The Carbohydrate Loading Conundrum

90 Comments

Written by: Kevin Cann

Carbohydrate loading is a dietary means that has been used to improve performance in endurance athletes.  The theory behind carbohydrate loading is to maximize the stored amount of carbohydrates in our body, as glycogen, to yield more energy.  This is done in two steps.  The first step is to adjust carbohydrate intake for a week to between 50-55% of total daily calories.  Fat and protein are increased to make up for any differences in caloric intake.  Training remains the same.  This allows the athlete to dump the stored glycogen he or she already has and make room for the second step.  The second step takes place about 3-4 days from the event.  This step calls for increasing carbohydrate intake to about 70% of daily calories.  Foods that contain higher amounts of fat are decreased and training is decreased as well (Mayo Clinic staff, 2011).  Is this truly the safest and most effective way for endurance athletes to fuel their bodies leading up to a race?

In a study done by Rauch in 1995, he tested the pre-exercise muscle glycogen content as well as performance in endurance trained cyclists after a three day carbohydrate loading protocol.  The study concluded that the carbohydrate loading group increased pre-exercise muscle glycogen content as well as power output and total distance covered in one hour (Rauch, 1995).  This study proves that carbohydrate loading has positive effects on performance.  More importantly it shows that having maximized glycogen stores can increase performance.

In another study done by Lambert in 2001 they tested a high fat diet and a habitual diet before a carbohydrate loading protocol.  This study showed that the high fat diet group increased performance greater than the group on the habitual diet before a carbohydrate loading phase.  The study also concluded that the high fat group increased performance while having a higher reliance on fats as energy (Lambert, 2001).  Any exercise lasting longer than 240 seconds requires glycogen as well as fatty acids for energy (NASM, 2010).  These studies combined state that maximizing glycogen stores while increasing our reliance on fatty acids can increase overall performance in endurance athletes.  Increasing carbohydrates in the diet can come with a lot of negative consequences as well.

When endurance athletes add carbohydrates to their diets they typically will add grains in the form of breads and pastas.  This can be hazardous to the health of the athlete for a number of reasons.  Some grains such as; wheat, rye, and barley, (and usually oats due to cross contamination) contain a commonly problematic protein composite called gluten. Gluten is partially made up of storage proteins called prolamins. While some other grains technically don’t contain gluten, they have their own simlar prolamins as well, which can be problematic for many people. Most prolamins are formed from repetitive amino acid sequences that contain high amounts of glutamine and proline.  Examples of prolamins are gliadin found in wheat and avenin found in oats.  Gluten and these prolamins can cross the intestinal barrier and also cause an inflammation response.  The tests for gluten sensitivity actually look at antigliadin antibodies in the blood.  The prolamins and gluten entering the blood stream can also lead to auto-immune disease in susceptible people.  The protein zonulin is in control of regulating our intestinal permeability.  Eating foods high in prolamins and gluten will increase the amount of zonulin in our intestines.  This creates extra spaces for undigested proteins to pass through.  Our bodies will treat these undigested proteins as dangerous and launch an immune response.  The antibodies that are created can then attack other systems in our bodies.  This can lead to disease as well as inflammation in areas such as the athlete’s joints.  Training for endurance sports already causes inflammation and the diet needs to counteract that.

Another problem with eating grains is the increased amounts of phytic acid.  Phytates are substances that bond to the metals; iron, zinc, calcium, and magnesium in our bodies.  This does not allow for the minerals to be absorbed and used properly.  One study conducted by Davidsson in 1994 showed that decreased amounts of phytic acid in baby formula increased the bioavailability of iron and zinc (Davidsson, 1994).  Iron is especially important in endurance athletes because it supplies the protein hemoglobin in red blood cells which are responsible for carrying oxygen to the working tissues.  According to the USDA, endurance athletes are more prone to iron deficiency.  Diet should not further that deficiency, but supply the body with correct nutrients to avoid a deficiency.

Zinc is responsible for cellular respiration, DNA reproduction, maintaining cell membranes, and clearing out free radicals.  Micheletti stated in the Sports Medicine Journal that increased amounts of carbohydrates as well as decreased amounts of fats and proteins lead to deficiencies in the mineral.  The deficiencies in athletes can lead to decreased bodyweight, fatigue, and increase the risk of osteoporosis (Micheletti, 2001).

