If you work your muscles at enough of an intensity for at least 90 seconds before they fail, all three types of muscle fibers will be called upon to do the work. Once all of these muscle fibers are called on to work, it causes a chemical cascade in the muscle which dumps the stored sugar/glycogen, which in turn increases not only the muscle's size and strength, but also its insulin sensitivity and fat burning potential.



At that point, the causes of why we get fat are being reversed, glycogen tanks are less full, muscle cells become very sensitive to insulin, insulin levels drop, and fat is released from the fat cells so it can burned for fuel. Now the process of good health and weight is going in the right direction.

Increasing Fat is not going to help you in HIIT. At higher intensity your body needs energy fast, which fats can't provide. HIIT+Low carb is not something you would want to do. The muscles will start using lactic acid ATP for fuel and it often means Hydrogen in your muscles. Choose between carbs or not doing HIIT. If you do try, post your experience.

Increasing Fat is not going to help you in HIIT. At higher intensity your body needs energy fast, which fats can't provide. HIIT+Low carb is not something you would want to do. The muscles will start using lactic acid ATP for fuel and it often means Hydrogen in your muscles. Choose between carbs or not doing HIIT. If you do try, post your experience.

Wait, wut. Can you provide sources for that, Fattyman? Because everything I've ever found states quite the opposite.

Carnivor0us has it right that a small amount of carbs a half hour to hour beforehand helps sprinting ability and "burst mode" fast twitch muscle fiber, but anyone absolutely CAN do HIIT and tabatas and stuff in ketosis. Take a couple spoonfuls of unrefined virgin coconut oil before you hit the gym, it's a quick-releasing energy source that your body can use very efficiently for sustained periods.

Yes, generally, carbs are meant for vigorous workouts (sprints, heavy lifts) while fats are recommended for sustained low-intensity labor (marathons, swimming), and I understand where Fattyman is coming from regarding the carby anaerobic ATP production versus the fatty aerobic ATP cycle, but if you are fully fat-adapted, your body actually becomes really good at continuing the Krebs Cycle (anaerobic ATP production) using molecules gained from tearing apart body fat as a substrate instead of using glucose.

It's pretty much the entire point of the keto diet, to be honest. It's why we have steady levels of blood sugar even if we haven't eaten anything in 3 days and only had a couple pounds of rare veal during the week before that. Humans evolved to produce and thrive off of ketone bodies in the absence of glucose.

http://www.youtube.com/watch?v=NqwvcrA7oe8

Hello, I would like to share my experience in regards to this topic..

I have been doing Circuit Trainings (Jillian Michaels'- which go upto 55-60mins) and then 30mins of cross-country training program on Elliptical. I use FTR4 to track my HR and calories burnt. When i started Keto (actually inspired by atkins first) i weighed 95kgs (~209lbs) and in around 3weeks (doing keto at 21g net carb intake and the aforementioned trainings) i weigh down to 88kgs (~194)

I would feel dizzy (little) and tired after my workout. Completing my 90mins training at gym would take real efforts (maintaining my HR between 155 and 175). Since Monday i started taking a pre-workout drink (greek yougurt+almond milk+dried cranberries+dried raisins+banana) 30-60mins before my workout. After trying this for 3days, I didn't feel dizzy and my workouts would get completed easily. Plus, I would still feel active (instead tired) at the end of workout.

I find it helpful to have a pre-workout good carb drink so that I can use it for my workout and not affect my overall net carb intake. However, mfp does not sees it this way. It counts the carb intake of my pre-workout drink but my friend asked me not to count pre-workout carb drink as those will get consumed during my workout.


Your suggestions/comments are welcome to let me know if I'm on right track or doing something wrong.

I do HIIT style exercises once or twice a week with with a personal trainer and it's pretty much a non-issue for me. I eat my regular keto diet, when I need more calories for any of my exercise, I eat more fat, as usual. I actually last through these exercises better than my husband, who is on a regular high carb diet. I've been on keto since July 2013 and exercising with my trainer since December 2012. I also do long running (half marathons) and Hot Yoga.

I think the thing you have do is always a N=1 test - just try it, and see how it goes for you. Everyone's body chemistry is different and you just won't know how you'll do until you try it.