to everyone. Thus, I have another idea which is to eat normal foods and use exercise to increase Carbs burning to enter ketosis faster.

I found that HIIT(High-intensity interval training) is an exercise that is very effective in burning calories even in the resting time after exercise. Also, HIIT itself can boost BDNF 4-5 folds of normal exercise even in exercising for only 5 minutes. And with its lesser-time usage, I think it is very suitable for combining with fasting.

The following are the ways I've done HIIT with alternate-day fasting

• Having 6-7 meals in the feeding day. Make sure that it is equal to the meals for 2 days and one HIIT exercise.
  • I don't fix the time limit for fasting(which may be around 12-16 hours). It is just like having a meal for every 2 hours in a feeding day.
  • Don't worry about eating too many carbs because the body has limited storage of carbs(only stored in the liver and muscles) and the excess will be changed to fat(which can be unlimitedly stored under the skin).
    • However, the fewer carbs you eat, the easier and faster for the body to enter ketosis, and the more benefit you get.
  • I found that limiting the feeding period to 12 hours is much more favorable than 16 hours because 16 hours of feeding means eating even before bedtime which will cause a tendency to sleep later or decrease in sleep quality and poorer health instead (I think 16-hour feeding is able to do but shouldn't be often.)
    • remember that people who eat less live longer, eat more live shorter. 
• On the morning of the fasting day, I will do HIIT exercise(don't forget to warm up first with the slow running for 3 mins) by alternating between splinting(fast and hard running) 100 meters and slow running 100 meters within 5 minutes.
  • the concept of HIIT is an intense cardio exercise but not a strength exercise which means that it requires the same weight but a lot more cadences to hugely increase oxygen usage.
    • The technique of fast running is to run like there is a tiger or a monster chasing you.
      • It produces a lot of huge breath, faster entering ketosis(burn fat) and my meditation is so much better(focus and calm).
    •  run with short steps (no need to take longer steps which will load more weight on joints and be more prone to injury) and focus on hugely increasing cadence(more frequent short steps), pushing as much as you can before your body needs to take a huge breath.
  • the real benefit of this type of exercise occurs when pushing yourself so hard enough that the body needs to pause and take a lot of huge breaths. The breaths have to be so hard that every word you want to say is separated by the huge breath which is a sign of less Oxygen in your blood(reaching VO2 max). The less oxygen in the bloodstream, the more BDNF will be released, and the more benefits you get.
  • However, you don't need to push yourself over your limit, just as hard as you can. Just do it in 5 minutes for a few huge breaths is enough, the goal is only to accelerate the burning of glycogen(Carb.) in the body.
  • After exercise, don't forget to drink some electrolyte water(1.5-2 teaspoons of salt, no sugar and make sure to spread evenly throughout the day) to replenish the loss caused by exercise and fasting. Also, don't forget to stretch the muscles after exercise.
    • normally, people need daily salt intake not to exceed 1/2-1 tsp but while fasting and exercising you will lose electrolytes more by the water that you drink which will bring sodium out in urine, and sweat from exercise.
    • If the body doesn't get enough electrolytes, the blood pressure will drop(hypotension), and you will feel weak and dizzy.
    • I found that taking 1 teaspoon of salt immediately after exercise prevents me from dizziness or feeling weak.
    • Another method, only when there is no salt available eg. going outside, is drinking no more than 500ml of water in the day. However, after exercise or when coming back home, there is still a crucial need to immediately replenish the electrolytes and plenty of water.
  • Physical activity during fasting: It is very easy to become cold when fasting because the body doesn't get heat from the digestion of food as usual, even exercising in the morning can't help this, so it is crucial to stay active by going for a walk every hour to make the body warmer.

Don't worry about muscle loss during fasting. There is an experiment that Fasting without body movement(sedative lifestyle) causes muscle loss instead of fat burning. But fasting with exercise or enough physical movement in daily life will cause very little muscle loss, in contrast, it sometimes even improves muscle strength and faster healing because of the anti-inflammatory effect of fasting.

• Also, I've tried doing HIIT on the feeding day, but no exercise on fasting resulting in weaker muscles, though there was enough replenishment of nutrients after exercise in the feeding day, especially plenty of proteins which implied that exercise on fasting day may be better.
• I also found that after doing HIIT, I can also do the strength trainings such as sit up and push up which will also help me burn the glycogen and enter ketosis faster.

P.S. There is research that doing HIIT alone has a lot of benefits for the body(release BDNF 4-5 fold). But I am curious about the duration of the effect may not be much long eg. 30 minutes to a few hours after exercise. Thus, combining HIIT with fasting can accelerate and boost the effect to be longer, richer, and more effective.