Calcium, magnesium, phosphorous, and iron are also important in bone formation.  Athletes are at an increased risk for stress fractures (Clarkson, 1995).  This is especially true for endurance athletes that log a lot of miles per week in training.  Maximizing absorption of all these minerals is important to keeping the athlete healthy.

These are not the only issues associated with carbohydrate loading.  Every person is different.  A common side effect for ingesting an increased amount of carbohydrates is gastrointestinal distress.  This can severely hinder performance in athletes.  According to the NIDDK the body does not breakdown some carbohydrates because of the lack of certain enzymes.  As this undigested food passes through the intestines gasses such as hydrogen, carbon dioxide, and methane are produced.  This can cause gas and bloating in the athlete, which also can affect performance (NIDDK, 2011).

There is a better and healthier way to go about maximizing glycogen stores, increasing the body’s reliance on fat as energy, and increasing absorption of key minerals while also decreasing bouts of bloating, gas, and gastrointestinal discomfort.  To maximize glycogen stores, glycemic loading is effective.  Ingesting high glycemic carbohydrates 30 minutes post exercise can help the athlete replenish lost glycogen.  Cordain recommends taking in .75g of carbohydrates per pound of bodyweight.  Instead of consuming breads and pastas that are high in antinutrients and undigestable proteins the athlete should consume high glycemic fruits or sweet potatoes.  For endurance athletes that took part in more demanding exercise this should be repeated about 90 minutes to two hours following the workout due to the continued burning of muscle glycogen during recovery.  The athlete also needs to rehydrate and consume protein in a 4:1 carbohydrate to protein ratio (Cordain, 2002).

To increase nutrient and mineral absorption the rest of the day the athlete should stick to lean meats, fish, eggs, fruits, and vegetables.  Preferably the meats will be grass fed to contain higher amounts of omega 3 fatty acids.  This coupled with eating wild caught seafood can increase the athlete’s amounts of ingested omega 3 fatty acids and help fight inflammation.  Also, adding healthy fats to the diet can increase performance by increasing the body’s ability to rely on those fats for energy.  Grass-fed meats as well as wild caught fish are also great for this.  To increase fats more in the diet olive oil can be used in salad dressings or sprinkled on vegetables.  Foods can also be cooked in coconut oil to reap the health benefits of the medium chain fatty acids.  Fruits and vegetables are second to no foods in vitamins and minerals and are also important to keeping the athlete healthy as well as aiding in recovery.

Endurance sports increase the amount of oxygen that is utilized by the body.  This also increases the amount of free radicals in the system.  These free radicals can cause harm to tissues and hamper cellular repair (Witt, 1992).  This makes it even more important for the endurance athlete to be getting proper nutrition.  High carbohydrate diets that lean on grains for calories can decrease the absorption of these important nutrients and lead to the athlete breaking down.

In conclusion, an endurance athlete needs to be aware of the negative implications food choices can have on performance.  A carbohydrate loading protocol that leans on grains for calories can hinder recovery and performance.  Studies have shown that maximizing glycogen stores while increasing the body’s reliance on fat for energy can increase performance.  This can be accomplished by eating high glycemic foods post workout and eating a diet that is rich in lean meats, fish, eggs, fruits, and vegetables.

 

 

 

References

Witt, EH (1992).  Exercise, oxidative damage and effects of antioxidant manipulation.  www.pubmed.gov.  Retrieved on January 14, 2012.

NIDDK (2011).  Gas in the Digestive System.  www.digestive.niddk.nih.gov.  Retrieved on January 14, 2012.

Clarkson, Priscilla (1995).  Exercise and mineral status of athletes.  Journal of the American College of Sports Medicine.  Retrieved on January 14, 2012.

Davidsson, L (1994).  Iron bioavailability studied in infants: the influence of phytic acid and ascorbic acid in infant formulas based on soy isolate.  www.ukpmc.ac.uk.  Retrieved on January 14, 2012.

Lambert, EV (2001).  High-fat diet versus habitual diet prior to carbohydrate loading: effects of exercise metabolism and cycling performance.  www.ukpmc.ac.uk.  Retrieved on January 14, 2012.

Mayo Clinic Staff (2011).  Carbohydrate Loading Dietwww.mayoclinic.com.  Retrieved on January 14, 2012.

Rauch, LH (1995).  The effects of carbohydrate loading on muscle glycogen content and cycling performance.  Retrieved on January 14, 2012.

Micheletti, A (2001).  Zinc status in athletes: relation to diet and exercise.  Sports Medicine Journal. Volume 31 Number 8.  Retrieved on January 14, 2012.

