Ketogenic for cycling

Discussion in 'Cycling Training' started by SniperX, Mar 26, 2003.

  1. SniperX

    SniperX New Member

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    Anyone knows if a ketogenic diet will be good in cycling?
     
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  2. ric_stern/RST

    ric_stern/RST New Member

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    Ketosis, is neither good for your health, your cycling performance or your social life. Ketosis is the result of a severe lack of carbohydrates and presumably an increase in protein and fat. there's a high protein thread in the nutrition section.

    Ric
     
  3. Duckwah

    Duckwah New Member

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    Keto would have to be the WORST diet for cycling

    fat metabolism is very slow compared to carb metabolism and you would feel awful a very short distance into any ride

    plus as Ric said its dangerous
     
  4. J-MAT

    J-MAT New Member

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    Ketosis is a very dangerous condition for the body to be in. Ketone bodies form in the blood when carbohydrates are restricted, starvation diets, or not utilized due to disease such as diabetes mellitus. When carbs are restricted, the body tries to produce glucose through a process known as gluconeogenesis, literally the "new formation of glucose."

    Unfortunately, this requires that the body catabolize(eat) some muscle protein along with fat to make glucose. The body can do this but the process is much slower than when adequate muscle glycogen is present. That is why when you bonk, you can't maintain the pace. You've run out of glucose, and now your body will start to eat itself in an attempt to maintain the effort, which of course it can't.

    It should be common sense that restricting carbs to the point of going into ketosis is stupid to say the least, not to mention the health and performance loss of your body consuming itself.

    Additionally, ketone bodies are very acidic. This will lower your blood and intracellular PH, causing the same negative perfomance aspects as too much lactic acid accumulation: Heavy breathing and poor performance. Diabetics in full ketoacidosis can be laying in bed and be breathing faster than a rider in a 40 km time trial, due to the very low blood PH (breathing hard is one way the body eliminates acid in the blood). Of course, these patients are in a full blown medical emergency and need immediate medical care.

    It is very foolish and unhealthy for riders to restrict food you body needs. If you feel hungry your body is telling you someting - EAT!!!

    Good Luck!!!
     
  5. SniperX

    SniperX New Member

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    hmm i have tried both the high carb and keto diet and it seems to me that when i was doing the keto i could run on empty for very long ( > 100km) so i was thinking could it be that fat is a much better source of energy than carbs? afterall fats contain much more calories
     
  6. J-MAT

    J-MAT New Member

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    Fat is the preferred fuel source for the body because storing it is easy and it provides the most energy per gram for the for low-moderate intensity day-to-day activities. Fat is very efficient, plus the body can store vitamins and minerals in it. Sleeping, walking, easy rides, etc., can be sustained exclusively on fat alone. View your racing energy requirements as a fire of varying heat and size. Think of fat as a big log that will burn slowly for hours.

    Converting simple (coke) or complex (whole wheat bread) carbs into muscle glycogen is a complicated process and is very time consuming (36-48+ hours). It takes a lot of energy (fat) to power this process, and puts greater demand on the body than storing fat. Since the body had to work so hard to make this premium fuel source, it doesn't like to waste it performing low intensity, "menial" activities. High-intensity riding requires adequate muscle glycogen derived from dietary carbohydrate. Think of muscle glycogen as kindling that will burn fast and hot, but not long lasting.

    A complicated chemical process known as the Krebs cycle is where it all takes place. The end result of the Krebs cycle is the production of ATP (adenosine triphosphate). Blinking your eye requires ATP as does racing. Blinking your eye requires a lot less ATP and can be fueled from fat alone. Racing requires a lot of ATP, and cannot be powered by fat alone due to the complicated and time-consuming pathway it must take to produce energy. Carbs provide rapid energy when needed. The body must consume glycogen to assist this huge demand.

    Using the "fire" analogy, sitting in the pack or riding easy, you have a nice little fire burning. The moment the pace picks up, the size of the fire needs to get a lot bigger/hotter and it needs to do it quickly!!! Putting a big log (fat) on top of a small fire won't give you the instant heat you need. Throwing kindling (carbs) on a small fire will make the fire increase is size and heat right away.

    You might be able to go well on a keto diet at low intesity, but if you restrict dietary carbs (ketogenic diet) you will not have the glycogen needed to go fast when you need to. That's one of the reasons why after 2+ days of hard riding (glycogen depletion), your performance declines, and systemically you feel fatigued. Pro riders in the tour are in a constant state of overtraining/glycogen depletion. If you ask any of them after the first week or so, they will tell you they are tired.

    Any rider who completes a tour will almost always be a much better rider in the long run than one who doesn't. So which is it? Ketosis is bad, but tour overtraining is good? Yes to both!!! 3 week stage races that overtrain a glycogen-depleted rider will take that rider to a much higher fitness level. These riders will lose weight over the 3 weeks for sure, and some of that will be muscle.

    The point to make is they ingest tons of carbs even though their
    bodies won't be able to completely synthesize 100% of the muscle glycogen they need in the short time between stages. Racing is this condition will force the body to consume protein (muscle) so it can burn fat in an attempt to get the fuel (ATP) it needs, but of course it cannot meet these needs 100%, so the riders pace will naturally slow down. It is not possible to produce the same power in a catabolic state as in a recovered, glycogen-restored state. Once recovered from the 3-week effort, they will be stronger though.

    If the big tours were 200 km a day for 3 months instead of 3 weeks, yes someone would be able to do it and win, but the toll on the body would be tremendous. Recovering from something like that could require many months off the bike.

