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Muscle glycogen storage for time trials

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  • Muscle glycogen storage for time trials

    I started about two weeks ago with Paleo not to lose weight, but to improve my cycling performance. My primary goal is to improve time trialing. These are (in my case) mostly between 8km and 30km. (Under 45 minutes).

    Furthermore in the winter I do some cyclocross. A typical contest is around an hour or so.

    I am typically interested in a more efficient use of energy within my muscles. Paleo seems a good way to achieve this.

    However, After one week the diet results were not too good. At 10km I lost about 30 seconds, and that's a lot! After some calorie counting I found that I was getting too little calories (about 500kcal short/day) Cause found... I guess this will improve if I'll eat somewhat more

    The FAQ at came up with this:

    The two primary sources of this fat are 1) fat stores directly within muscle called "intra-muscular triglycerides" (IMT), and 2) free fatty acids in your bloodstream whose source is from stored fat in adipose (fat) tissue. When the typical western, high carbohydrate diet (bread, rice, potatoes, refined sugars etc) is consumed the muscles adapt to this diet by storing more carbohydrate within muscle cells as glycogen, and simultaneously storing less IMT. Additionally, high carbohydrate diets tend to reduce the enzymes that allow fat stores to be broken down and utilized during exercise. As your body becomes more and more accustomed to a reduced carbohydrate intake, both IMT stores will increase along with increased efficiency of stored fat breakdown. Thirdly, liver, blood and muscle glucose stores will be more actively conserved. The net effect of all of these changes will be to keep your blood sugar levels within normal ranges during exercise. </blockquote>

    And that sounds a little scary to me... Muscle glycogen is an important factor for riding at maximum. If that will be less available it will probably have an effect on my performance. Maybe I will lose more performance by the glycogen than win by the increase of IMT.

    Anyone here on the forum can shine some light on this?

  • #2

    I don't know of anything in the technical aspects of energy pathways etc (only the basics).But what I have found is that my performance in any physical training has not declined since eating this way.

    So why not just take it on yourself to test how your body responds


    • #3

      I already started eating paleo.

      After as little as two weeks I can already feel some difference in endurance training, which is aerobic and not too heavy on the muscle glycogen storage. Haven't felt any big progress in more explosive activities like fitness training. But two weeks is too short to draw any conclusions on that already, I guess.

      My question is specific for that type of physical training where glycogen is an important factor and could possibly be a bottleneck. (eg. very intense just above aerobic threshold for >30 minutes).

      I am pretty sure paleo will work for explosive physical activity and also for long aerobic endurance activity, but my favorite activity is well time trialing and cyclocross...


      • #4

        I assumed that muscle glycogen would mostly be created by a more or less higher carbohydrates intake.


        Two Tunesian biologists found that a diet with more fat and less carbohydrates actually promotes the amount of glycogen in muscle tissue. Just as I hoped it would be. Let's see what happens in the weeks to come

        I read about this in Dutch, but the original can be found here: unfortunately I have no access to the full article...


        • #5

          On keep us posted on your results!!


          • #6

            I have no studies to cite, simply my recent experience. Over the last year I've participated in ultra distance events while eating a primal diet with low carb content. Results have been great, no fall-off from where I was when I was consuming a typical runner's diet. This past weekend was the real test however. I had a marathon, which has always been considered the ultimate test of glycogen storage and preservation. I maintained my low carb primal diet all the way through the event, including a race morning breakfast of 4 hard boiled eggs. Nothing else. The day was extremely hot so times were not optimal, but I figured my fitness was about 3:05 and I ran 3:12. Nobody else I know was that close to their goal times. The lack of carbohydrate loading to optimize glycogen stores didn't seem to hinder me at all.


            • #7

              What is the accepted wisdom for "in race" fueling in the primal method? I am going to be doing some multi-hour cycling (medium intensity) and am wondering what, if anything to eat during..


              • #8

                Get Primal, congratulations! That is so awesome!

                joeag, steak in your pocket... just munch when you need a boost.

                (kidding obviously. I have no clue)

                Eating lots but still hungry? Eat more fat. Mid-day sluggishness? Eat more fat. Feeling depressed or irritable? Eat more fat. People think you've developed an eating disorder? Eat more fat... in front of them.