Cordain, Loren (2005).  The Paleo Diet for Athletes.  Rodale Publishing.  Retrieved on January 14, 2012.

NASM (2010).  NASM Essentials of Sports Performance Training.  Lippincott, Williams, and Wilkins.  Baltimore, MD.

 

Kevin is owner of Genetic Potential Nutrition.  He is a holistic nutritionist, wellness coach, and strength coach.  He works with people fighting illness, to competitive athletes.  Check out his site at www.geneticpotentialnutrition.com.

Leave A Comment

Comments

Comment using Facebook

Comment using RobbWolf.com

  1. James
    February 8, 2012 at 2:48 am

    As someone who has effortlessly lost weight the last few months using a low carb paleo diet, but now looking to re-introduce some carbs to raise the intensity of my workouts that was a great read, thank you.

    I have a few related questions, if anyone could answer it would be hugely appreciated:

    1. Is the main goal of restoring glycogen levels post-workout to aid with body recovery and tissue repair?
    2. I mean to say if the next workout was done 24-28hrs after a post-workout carb meal, wouldn’t your glycogen stores be depleted by then anyway on a low carb diet?
    3. And so would it be additionally beneficial on such a diet to eat non-problematic high GI carbs pre-workout, to maximise performance?

    • Amy Kubal
      February 8, 2012 at 6:19 am

      James!

      Yep! We want to replenish and recover your muscles and glycogen stores and give you energy!!
      If you play it right your stores will be maintained between workouts – restock post and keep it steady with plenty of non-starchy vegetables and adequate diet in the interim. And a quick dose of pre-workout carbs can work to bolster performance – I use this technique with many of my athletes!
      http://www.robbwolf.com/consulting/amy-kubal-consulting/

      • Rachael
        February 8, 2012 at 12:13 pm

        And it works too!

      • Martin
        February 8, 2012 at 2:42 pm

        Amy, would you recommend the carbs pre/post for any marathon-oriented workout? How about low intensity long runs, way below the anaerobic threshold?

        • Amy Kubal
          February 8, 2012 at 6:18 pm

          Definitely experiment in training prior to race day!! NEVER do anything ‘different’ on the day of the event! Try incorporating some carb for your longer workouts (race simulating) and see how things go – tinker with it until it’s all dialed in!

  2. Monte
    February 8, 2012 at 4:22 am

    Thanks Kevin! I’m training for a Marathon and moving towards paleo. This helps with figuring out what to eat per and post workout. Anyone have ideas on high glycemic fruit besides bananas?

    • Amy Kubal
      February 8, 2012 at 6:16 am

      Pineapple, dates, dried fruits, baby food – these are all higher on the GI side. Post workout focus on yams, sweet potatoes, pumpkin, winter squash, roots and tubers to get the most bang for your buck (these work great pre-workout too!!) http://www.robbwolf.com/consulting/amy-kubal-consulting/

    • Martin
      February 8, 2012 at 2:40 pm

      How fast do you want to run the marathon?

      • Monte
        February 21, 2012 at 6:52 am

        Martin – I’m a mid packer, so just hoping for sub 4.

  3. Jay Ogg
    February 8, 2012 at 7:00 am

    Kevin,

    What do you recommend in terms of immediately pre- and during- event feeding? For example: I’m participating in my second Tough Mudder event this spring. Last year, I was starving about halfway through and began experiencing extreme muscle cramping by the time I was 3/4 through. I’d like to avoid this if at all possible this time around, and if possible, re-feed during the event.

    Pre-event (probably around 2 hours prior to ensure digestion), some good healthy bacon and eggs in a sweet potato hash. Then maybe throw down a banana or raisins at a water checkpoint. What are your thoughts on this?

    Otherwise, great article. I appreciate the citations as well!

  4. Pierre
    February 8, 2012 at 7:14 am

    Great article thanks Robb!

    This article is also interesting in that Peter tested his VO2 max over a 12 week period both out of ketosis and in ketosis.

    http://waroninsulin.com/how-a-low-carb-diet-affected-my-athletic-performance

    • Robb Wolf
      February 8, 2012 at 10:13 am

      Pierre-
      It’s good stuff but not anything new:
      http://www.nutritionandmetabolism.com/content/1/1/2

      And once we dip into anaerobic power output the wheels fall off the wagon in ketosis.

