Distance Running on Keto


I ran a half in May (Keto since October) and ran the race fasted. I find Keto is a big simplifier of fueling. I am not thin so have lots of body fat to burn. I do almost all of my runs fasted and it hasn’t posed an issue. I’ve read about others using generation UCan on Keto as fuel and might eventually give it a try. They are sponsoring the next half I’m running in October and so I may give it a go at the aid stations (with a trial before the race) but this is just for experimentation rather than out of need.
Good luck!

(Carol Hawkins) #22

I ran a half last week fasted and got an 8 minute PR. Much easier to run with less weight! :running_man:

(Carpe salata!) #23

I ran for the bus . It was ok, I caught it.

(Lisa Chamberlain) #24

Hi I’m new to keto, I have been on this for 6 weeks now & really noticed a difference in my energy & focus, the first two weeks were hell craving all my sweet things biscuits fruit etc, anyway now I don’t miss them at all, I look forward to making my meals, I am running my first London marathon next year so thought I would try this plan, I have ran a few halfs before but struggled, now already running easy 14miles & still feel I could carry on but won’t push it to quick, I am 47 & been running for 3 years now but never this far, once you know what you can eat & get your head round it I feel it has benefited me already, anyone doing the London marathon see you there, I’m running for SENSE the deaf & blind so if you feel you would like to donate for my charity I would be so grateful £1 even would make a difference!! Lisa chamberlain5 on justgiving page, if you do donate please leave a message so I can thank you.x



(Kerianne Wurfel) #26

So how did it go? I’m planning to run my first in March and would love your input on keto vs carb fueled. I’m LCHF (go in and out of keto), and have been running for a while. I usually don’t eat before a run, but was having half a fruit before longer runs over the summer, not so much lately… I’d really like to get fully keto adapted to run this marathon, but would love your thoughts since you’ve run marathons on carbs and keto.

(Daniel Schroeder) #27

I thought I’d share my experience running and the change that going keto has brought to my training, preparation and results (so far).

I’ve been running since high school X Country (I’m currently 38) and always subscribed to the premise that carbs were essential for fueling my activity. I’ve run at least 20 half marathons and started running marathons in 2015, still pre-keto. I trained extensively for both marathons but had similar, disappointing results. I ate GUs and drank Gatorade, but my body shut down anyway. In both marathons I bonked around mile 22 and dragged myself across the finish. I started keto as a tool to try and eliminate bonking but it has impacted my life in much more lasting and significant ways than just changing my body’s fuel source. It took me a solid two months to feel really fat adapted and while my body was making that change, my running performance and energy for longer distances suffered a little bit. This past November I ran my first half marathon since making the change to keto and really didn’t know what to expect. The results were enlightening. I’ve run the same race on three previous occasions. It’s a very flat, very friendly course and in 2016 I ran my best ever half marathon time on it (1:39.45). During the 2016 race, I stuck with a pacer and willed myself to finish the last two miles. I was exhausted afterward and sore for days but happy with my time. This past November, I had no idea what was going to happen and figured that there was a pretty good chance that I’d end up walking a significant portion of the race. I hadn’t trained as well for the race as I had the year before. Also, the night before the race, my dog was sick and I barely slept. On the morning of the race I didn’t eat anything; I simply drank water. I started out following the same pacer as the year before, figuring that I’d keep up for as long as I was able. At about 5 miles in I felt tired but in a strange way but continued on. By the time I was at mile 13, I felt pretty much the same as I had when I started the race. I passed the pacer and pushed myself toward the finish, breaking my previous record by more than a minute. After the race I wasn’t hungry and didn’t eat until dinner time later that evening. My body wasn’t nearly as sore in the days after the race. I realized after the race that I could have run faster. I definitely could have run farther I suspect that the strange tiredness I felt at mile 5 was due to a change i n perceived exertion.

I’m training for another marathon, this time strictly as a fat adapted athlete and can’t wait to see what will happen. I plan to focus on hydration with more intention for my next marathon and don’t plan to eat anything before or during the race. I’m a believer in the efficacy of fat as a fuel source for endurance activities and that glucose does significant harm to our bodies, inhibiting recovery and limiting our ability to push our limits.

(Jay Erdahl) #28

I’ve been a fat-adapted ultra marathoner for the past three years, running 3 marathons, 2 50ks, 1 50 miler and a 100 miler along with lots of races from 1 milers to half marathons around the big runs.

I’ve dropped my marathon time from 4:30 to 3:30, and am actively trying to qualify for Boston.

All while sticking to keto.

All of my training runs are done completely fasted, regardless of whether they are 3 miles or 30.

I am a big believer in building up my glycogen stores in the 4 days before the big races, which is the only time I drop out of keto, but do that “carb loading” through eating non-starch veggies - 100g per day of them for 4 days but nothing within 24 hours of the race.

I don’t eat or drink anything before any race that’s less than a marathon. For marathons and beyond I take a gel made of Generation UCan, coconut oil and water before the race, as well as every hour during the race. This has worked well, with (2) exceptions:

  1. During the 100 mile race the temps spiked above 95, and I couldn’t keep the gels down. I just stopped eating food and ran the last 15 hours on body fat.
  2. I’ve noticed a lack of energy as my speed has increased. I’m playing around with exogenous ketones - you can see the results of my attempts in a different thread in this forum - Exogenous Ketones in Marathon Running

Water? Yeah, no, not if I can help it. Just drink a decent amount in the days leading up to the event, and eat enough salt to aid in water retention.

