Training discussion with "Lover of Mountains" Kilian Jornet 

I, too, am a metabolic flexibility adherent. I do almost every run outside of a “race specific block” fasted and all the easy runs inside the race specific block are fasted. I’ll even end a day of fasting with a workout to really force the body into the fat burn. Totally tracking you here.

Same here. It's what you've eaten in the previous days that matters. I've started to do a high protein keto style diet 5 days a week then 2 days high carb around my harder days. I always feel best the day before a carb load but I always panic! 😂. My resting HR comes down and HRV goes up when I'm keto! I just recover much better without carbs.

I've probably seen more interviews of him in the last year or two then in 10 years before lol. Maybe the launch of his company demands it, or maybe fatherhood(and his new schedule) just mellowed him out a bit.

One GUESS is that you have made some fundamental changes in your intensity distribution and your entire HR range has expanded. I have athletes tell me that when they started getting their balance right on intensity and recovering, their maximal HR went UP. So, this could also result in higher sub max values, even though you feel fitter and better. The difference in metabolic efficiency breaking down fat and CHO is not large enough to explain a 10 bpm increase in HR at a given workload.

@@sportscientist Thanks so much for the reply. Your approach led me to a complete training overhaul. And recently I've been largely (80-90%) focused just beneath LT1. Gradually increasing power (bike) and lowering cardiac drift. Then, I started listening to guys like Kilian and Zach Bitter and went low carb. As I said, my HR (at the same pre LCHF pace) jumped considerably BUT (and I failed to menion this) my cardiac drift dropped substantially. And in fact, at the same pre LCHF power, I have been able to maintain a steady HR for almost double the length of time. I was thinking of dropping the power to beneath what I had thought was my LT1 HR. But I think I'll just crack on with the same power, accept a higher HR and assume I am below LT1 still. And it will be interesting to see if my HR has increased when I next take on an all-effort workout. Thanks for all the free help you give us all...!

I've had a huge bump also. Especially at my max heartrate. Training a littlebit less and doing only one fast, one long and rest easy / week has been the key for me. I think I was overtrained and for that reason my max HR was 15 bpm lower then it is now.

It's the opposite for me, when I'm keto and fasted my z2 HR is lower for the same power on a bike.

I am not Stephen, but it’s likely because Kilian’s competitions are so long in duration and therefore are at a relatively low percentage of his vo2 max so his ‘top end’ aerobic endurance is not that important. This is quite opposite to Niels whose competitions are much shorter in duration but at a much higher intensity

Pretty sure you'd need to go to a lab treadmill test to give you that kind of info.

We are working on a project related to quantifying ventilation in the field during training with a new wearable, so that will be interesting to get Kilian's unique insights there.

Thanks Stephen, hush hush, I won't tell a soul.

My impression is that he is not doing any very specific dietary strategy to emphasize fat intake. He is a vegetarian though.