      • Pierre
        February 8, 2012 at 10:56 am

        Yes Stephen D Phinney has been doing some great stuff for a long time. It is good to see so many people pushing our understanding of the human condition outside the boundaries set by the mostly useless recommendations of the US Government.

      • Pierre
        February 8, 2012 at 2:30 pm

        Robb the wheels coming off the wagon might be simply slower adaptation to being in Ketosis…at least according to commentators on Peter’s blog.

      • Martin
        February 8, 2012 at 2:48 pm

        But maybe, if in a ketogenic state the anaerobic threshold seems to be raised, you don’t have to get anaerobic (if your goal is endurance performance)?

  5. kevin cann
    February 8, 2012 at 7:41 am

    Hey man,

    Pre-workout stuff isn’t so black and white from what I have seen. There is some good data out there suggesting not to eat within 2 hours of an event due to blood flow leaving the gut to go to working muscles. If you do eat within this window be sure to consume 6-8oz of water for every 100cals consumed because that is roughly what is needed for digestion. I have messed around with caffeine pre-workout with pretty good success. This all requires some individual experimentation to see what works best around race time, try some stuff out!

  6. Kyle Kranz
    February 8, 2012 at 8:25 am

    I consume a low fat raw vegan diet and agree with everything you said about grains. However another method of maximizing glycogen stores and improving lipid oxidation is to simply perform fasted morning workouts. http://www.runningonthewhiteline.com/2012/01/endurance-training-while-in-fasted.html

  7. Olga
    February 8, 2012 at 9:36 am

    What about doing a non-grain carb load one meal per day (dinner) twice per week, as suggested by Rob Faigin? Would this not diminish the deleterious effects of insulin (only two spikes per week rather than multiple), while effectively loading your glycogen stores?

    • Robb Wolf
      February 8, 2012 at 10:03 am

      I think this is a pretty solid way to go, or even just post WO. This based on body-fat levels, work output etc.

    • kevin cann
      February 8, 2012 at 10:35 am

      I agree with Robb using this post wo. Seems people respond better with the higher insulin sensitivity in the muscles post workout. Try them both out and see which one works best!

    • Olga
      February 8, 2012 at 11:34 am

      It’s been a while since I read Rob Fagin’s book, but I think he argued against carb loading after a workout becuase it would blunt the growth hormone incease post workout. He also advises against carbs within 90 min. of going to bed for the same reason. If this is correct, to me it still makes more sense to load up glycogen stores first. If you’ve been on a paleo/low carb diet for a while, I don’t think isolated insulin spikes are a problem, and may even be anabolic.

      • kevin cann
        February 9, 2012 at 8:43 am

        Hey Olga,

        Great stuff! In my experiences if the glycogen stores are not addressed post workout then we get an increase in cortisol which will also blunt any protein synthesis hormones. Try some stuff out and let us know!

  8. Olga
    February 8, 2012 at 9:38 am

    ps. carb sources such as yams, potatoes, rice, taro, etc.

  9. Wout
    February 8, 2012 at 9:43 am

    I keep reading the “lean meats” thing. Why not fatty cuts if one is trying to eat a high fat diet?

    • Robb Wolf
      February 8, 2012 at 10:03 am

      It’s smoke and mirrors amigo. We say that to keep the fat phobic happy, then do the exact opposite.

      • Wout
        February 9, 2012 at 9:27 am

        “For lunch I had lean meat, veggies, and my starch source was in the same room as healthy whole grains! I had the ‘Sauce Graisse’ which probably means it was made from grass!”

        Hmm, I could do that :-)

      • Luke
        February 9, 2012 at 10:11 am

        Are you sure that’s a good approach? Because it’s damn confusing for beginners.

    • Peggy Holloway
      February 8, 2012 at 2:57 pm

      Glad you asked this question. I was wondering the same thing.

  10. Mitch
    February 8, 2012 at 9:51 am

    Interesting post. In “The Lore of Running” Noakes goes into great detail about carb-loading versus “high fat loading”, and I definitely recommend reading it, if you haven’t. He freely admits that there’s a distinct lack of research into “well adapted” high fat diets, but notes that a few elite triathletes perform very well on relatively low carb diets. He also makes a great point about animals (horses and dogs) that do extremely poorly on a low fat diet (although… what the hell does a horse eat when he’s on a high fat diet??)

    The fact that high carb intake means high carb burning is one of the interesting factors; if the goal of a long distance endurance athlete is high fat burning, carb loading seems to be contrary to that goal.