                • #9

                  I'd theorize (note, have not tried in practice) that something with medium chain triglycerides, like coconut oil, would be best. They can be directly absorbed and used without need for the same bile salts, transporter proteins, etc. as longer chain saturated fatty acids. That would make them more immediately available to you in a race, and wouldn't produce any insulin that would shut down your access to in-body fat stores.


                  • #10

                    In a recent 24 hour race I had unlimited access to my food supply and used the Primal Pumpkin Loaf that I posted on here this morning. Nothing has ever sat so well in my stomach during a race. I suppose in a biking event you could carry it fairly easily, running is more difficult unless you have a special event like mine was.

                    I've often thought about the coconut oil as fuel. I've tried actual coconut flesh and it didn't sit well with me. I wonder about coconut butter, a happy medium?? Would it be possible to melt down coconut butter, form into blocks or balls, then cool so they could be carried? Not sure about the consistency and whether they would stay together, I usually just melt mine over eggs.


                    • #11

                      Yeah, coconut oil is going to be a little squishy out in the sun. I'd try to do something like how truffles are made: treat the coconut oil as a soft ganache interior, roll it into little balls, and freeze them. Then coat the balls in something else..would be crushed nuts, or could be a dark chocolate shell (really super dark chocolate will hold up better in the heat).

                      A shell made of melted sugar would make them even more weather resistant, but I guess we don't want to do that. I'll try see if I can think of anything else that is primal and can form a hard shell and doesn't melt until 120 F or so.


                      • #12

                        Yesterdays training (paleo day #15) was a complete disaster. No energy - legs felt ok, but heart rate would not go up.

                        Energy levels have only gone down since starting eating Paleo. Hope this will change soon.

                        Will take some rest today and see what happens tomorrow...

                        @Nick. Try some little dried fruit like apricots or figs on longer training sessions.


                        • #13

                          Make the powerballs and freeze em.Should last a while longer that way!


                          • #14


                            I changed to Paleo style life almost a year ago. I was then in the best shape of my life, and had different ways of measure my progress and status. I lost at least 35 W of my FTP and the overall performance in all activities were poor. I also had an increased heart rate in rest and moderate actvity. During harder exercise it was mad! Had bpm figures I've never seen.

                            It took at least 3-4 months before things started to normalize, but the power loss didn't rebound. Now I better than last year in all aspects, but say it took me 6-8 months before I was back in a state where I never gave carbs a thought.

                            I read paleo for athlets, tried forums on the web etc. The thing was that I couldn't just do minor compensation with carbs and get to previous power levels. When I changed my overall lifestyle and limited my carb intake, my body needed time. More than anyone else I've read about on the web.

                            Today I will do TTs of 20 km without any change in food intake before, during or after.

                            On rides more than 100 km I need additional carbs and then I mainly use sports drinks as source.

                            When I do intervall in blocks, say 3 days in a row, I increase my carb intake overall, fruit, potatos, berries etc. If I fear that I will deplete my glycogen storage I can also take some sports drink with protein directly after exercise or race.

                            So I would recommend you to back off a bit an consider what you would like to achieve. Improve in a month, spend the time on intervalls. Get a life that you enjoy, and a good base for training, i.e. going primal. Give it some time, and take a couple of weeks of the bike in order to get over the worst adoption phase.

                            Good luck!


                            • #15

                              Mr Scott,

                              Thanks for your reply!

                              So, you're saying when I'll be patient, it will make me faster in the end. (Based on your experience).

                              My goal is not to be superfast next month. Next season will be more important.

                              Are you (pretty) sure the gain after a year is on the account of your paleo diet? Or have you been training better?

                              Between last year and this year I made a huge improvement (almost a minute at 10km TT) by changing my diet. (No changes in training). I went from a standard Dutch diet to a diet that incorporated much more fruits and vegetables. But still lots of carbs (pasta).

                              Now, I try to improve more by going paleo. However, I will still be drinking some Kefir dairy.

                              And still my overall health is more important than winning a race... So I think I will stick to this for some time longer...