I've heard that HIIT brings some people to a deeper ketosis. I've hit my stride and can do either intense short or moderate long exercise, moderate exercise doens't seem to do anything one way or another. HIIT makes me have keto breath the next day.

Professor Tim Noakes is a wonderful guy to listen to about exercise and ketosis/LCHF. He's in his 60s and still runs marathons (and I believe ultra-marathons too). He wrote a book years ago saying marathoners need to carb up before running. He now starts his talks by telling everyone how totally wrong he was. He states facts about current ultra-marathoners, ironmen etc who are outperforming their younger selves because they are now on a keto/LCHF diet. He does very short podcasts through talkfeed.co.za/lchfpodcast/ and on one of those he mentioned that keto/LCHF athletes really came into their own and performed at their best for the middle and end of races when glycogen-dependent athletes had hit the wall. The LCHF athletes just kept powering through and, if anything, were stronger as the race progressed. He runs marathons in a fasted state, taking in only water and a little fat during the race. YouTube has many, many interviews and presentations that he's given around the world and he has a really easy-listening style, but is very authoritative.

For myself, a 58 year old overweight woman, I go on a treadmill for around 35 minutes 2 or 3 times a week. I play a video with music and alternate walking one song, jogging one song until I've jogged 4 times, then I alternate sprinting flat out, and walking a couple of times before I cool down. I do know that I was an idiot keeping up my exercise while I keto adapted. Admittedly it was mid-summer and very hot, but I was so breathless walking even short distances outdoors during that time and ended up with heart palpitations and all sorts of interesting things. I took a couple of weeks break and am now back to prior health/fitness/performance. It's too early yet to say if I will gain additional fitness.

As far as there being such a huge range of conflicting ideas, I got confused by all of that for a while and then decided to just pin my trust on one person and got with that until I knew what my own experience was.

wabmester wrote: »

Intense exercise needs glucose....

While technically true, the body's definition of "intense" changes with keto-adaptation and time.

In Dr. Peter Attia's case, his aerobic base (the point at which you start burning 50% of your fuel from glycogen) had double the VO2 capacity. The glycogen requirements for his marathon pace went from 95% (needed nearly all glycogen) to 22% (used more than 3/4 fat).

In other words, he needed less glycogen (glucose) for the same activities at the same intensities after he was keto-adapted than before. However, he did have to sacrifice a little top end (VO2 max) in order to get these other results, which does suggest that if you want all out power for a 100m sprint or some such (where you would be well into glucose burning territory and are basically like a street racer burning NOS), then a carb-up might be a good idea.

http://eatingacademy.com/how-a-low-carb-diet-affected-my-athletic-performance

leonidas_and_spartacus wrote: »

Glucogenesis is slower and can't provide energy at high intensities.

I've read that the GNG happens at rest to restore glycogen, but I'd like to learn more about the alternate pathways. Especially since I just got back from lifting weights, and my butt is kicked.

My (limited) understanding is that being thoroughly fat adapted (nutritional ketosis) is great for endurance, but not as important for short explosive exercises.