Fasting for 24 hours is hard work if you aren't used to it. When you've done it a few times it becomes a breeze. So if you really want to step up your fat burn it's time to up the game. Fasted High Intensity Interval Training (HIIT) could be the answer. I'm not going to tell you that it's easy. When you are fasted after about 18 hours your energy levels in terms of blood glycogen, will be low to none existent, so your body has to draw on other energy reserves, including fat stores, to get you through your training routine.
I won't cover off the benefits of Fasting or HIIT separately here, but I will mention a few of the benefits of combining both.
- The increased utilisation of fat stores is the primary reason for doing fasted HIIT. As the glycogen in your bloodstream and much of your liver stores is depleted after about 18 hours your body will increase the levels of fat it will use as energy. Furthermore, with HIIT training you get an additional post workout afterburn effect called Excess Post-exercise Oxygen Consumption (EPOC), which essentially means that you will continue to burn fat for up to 24 hours after training.
- With both Fasting and HIIT you get a significant increase in both Human Growth Hormone (HGH) and Testosterone (particularly if you use my martial arts HIIT routine here – https://steemit.com/health/@unclehermit/a-fantastic-martial-arts-hiit-training-routine-for-men). When you combine the two however you get a synergistic effect which boosts them beyond the levels that they would be if you did one or the other in isolation. HGH is often called the youth hormone because it promotes longevity and slows the effects of ageing.
- One of the major benefits that I have found when doing fasted HIIT is the rush of energy that I get afterwards. I feel awake, alive and vital. This runs counter to what you would think after not eating for 18 hours or so, but in reality your body can survive a lot longer without food. The feelings of hunger that we get after a short intermittent fast are not starvation, it is simply your body adjusting to low glycogen levels. Another hormone, Ghrelin, is then released into your body to tell you that you want food. Once you get used to this hunger feeling, you just learn to ignore and even enjoy it.
- It's time saving. If you can fast for 24 hours, you are essentially missing 2 meals. I prefer to fast by missing breakfast and lunch and then have my dinner at around 8pm. Missing breakfast and lunch saves a lot of time to focus on other things during the day. Additionally a HIIT routine can be completed in as little as 20 minutes, giving you improved benefits than you would get from an hour of steady state cardio (jogging etc.) So if you have a hectic lifestyle and little time then fasted HIIT is definitely for you.
A note of caution. Fasted HIIT is not for beginners. You need to build up and have a reasonable foundation level of fitness before you attempt it.
Further information:
- https://www.muscleforlife.com/fasted-cardio/
- http://fitness.mercola.com/sites/fitness/archive/2014/09/26/intermittent-fasting-hiit-workout.aspx
- http://www.livestrong.com/article/477830-how-long-does-glucose-last-when-working-out/
- https://greatist.com/fitness/afterburn-effect-keep-burning-calories-after-workout