    • kevin cann
      February 8, 2012 at 10:39 am

      The theory with high-carb diets is replacing lost glycogen. Even though fats are the primary energy source during a marathon, glycogen stores are still being depleted and glucose is still necessary for red bood cells transporting oxygen to working tissue. However, there comes a point where too much carbohydrates, especially the wrong ones, can have a negative impact on performance and health. The theory behind high fat diets is that the body will be better adapted to using these fats as energy. The anecdotal data is enough for me. I have way more energy fighting on a paleo diet then if I stuff my face with high amounts of grains and my clients have responded very similar to myself.

  11. No Dice
    February 8, 2012 at 10:47 am

    I understand marathons and cycling fall into this but how does this information translate to something along the lines of Hockey or Soccer, or even American Football, something where it’s explosive and sustained but generally in 1-3 minute bursts, but repeatedly over the course of a 30-120 time span. I have just recently started being interested in athletics (beyond spectating) so understanding which sports require what forms of fueling is still a bit blurry to me.

  12. Dr. Mike Tremba
    February 8, 2012 at 1:12 pm

    You brought to light something that I wasn’t aware of:

    The damage of Phytic acid in our bodies from Carb. loading.

    I know that soy has a great deal of phytates, but didn’t realize that the grains you mentioned did as well (although it makes a lot of sense).
    Anyway, I know it’s a slight twist from the topic, but when you combine the amounts of soy AND grains consumed in the modern diet, it’s no wonder we have so many nutritional problems related to the malabsorbtion of minerals.
    Thanks for the great post.

  13. Peggy Holloway
    February 8, 2012 at 3:06 pm

    I am by no means an “elite athlete,” but my partner and I do long-distance, multi-day bike trips, often cycling 50 to 70 miles a day at an average of 16 to 18 mph. I have been a low-carber for years, but my partner has always eaten pretty much whatever he wants. Last summer, he quit after 5 days of a bike trip, feeling tired, and acknowledging that his 40 excess pounds were “weighing” him down. It had been his experience for years that he could gain some winter weight, then lose it once he started training. The past few years, that wasn’t happening anymore. He decided to try cutting carbs and two weeks later I joined him for a 4-day trip. He was amazed that he could bike 40 miles without any breakfast, stop for steak and eggs, ride another 30 to 40, never snack at the SAG stops, and have more energy than he ever has. We watched everyone else snarfing down cookies and Gatorade at the SAG stops, while we drank water. The others breakfasted on pancakes and carbo loaded each evening at pasta bars. We ate 3 good, but not enormous high fat, low-carb meals a day (often having to find local restaurants as the ride hosts seemed to think all bikers eat is pancakes and pasta) , but never felt the need for snacks and never “hit the wall” By the end of the summer, Ken had lost 40 pounds.
    Ken will be 70 next month and I will be 59. We have 2 rides planned for next June and are considering a cycling tour in France for July.

  14. Rob
    February 8, 2012 at 4:01 pm

    I just finished reading a fascinating book called The Science of Soccer, which makes a compelling argument in favor of a high carbohydrate consumption for soccer athletes. It states that athletes need a minimum of 7 grams/per kg of carbohydrate to replenish glycogen, and that any less could diminish performance by a lot. In the book, it states that a single 15 meter sprint in soccer has the potential of diminishing glycogen by almost 33%, and as you very well know, soccer players do multiple sets of these sprints throughout the game. I have personally experienced both a high fat(60%) and a low carbohydrate (10%) one, and currently a higher carb (55%) lower fat one (20%). My endurance was way better on the high fat diet, but my sprinting ability and speed were terrible. Currently, on my high carb diet, I am able to sprint hard and jump but I lack energy and endurance. Maybe my high carbohydrate intake is affecting my blood sugars and decreasing my performance? Do you think upping my fat and skewing my macronutrients ratio to an even split of fat and carbs (40%-40%) will improve my overall performance.

    I am currently consuming about 500 grams of carbs but I am thinking if lowering that to about 400.