(Will Madams) #29

I’ve completed a marathon, 3 half marathons and 1x50km trail run keto. half i run with no food at all just water at stations (running in australian summer) for the marathon i took a handful of macadamias salted. Anything over 20km runs i usually take the salted macadamias with pumkin seeds salted and coated in 90% choc.

I have experimented with have a class of water with chia seeds coconut oil a squeeze of lime. (sometimes with a little truvia) similar to a drink recommended in the book Born to Run,

(Julie ) #30

Hello, I am a competitive walker and do mostly half marathons. I am doing one in about 6 weeks and started Keto in January. It normally takes 3 or so hours to walk a half and would like to know if I need to do any particular items for as nutrition. Pre-race, during and after? Look forward to any advise and suggestions.

(David) #31

It doesn’t matter how much sleep you get he night before a race which is good because of the early wake up. It’s the night before that that is critical. So a good night’s sleep on Thursday night for a Saturday race is what counts.

(David) #32

I’m a few days into keto and a few years into plantar fasciitis recovery. On a run last week, it hit me that instead of going back to endurance, I should run my first road race… a 5K. I started running 4 years ago and jumped straight to ultras (couch to 50K in about a year) so I never found Speed. I’d like to meet him.

I’m still figuring out how to fuel my life so fueling my runs is more challenging. I hadn’t heard about fasted runs so I’ll look into that.

I’ve been using Maffetone’s heart rate training on and off for a few years. He writes about combining it with keto and speeding up gradually. From where I’m starting and where I want to go, I might make it by the time I die running only aerobicly.

My question: Are keto/LCHF runners going at an aerobic pace for races or venturing anaerobic? I tried a speed workout and I. Was. So. Hungry!

(ianrobo) #33

sleep before an event, what the jolly fun is that ??? Something I have not heard of !

(Jay Erdahl) #34

Maffetone is amazing - I’ve been an avid follower of his since hearing him on Endurance Planet several years ago. Having listened to him, and read his stuff, I can say with confidence that aerobic and anaerobic are both part of what he recommends.

It depends on what your goals are. The first part that he (and I) would recommend is getting a HR monitor and doing all of your runs below your MAF score - which is a formula that Dr. Maffetone developed over years of helping runners improve. It’s roughly your anaerobic threshold, but takes into account a lot of other factors, such as medicine and how new you are to running.

The second part is a 3-month induction period where you run nothing but below MAF. This is where most people jump off the program - they want to run fast. The key to the three months is that you develop an amazing ability to burn fat while running. You don’t have any choice - you’re keto, so you have low glycogen stores and there’s none of that pesky glucose floating around. The only thing that’s left is good old fat, and a bit of injected protein. You get really good, and you improve. Wow, do you improve.

Also, after that 3-month period, you can start working in sprint work and intervals, running above MAF, as you prepare for specific races.

I did my first 3-month induction period in 2015. I ran my first Tough Mudder (half marathon obstacle course), my first 50k and ran a 4:30 marathon.

The next year I did another 3-month period between the seasons - “building my aerobic base” and learning to use fat even more efficiently. After that I started running more sub-marathon distances, and set records throughout. I also ran my first 50 miler and a 3:55 marathon.

Last year (2017) I (you guessed it) did another 3-month period running below my MAF exclusively. My running team was amazed, as I moved from being a solid back-of-the-packer 23 minute 5k to running 20 minutes 5ks and other fast paces along the way to running my first 100 miler and a 3:31 marathon.

I mention all of this as a way to encourage you to take the plunge - my results are not abnormal - there’s REAL power in MAF.

Oh, and about hunger, just tell yourself that it’s not food your hungry for - it’s the hunger to be faster. Oh, and have some salt before you run - makes a big difference. :slight_smile:

Good luck, and reach out to me any time!


I ran 10 miles today at and below MAF in training for my 4th half marathon (1st in 6 years though). I’ve also been keto for the last month. Other than some mild foot/ankle soreness, I feel fantastic! This stuff really works!

(ianrobo) #36

and that is the key. about the lower stress on the body and of course recovery !

(Anti-Gravity Gains) #37

I did my first Mafetone run the other day. I started nasal (nose only) breathing per method discussed in the book The Oxygen Advantage. I highly recommend that book even though I’ve only read the first 80 pages :slight_smile:

I have decades experience running long distance including a couple 50Ks the last few years and 1 Leadville, CO marathon distance race (my favorite race yet).

I have been using Keto for 18 months.
I also lift weights a few times weekly.

I’m interested to see how adding this nose only breathing (did a 17 mile run the other day this way) + Mafetone along with my Keto way of eating pans out. So far, although new to the Mafetone and nasal breathing methods, it is going very very well.

(ianrobo) #38

so you was a normal carb burner doing these long runs, so for others reading this can you explain the difference in recovery and performance. Can you compare a race before and after Keto and how you felt ?

(Anti-Gravity Gains) #39

Prior to 18 months ago, as a carb burner, recovery post long run or race took at least 2 days. After using Keto (as well as I.F.), I find that by the morning after the race or a 4+ hour training run I feel great with very little soreness.
Perhaps best of all, as a keto adapted runner, I don’t worry about gut issues.

(ianrobo) #40

and that story is repeated many many times by lots of people so has to be more than anecdotal ?