Response to 'High-Fat Diets Still Don't Boost Endurance'

The article "High-Fat Diets Still Don't Boost Endurance" written by Alex Hutchinson in Outside Magazine discusses how low carb high fat diets still doesn't work has been sent to me several times over the past week with many beginner triathletes still confused about whether they should be keto, lchf, or use carbohydrates in their triathlon training.

In this video Taren discusses the opposing viewpoint to this article explaining how several studies have proven that Ironman athletes perform better with a high fat oxidation rate, how Dr. Dan Plews has shown a very low carbohydrate (keto) approach actually improves power, and how the current studies has a number of errors in their discussion.

[jc]

I don’t understand how you can claim you are having “success” with lchf if by your own admission you are overtrained and having your body and performance regress substancialy in the last year on that diet.

[mrrpgswe]

Nice to see the low carb heritage of people like Tim Noakes and Jeff Volek becoming the gold standard across the board.
Nice vid 🎉🎉🎉🎉🎉

[forwardmotionenthusiast]

LCHF has been a game changer for me ever since we talked about it on the Zoom trainiac meet up. I’m honestly not sure how my fat oxidation compares, but I feel so much better, dropped #25 and starting to get faster on the bike and the run and have had zero blood sugar issues. Thank you for defending this. I think a lot of coaches and athletes think carbs make the world turn, which for some it may. But it’s great to hear that there are other ways to be nutritionally successful. Thanks for all you do Taren!

[VanLifeTriathlon]

Watching this as I eat my pre-workout oatmeal and waiting for the trolls to start commenting 👀

[MattFenlon]

Went on a 50k tempo ride yesterday after a 24hr fast (been keto for a while), followed by a 20min brick run. PR'ed. Felt great, no bonk. Didn't even feel hungry after; ate because I knew I should. Not saying it will work for everyone as everyone's body is different, but fat adaptation has been great for my training.

[MarmaladeINFP]

There is a difference that makes a difference. On a high-carb diet, one is not fat-adapted and so has little access to burning fat. And, so, one is reliant on an endless supply of glucose. But n a keto diet, one is dual-fueled with an ability to use both glucose and ketones, even simultaneously. During endurance or high-intensity exercise, someone already in ketosis and fat-adapted can also use glucose at the same time.

A metabolically fit athlete can consume a surprising amount of carbs during exercise while remaining in ketosis. Also, keep in mind that the body can produce it's own glucose from fat, protein, and lactic acid. This is all the more reason a keto athlete should eat plenty of fatty animal foods prior to any major training or competition.

[ChristopherHague]

Did you read Burke’s study? She actually addressed your issue with the on boarding process. She also had three groups in the study: keto, LCHF, and HC

[mtnbikehead]

Sweet Spot, love the pun!! This has been my approach.
Keto is fine in the off-season. Up the carbs depending on the activity.
Stay metabolically flexible.
I hardly ate anything but electrolytes on a 140 km ride on a really hot sunny day. I felt great at the end.

Excellent vid Taren!!

[trbeyond]

I enjoyed 150g carbohydrates just while watching this video.

[jeffreymarkle]

I spent this past year converting to low carb. Did full on keto for about 4 months then low carb healthy fat at through spring and summer. My IM was canceled so I did it virtually this past Saturday. Took in less than 60 grams of carbs per hour. Never bonked No gi issues of any kind and felt good the entire way. I’m a 56 year old male endurance athlete my entire life and this system worked great for me. I haven’t felt this good in years The virtual IM went great and felt great. It works!

[seanchin]

Kipchoge is HCLF. End of discussion bruh.

[neillgowans]

I like you Taren but you’re always focussing on the quick fix thinking you’re using science based marginal gains. Dan Plews may be a guru but he will be the first to say he doesn’t have answers to go with his PhD. I have an MSc in Sport Science and I certainly don’t. We’re all different of course but there is nothing really new out there if you want stay natural (research mainly confirms what successful coaches know works already). Some people will do well on low carbs most people won’t whether for racing, big works or recovery. Get more sleep, follow a progressive training plan, eat well and go at it with legal technology to how ever high your budget will let you.