    • kevin cann
      February 9, 2012 at 8:49 am

      Hey Rob,

      Tinker with the carb totals and see where you feel comfortable. I would add in sweet potatoes and yams to increase totals and some fruits. My M.S. is in human movement with an emphasis in sports conditioning and a lot of it could be how you are training. At my gym we do a lot of agility drills and short intense sprints and I am PRing those on about 100g of carbs per day. I also fight mma and I have more energy then most of my teammates at that as well. Feel free to email me any questions too man, kevin@geneticpotentialnutrition.com

    • Pierre
      February 9, 2012 at 11:25 am

      You have to be careful about doing short term studies of the effects of ketosis on your athletic performance as it takes quite a while to acclimate your body to the change from high carb to very low carb. Weeks instead of days…

        • Rob
          February 10, 2012 at 3:59 pm

          Do you guys have a rebuttal to Anthony Colpo’s analysis of Phinney’s work?

          http://anthonycolpo.com/?p=1535

          • Robb Wolf
            February 11, 2012 at 10:13 am

            Rob- I’m not sure what you mean. How to I rebute a fact: Low carb can and likely will tank elite level athletic endeavors, especially if they are glycolytic in nature. Can you flesh this out for me, I’m confused what you are looking for.

          • Rob
            February 11, 2012 at 12:01 pm

            My bad Robb W., I thought you were implying that a high fat diet was better than a higher carb one for elite athletes. My mistake :). I must say though, that my N=1 experience with a 40/40 split has improved my performances much more than a super high fat or a super high carb diet have.

          • kevin cann
            February 12, 2012 at 6:38 am

            Hey Rob,

            Are you looking for something soccer related? Here is some breakdown on the sport taking from a post on strengthcoach.com.

            Elite-level soccer players will cover 9-13 km over the course of a match (1-3). This is the most general and least important statistic. It’s not the fact that soccer players cover this distance; it’s how and when they do so (we’ll get to that soon).

            • The average aerobic load during a soccer match is 70-75% of maximal oxygen uptake (1,3).

            • The average heart rate achieved during a soccer match is 85% of maximum. The heart rate range is 65-98% (1).

            Now, let’s look more closely at the contributions from different speeds of movement:

            • High level soccer athletes spend approximately 60% of their time on the field either standing or walking (2).

            • If you add jogging (18-20%) to the previous statistic, approximately 72 minutes of a high-level soccer match is spent at recovery-level intensity (2).

            • Hard runs and maximal-effort sprints contribute approximately 2-4% of match play with maximal effort sprinting contributing 1-1.5% or 54-80 seconds (2).

            • The average number of high intensity runs (hard runs and sprints) is 50-150 (2) and the average time in between is 40-56 seconds (4).

            • The average number of sprints is 20-60 per soccer match (2, 4). If you were to divide the total match time by these figures, the average time in between each sprint would be 1:30-4:30. Short sprints (read below) followed by this amount of rest are not likely to induce significant fatigue (4). In this case, bouts of repetitive sprints are more likely to produce fatigue within a soccer match.

            • The average distance per sprint is 10-20 meters and average duration is between 2-3 seconds (4). Although soccer-specific data is lacking, the maximum sprint-duration during an elite field hockey game is approximately 4 seconds. Field hockey and soccer data have proven to be similar, so some overlap of analysis may be appropriate (5). •

            Mohr, Krustrup, and Bangsbo (2003) demonstrated that total distance covered, distance covered by high intensity running (28% greater) and distance covered by sprinting (58% greater) were greater by elite-level soccer players than by sub-elite players (2).

            Even though the majority of time during a soccer match is spent standing, walking, jogging, and low-speed running (which contributes an additional 10% (2)), this type of movement does not contribute to success. High-intensity running and the ability to recover from such bouts contribute significantly to performance in soccer. This is demonstrated by the fact that elite-level players sprint more and cover more distance over the same match length than sub-elite players (2).

            After the sprint is concluded our body should be relying on fats as energy. Check out Excess Post Oxygen Consumption (EPOC). A moderate carb diet (added sweet potatoes, yams, fruits tinkered per individual comfort and performance) and proper training has been successful with the soccer athletes I have trained. It is more about recovery then the actual sprints. Hope this helps.

          • Rob
            February 12, 2012 at 4:42 pm

            Very thought provoking information Kevin!! Thanks.

  15. Mike T
    February 8, 2012 at 5:03 pm

    Have you read Peter Attia’s blog. He has been in ketosis for year or so and is able to perform extreme anaerobic workouts. He does caution that he has spent the time to completely adapt to a high fat diet.

    • Peggy Holloway
      February 8, 2012 at 7:22 pm

      Steve Phinney has done excellent research into ketogenic diets and athletes and it does take about 2 weeks to ketone adapt, and carb intake must remain low to stay in ketosis. It has worked for me for 12 years.

