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Track running and glycogen depletion, reduced performance.

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  • Track running and glycogen depletion, reduced performance.


    I've got a few specific questions if anyone out there can help me. I've done hours worth of reading but can't seem to find conclusive answers specific to my queries. I apologise in advance for the length of this post but I've got no one who would understand what I'm talking about without saying "no carbs are you mad?!" I've learned a lot from Jeff Volek and Stephen Phinney's studies on performance, plus Peter Attia's own personal experiments.

    I'm a competitive runner, I race 5K and 10K with the occasional half marathon and other distances, but my focus is the first two. As a consequence my training is very VO2max and Lactate Threshold based. I'm on the track twice a week where I do all my speed work which would consist of sessions ranging from say 15 x 300m to maybe 6 x 1 mile (plus a 3rd session of similar structure but off-road on grass/trails). All at the highest pace I can sustain to keep them all even, so whilst each individual effort isn't flat out, it's certainly in the VO2max region, so presumably very reliant on glycogen.

    Ok so my worries are due to performance and whether this diet is capping my ability levels and subsequent race performance. I've been on strict keto now for about 75 days and I'm fully fat adapted. Blood ketone readings on the monitor have been showing levels ranging from 1.1 to 3.1mM β-hydroxybutyrate so a definite state of nutritional ketosis with no risk of false readings from ketostix.

    What I've found is that for my aerobic paced running, long runs and suchlike I feel like I've got an endless supply of energy, I could carry on all day and I'm only limited by the soreness in my muscles from the previous day or morning's session. That is great. BUT I do feel like for speedwork my upper limit has been reduced. For example, last night we did 15 x 300m on the track and even though I completed the session fine, I felt that I didn't have an extra top gear to go into, especially during the last few efforts. I used to ramp up the pace and do an especially fast one at the end, but this time I was struggling to cling onto my club mates to do a 50s last rep, when 3 months ago I could absolutely drop them and throw in a 45s last rep. It seems raw power has been lost.

    So a few thoughts:
    (a) Every time I run now and feel anything bad like tiredness I instantly think oh it must be my diet and it throws doubt over the whole thing. In the past when I'd be tired I'd just get on with it but now I've got something to blame.
    (b) It's the back end of winter, maybe my speed is just low due to the time of year and I'll be strong come summer
    (c) Depiste keto being one of the only diets which supposedly maintains lean body mass, maybe I've lost muscle mass from my weight loss, not just fat. I stare at my quads now and think surely they were bigger than that before?! Lol.
    (d) I've read from some of the experts like Peter Attia and Jeff Volek that they don't recommend keto for say a 400m athlete as it would reduce their ability due to glycogen depletion, it is better for endurance athletes. Whilst I am actually an endurance event athlete, I use sprint and middle distance for training so I've got a cross over.

    So to continue this epic length post, a few questions if you can bear with me a little longer:

    (1) Ketosis apparently isn't synonymous with glycogen depletion according to a few experts, but how is that so when the whole way it works for weight loss initially is that you dump out your glycogen stores (plus water) and stay in a depleted state? When you become fat adapted do you just prefer to burn fat/ketones first and then only tap into your glycogen stores when you need to, so for intense exercise? Why would your body have loads of glycogen and not use it in front of fat/ketones?
    OR, do you just have very depleted stores but not ZERO stores and hence I can do most of my speed session but towards the end what little glycogen I had has been burned up hence nothing left for an all out final burst of speed?

    (2) I've been reading about CKD and TKD as a way of solving my problems. CKD doesn't make sense to me due to the fact I train every day, so the carb up at the weekend would make me think it wouldn't fit in with the other 5 days maybe. TKD however does sound very promising, from what I gather I basically stay in ketosis all the time apart from having carbs pre and post session which are essentially used for that session only and then I slip back I to ketosis as the carbs are all used up.
    How does that work though, surely that doesn't replenish glycogen stores having carbs before a workout, doesn't it take time to digest the dietary sources and then store them as glycogen? So wouldn't I essentially just still have depleted glycogen stores but a load of circulating fuel in the digestive system/blood stream? Is the circulating fuel able to be utilised efficiently enough to be the instant energy my muscles need or would they prefer to have glycogen already in them so to speak?

    Sorry for such a long post, I imagine it'll put a lot of people off reading it. I'm basically at a crossroads now whether to keep keto-ing on or to switch to a diet including carbs. The thing is I absolutely LOVE this way of eating, loads of fats and things that are great with no guilt!, so I'm reluctant to change, but first and foremost it's my athletic performance that matters to me. I would NEVER consider going back to the conventional high carb diet but if I had to change I would maybe look at some sort of primal diet including tubers etc as my carbs, or maybe some slow release complex carbs.

    Thanks for your time

  • #2
    Hmm so I guess this was maybe a bit too specific for people on here. Does anyone know any other forums where I might be able to get some help? I wish I could get one of the experts and sit them down and just bombard them with all my questions!


    • #3
      That was a very well-written post. I am not an expert, but I think you're pretty spot-on in your understanding of ketogenic diet and performance.

      You definitely lose your "top-gear" when you are glycogen depeleted. Peter Attia has blogged about this stuff called super starch that somehow restores muscles glycogen without impairing ketosis: super starch Archives The Eating Academy | Peter Attia, M.D. The Eating Academy | Peter Attia, M.D.
      Certainly not primal/paleo (derived from corn, I think), but it's something to consider at least.

      I'm not really sure if muscles can use glucose that has just been put into the bloodstream, or if you need to digest it and store it as glycogen first. I would think the rate that your muscles could use the glucose would be much higher if it was already stored as glycogen, but I could be wrong. I guess I need to do more reasearch on that to provide any useful information.


      • #4
        Thanks for the reply yodiewan. As it happens I've just ordered a load of generation UCAN superstarch today, it's not as readily available here in the UK but I can get it shipped from Spain.

        I'm interested to see whether if I have carbs pre-event do I then just run at my previous ability of my body? I suspect my top end will have adapted to being lower so the ceiling is lowered and would take some time to train higher again.

        I think my short term plan is to stay in ketosis for the foreseeable future and add in superstarch for hard training. I've got a 5K this Saturday which is going to be a sharpener for a big 10K the weekend after. I don't think I've got the courage to risk doing the 10K on no carbs, but I'll certainly give the 5K a go with some UCAN which is a great test.


        • #5
          Doing a cyclical ketonic diet is not a bad idea IMO, because you will be adapted to train periods on very low levels of glycogen, that's what I am doing myself in periods. Many people talks about getting "fat adapted", but what really happens is that you get more adapted to perform low on glycogen, and thats very relevant to competition! So personally I would do a cyclical ketonic diet, maybe loading up on healthy carbs 3 - 4 days a week depending on how much you are training, and deplete glycogen for the rest of the days...
          "All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident."

          - Schopenhauer


          • #6
            Thanks for your reply Cecile0.

            My superstarch is arriving this week so I'm hoping that might be a good way of fuelling up a bit. My plan for tonight though is to have SOME carbs before my track session, but only so much that will be used up in that session and then hopefully I'll return to ketosis shortly after. I'm having pure dextrose as my carb, certainly not primal or anything along those lines, but I might as well go straight to the source and not mess about with any frutose etc.


            • #7
              Just an update for anyone this may interest. I took some dextrose before my track session last night and felt terrific, the best I've felt in ages.

              I tested myself this morning and I'm back in ketosis so it's had exactly the effect I was looking for. Very pleased.