[bighammer]

Your calorie numbers don’t make sense. You are assuming that non fat adapted athletes get 0 calories from fat which is simply not true

[enxxmp]

In most people 3.5 weeks isn't long enough to become fully fat adapted. At least that what I've read in some studies on the matter.

I commented before I got to the part where he states what I said.

[tonykonvalin]

Good stuff - I actually mentioned to Alex that he incorrectly equated Keto to LCHF and he agreed they were not the same and apologized. He did say there were LCHF people in the test but I did not see any macros for them so have no idea what LCHF means for the people in the test. I have been LCHF for over 3 years and along with controlling weight without watching calories - I actually do not count carbs either as go by what I feel - and do just fine on long rides and shorter harder ones. One other issue I find is that when one looks at high end athletes they at what ares still shorter races, yes a marathoner that does a 2:10 is still out there a relatively short time, with a HR that probably nudges them to the limit of their cross over. IT has been found that even HCLF people can better their fat burning but there are limits and for the endurance athlete where it is about more time burning calories the LCHF approach comes more into play. None of this deal at all with the overall health benefits of a LCHF diet, I am not talking KETO even some would argue Keto is healthier, which is probably even more important.

I have these conversations over and over and talk to many in the HCLF realm and they say we need to do better studies - well there have been quite a few studies, such as the FASTER Study but the truth is there is little money out there for these studies as there is little to be gained by the Sports Carb industry so why are they going to spend the money. And as I think it was Volek who said - may have been someone else - it is hard to get a carb guy to transfer over if they have sponsors as their performance may indeed go down for a time and then if one of their sponsors is a carb company there is that issue. Then again Jeff Browning who is a LCHF guy who uses strategic carbs when racing has Gu as a sponsor.

Bottom line is all too often the tests done are done to disprove something and in the desire to do that often the direction the tests fo accomplishes that. Burke who did this study, I think, had been criticized the first time that there was not enough time to transition but even in this study there was not enough time. Yes one may transition some in a few months but if one is like me it has taken a few yers of tinkering to figure out what is best.

Thanks again for the video.

[zacsborntorunrunningadvent]

Famous Mark Allen had great success with highfat & Zone2 type training. Max Aerobic Function. From memory he went from 9min miles with Dr Phil Maffetone... and ended up superbly fat adapted to the tune of 6min miles at the same topeend zone2 (for example 150bpm). Always fascinating. Cheers

[HughDWallace]

Good stuff! Would you be able to post up links to all the articles you refer to, please?

[EnduLover]

In my experience as a Long distance triathlete I have always had a Low carb approach as I became more trained and I was doing great. I ran 2 hours without problems, and my performances increased. Now with the change of mentality I am taking in more carbohydrates and I have continuous drops in energy, continuous hunger and I have to load up on gels before each outing. I think the optimum remains Train Low Race High, therefore Low Carbo periodized with pre-race recharging

[robinmacandrew]

One of your best mate. So you’re training LCHF but then how do you fuel for races to ensure you’re carrying enough carbs without restricting fat utilization?

[spunkwater]

I appreciate your more balanced take on LCHF training. While I don't know LCHF is something I will try, I agree fully there is a lot of middle ground between Keto and all carbs/all the time.

One piece of nuance that was't mentioned was the importance of carbs during high intensity training sessions. As you stated, studies have demonstrated depleted glycogen stores will inhibit our top end performance. While we may not need top end speed on race day, most triathletes will have 1-3 high intensity sessions a week and almost certainly wouldn't get as much out of them as they could if not properly fueled. The same researchers suggest it can be helpful to have one or two carb-depleted sessions per week as long as you are working in low intensity for the same reason - you are fueling for your workout and, indeed, wanting to increase your body's fat-oxidation abilities.


No matter what any study says, we are ultimately an N of 1. LCHF may work extremely well for some individuals, and it is important to know what works for you and why. And, as you say, there is a lot of middle ground on what a LCHF diet is - I would contend there is a lot of middle ground on how low carb nutrition can be applied to training.