    • Simon
      February 10, 2012 at 2:42 pm

      Peter Attia says of the results of his performance testing: “The one drawback, it seems, to completely eliminating carbohydrates from my diet was a loss of all-out top end power. For someone like me, this doesn’t seem to hinder performance too much, but I was trying to win an Olympic gold medal in the 400 meter run or the 100 meter freestyle, it seems I’d be better off with some carbohydrate in my diet.”

      The problem physiologically is that for “extreme anaerobic” performance, the body cannot oxidise fat fast enough. Looks like this might apply to ketones as well. For context, my obsession is running a fast mile/800m, which at my age means well sub-5 minutes. So I *THINK* I need carb-fuelling: the training for this requires not ultra-short anaerobic/alactic sprints, but sustained pain :)

      • Robb Wolf
        February 11, 2012 at 10:14 am

        You absolutely do.

        • Simon
          February 11, 2012 at 5:16 pm

          Thanks Robb, I really appreciate the confirmation.

          To add to that, what was interesting about the Phinney/Colpo material (above) was that Phinney was talking about aerobic capacity and power and, I think, confusing the two; and that even although Phinney’s review supports the idea that low/virtually no carb is feasible for ultra-endurance activity – ie hours and hours @ moderate effort – Colpo is blowing that out as well.
          From Colpo’s article it was a revelation to me that a guy who is always being promoted as one of the ultimate “low carb” icons, “ultraman” winner Jonas Colting, has had to personally correct the impression low-carb gurus are fostering about him. In his own words: “I´m not a die-hard low-carb person in every stretch but rather believe in the “train low-race high” concept which includes more carbs during ardous endurance events.”

          Thanks for giving us access to the Phinney article.

          • Robb Wolf
            February 12, 2012 at 10:21 pm

            If you listen to the podccast I;ve recommendaed the block periodized trainign with bouts of low-carb, followed by carb loaded competition. Not much new under thee sun.

  16. Alex
    February 9, 2012 at 6:53 am

    Similar topics are being discussed over at the MDA boards and you’d be amazed at the people who viciously defend low carb and treat all sources of carbs as evil. The general stance that myself and others over there take is basically that while low carb certainly has it’s time and place,especially for people with damaged metabolisms and so on,it is by no means optimal in a long term sense or for someone with high activity levels. I tried going low carb and working out….I was miserable. The weights have never felt heavier,I was chilled and aching,and my overall performance suffered terribly. I introduced carbs from healthy sources back into my diet and all that went away fairly quickly,and my fat loss hasn’t been negatively impacted. I did gain back some weight,but,and correct me if I’m wrong,this weight isn’t fat but water and glycogen as my glycogen reserves replenish themselves. I’ve gained weight according to the scale, but I’ve seen no noticeable change in my body fat percentage since adding the carbs back in.

    • Dana
      February 14, 2012 at 12:18 am

      I am one of those people who thinks all carbs are bad. LOL I have been carb free for 4 years. I eat a high fat diet of animal products only. I have been an athlete/runner most of my life and always had a problem with endurance. Since eliminating carbs I have more endurance, strength and energy than ever before and it is not by a little, it is MUCH more. It did take about 2 years to get to that point though. Most people can’t go carb free 2 months let alone 2 years so most people won’t get to experience the carb free “nirvana”.

      I just popped in here to say that a carb free diet can indeed improve your strength and performance, but only if your body has fully adapted to using fat for energy. This takes longer than you think. (almost 2 years for me) Technically you can be “keto adapted’ in 2 weeks or so, but that doesn’t mean your whole body knows how to function like this yet. Once your body completely adapts to using fat for fuel it is amazing what you can do. It totally changed my life. It’s just one of those things you have to do on your own to believe it. But, how many people are willing to sacrifice their precious carbs for 2 years to see if it works for them?

      • Simon
        February 14, 2012 at 12:27 pm

        I’m very interested in what you call a carb free diet. Are you doing a full-on Inuit diet (85% fat, 15% protein or so)? You’re saying high-fat animal products only, so NO vegetables, fruit or nuts at all? What about milk and cheese?

        On that diet I’m sure your endurance is OK; what type of athlete/runner are you? How do your times compare pre- and post-“Inuit”?