    Power output, max heart rate, and anaerobic threshold are dramatically lowered the more depleted/overtrained you are. The fact that the top G.C. riders can TT well in the last week of a national tour is a testament not only to their physical and mental strength, but their huge recuperative (glycogen restoring) powers as well. Lemond's 15 mile/34mph TT on the last day of the 1989 Tour is a good example. By the way, that effort is still the fastest Tour TT ever!!! You can bet that Lemond ate plenty of carbs the night before!!!

    You say that you were doing well on a keto diet when "empty" for 100 km. My question is why should you be riding on empty for 100 km? I can only guess that everybody wants to lose bodyweight now because Armstrong got cancer. It's definately effected the pro ranks. One guy gets a life threatening illness and loses weight, so everybody else has to jeapordize their health to keep up?

    It wouldn't surprise me that someday a guy will have his appendix or other kidney removed to save weight. This is not a step in the right direction. Other pros don't have to lose weight in order to beat Armstrong - they must train better than he does, and nobody seems to want to. Jan Ullrich is stronger and faster than Armstrong but he doesn't like cycling as much as Lance does.

    The real issue, is damage to the body. Short-term overtraining like stage racing can make you stronger and faster only if you recover properly. However, 3-week stage races are not the norm in the racing season, one day races are. Ketosis is damaging to the body at rest, let alone while pushing hard. A Keto diet would be very damaging if practiced on a long term basis. Lose weight (fat) if you must, but don't hold back on the carbs!!!
     
  7. SniperX

    SniperX New Member

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    i went on empty cos i though that the energy one gets is from what he or she ate the night before? Can food taken bout an hour or do before a ride increase one's performance?
     
  8. J-MAT

    J-MAT New Member

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    Yes. Eat no sooner than an hour before your ride, 2-3 hours if racing or an important ride. Digesting food takes bloodflow and energy that could be used for your legs, that's why you want to wait. Also, your insulin levels will be high after eating. Riding too soon with high insulin can actually cause you to burn more muscle glycogen rather than spare it. Liquid carbs like Coke, Gatorade, and gels, are more easily digested than food. Longer rides (3+ hours) require that you eat on the bike. Liquids and gels are best, since swallowing food is more difficult. Let preference be your guide here.

    There is a lag time between the time you eat or drink and actually getting the glucose to the working muscles. Again, liquids are processed faster. The idea is to periodically eat or drink at regular intervals, even if you are not hungry or thirsty. Doing this will ensure you have a constant, steady release of glucose to the working muscles.

    I can only imagine how much more enjoyable your rides will be if you eat before a ride and during longer ones. Few things suck more than having to turn the cranks over for two hours after you have cracked.

    Good luck!!!
     
  9. SniperX

    SniperX New Member

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    But after I stopped the ketogenic diet ... I put on at least 3 kg of weight ( predicted to be muscle and waterweight perhaps).. wont this weight drag me down in terms of performance even though i have the carbs back?
     
  10. J-MAT

    J-MAT New Member

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    You must understand that a keto diet is not sustainable or healthy for anyone, athlete or not. You will lose weight in the short term, but your body will overcompensate by storing tons of muscle glycogen ( and 3x the water to go with it). This is the classic "carbo-loading" marathon runners often talk about.

    Carbo-loading is not practical for serious endurance athletes, because day-to-day training requires carbs, and the only way to have glycogen is to eat carbs every day. You don't tend to store as much if you eat carbs daily, rather than eating them after you have starved yourself (keto). The effects of carbo loading are reduced if you eat a normal, high carb cyclist diet.

    The fact you packed on 3+ kg is not surprising at all. The difference between being well loaded with glycogen and being depleted is several pounds.

    Your dilemma: Extra bodyweight and cycling performance. Weight is only important when climbing. That's why bigger riders tend to go faster on the flats and slower on climbs (generally). Extra bodyweight helps to turn bigger gears on the flats, but becomes a liabililty in the hills. High performance riding requires carbs period. There is no way around this.

    If you a hollywood celebrity and need to lose weight for a movie role, riding 100 miles a day for 2-3 weeks on a keto diet would be good. Not so for a cyclist who wants to be healthy and ride well.

    good luck!!!
     
  11. SniperX

    SniperX New Member

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    hmm lets say if i were to deplete myself of carbs and do a carb load before a race will my performance be better than if i were to just do a normal high carb diet as usual ?
     
  12. ric_stern/RST

    ric_stern/RST New Member

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    If you're a racing cyclist, you'll go better if you eat a moderate to high carbohydrate diet on a daily basis. Fairly specific recommendations of carb intake can be suggested depending on daily activity levels.

    The purpose of training is to get fit (defined as in increase in LT, VO2max, and peak power) for racing so that you do better. Even at relatively low levels of intensity (e.g., several hours of endurance training) the majority (50% +) of your energy is derived from carbohydrates.

    At higher intensities, practically all your energy is derived from carbohydrates.

    Thus, to get fitter you need to train fairly rigourously, and to fuel your body you need carbohydrates. If you consume a ketogenic type diet, you will be forced to train slower/less power than if you had an optimum amount of carbohydrates. By training at a lower power you won't get very fit (you might even loose fitness) and thus, you won't be very good at racing.

    Accordingly, keep your carb intake moderate to high (if you train daily, or almost daily you'll need a minimum of 6grams carb per kg body mass, i.e., a 70 kg person needs a minimum of 420 g carb per day).

    Ric
     
  13. SniperX

    SniperX New Member

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    oh ok how bout carb depleting n carb loading b4 a race? Will that be better than just folloing a high carb diet prior to race?
     
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