        Sorry about all the questions :)

        • Dana
          February 20, 2012 at 8:34 am

          Yes, full on Inuit. No vegies, fruits or nuts. I feel best on all meat, kudos to those who can eat vegies, fruit and nuts, but I feel like crap for a few days after eating that stuff, so it’s just not worth it. (nothing tastes as good as being healthy feels!) Dairy is my downfall. I shouldn’t eat it and have stopped eating it as of a few weeks ago. Dairy makes me tired and my skin breaks out. I am not sure if it the salt or the dairy, but something isn’t right about it.

          I haven’t timed my runs. I just run my usual loop. I was always a short distance sprinter. 220 max. I never had the endurance to run fast any further. Now that I’m older I just run in the park, but I run for 10mins/walk for 5 mins, etc. I could never run the whole 5K loop. Then one day I ran half the 5K without stopping. I thought it was a fluke. Ever since then I can run and run and don’t have to stop, I can run the whole 5k loop without stopping. It’s weird.

      • Peggy Holloway
        February 17, 2012 at 2:49 pm

        Dana, I’m on your side. But you are probably like me, extremely insulin-resistant and have bad reactions to even small amounts of carbohydrate. I am having a “yucky” afternoon after lunch at a local restaurant that seemed like a safe bet, but I have to wonder what they put in their omelet. One would think an omelet with cheddar artichokes, and avocado would be great for me, but I had a touch of hyperactivity followed by an almost comatose state for the last hour or two and I’m already hungry 3 hours after finishing lunch. That’s not normal, so I have to guess they put something carby in the omelet (pancake batter like IHOP?) – maybe they used skim milk? It doesn’t take much to make me miserable, so yeah, I guess I consider all carbs to be pretty much evil.

        • Dana
          February 20, 2012 at 8:40 am

          Peggy, the artichokes and avocado would have made me miserable. (gas, bloating & tired) I can’t handle any carb, whether it comes from an avocado or a piece of bread. There are no good carbs in my world, a carb is a carb. :)

  17. Derek
    February 21, 2012 at 6:24 am

    Then there’s the underground funk of gluten exorphins raising prolactin in mice/rats/human, which one would think would affect testosterone, and ultimately performance. Gluten exorphins, wheat version of phytoestrogen.

  18. Martin Ankerl
    March 12, 2012 at 3:15 pm

    I’ve just read “The Truth About Post-Workout Nutrition” [1] where they state that it’s actually best to wait 30-60 minutes after the workout, in this time glyconeogensis works hard to restore the glycogen in the muscles. After that you should get 40-60 gram of protein. They write that its more important to be insulin sensitive than to have an insulin spike.

    [1] http://chadwaterbury.com/the-truth-about-post-workout-nutrition/

    • Ed
      April 10, 2012 at 6:34 am

      so now I’M REALLY CONFUSED. RW- Does the Chad Waterbury article actually pan out or is it true pseudo science?

  19. Courtney
    April 17, 2012 at 6:24 pm

    Quick question: My crossfit group meets 3 times a week at 9PM, & we do the full WOD’s on crossfit.com (intense stuff). By the time we are finished & I get home, I’m usually ready to crash, so I don’t eat much, or anything most times. It not only worries me to eat right before bed, but it also worries me that I’m not eating anything. Thoughts?

    • Robb Wolf
      April 17, 2012 at 7:43 pm

      Yea, that’s tough. Just try to re-feed based on activity level. If you start getitng chubby, dial backa little. Not an optimum situation, just need to tinker~!~

      • Courtney
        April 17, 2012 at 8:18 pm

        Okay I’ll have to experiment. Any ideas on foods I could eat PWO & leave in my vehicle to eat immediately after? Thanks for the input!

        • Amy Kubal
          April 18, 2012 at 4:41 am

          Maybe some pre-cooked sweet potato or yam or even a packet of baby food sweet potato for the starchy carb piece. For protein you could go with a can or pouch of wild caught tuna/salmon or sardines. Some pre-cooked meat cut into strips for easy eating would also work!

          • Courtney
            April 18, 2012 at 6:18 am

            Awesome I’ll give them a try! Thanks again!

  20. Olga
    September 8, 2012 at 5:51 am

    Hi Kevin:

    In response to your reply:
    “…In my experiences if the glycogen stores are not addressed post workout then we get an increase in cortisol which will also blunt any protein synthesis hormones.”

    I recently re-read Fagin’s book, and he states that protein post workout should also blunt cortisol. Deos anyone have experience with this?

  21. Glutamine Duerk
    October 9, 2012 at 3:10 am

    Hej Rob,

    great post! This will change my strategy in the future.

    /Duerk

Leave a Reply