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triglycerides and running? (Read 860 times)

TrailSurfer


Husband and father of 4

    This is a little scientific / medical, but my academic curiosity is coming out. So, I read an article about triglycerides recently and it got me thinking. http://health.msn.com/health-topics/cholesterol/articlepage.aspx?cp-documentid=100080415 There are circumstances in which these unstable fats can work against us in something they call metabolic syndrome or excessive amounts can inflame the pancreas. "Metabolic syndrome is the combination of high blood pressure, high blood sugar, too much fat around the waist, low HDL ("good") cholesterol, and high triglycerides. This syndrome does increase your risk for heart disease as well as for diabetes and stroke." They say "triglycerides are a major source of energy in the body." As I understand it, all excess calories are converted to these little buggers -- protein & carbs included. So here are the questions: In healthy athletes who carbo-load the day before are they basically increasing their triglycerides? If so, are triglycerides the primary source of energy during a long run?
    Find the fun.
      I'm no expert, but I think since your muscles need glucose to work, your body goes looking for glucose as the fuel. As you run, the body uses the most available glucose - what's in your blood from what you've been eating. Then the the glucose in your fat cells are used, then the glycogen in your liver is used. (I think) Metabolic syndrome is just "a collection of conditions". It isn't a specific disease and high blood pressure and high lipid (fat) levels all need to be treated. Each of the conditions on their own increases the risk of cardiovascular disease, especially diabetes (high blood sugar). The right level of exercise helps to improve or eliminate all the conditions in most cases. My triglyceride level dropped 50% after I started running (and it wasn't really high to begin with). Of all the lipids in my blood, that's the one that dropped the most. Eat good carbs in a balanced way and maintain a healthy weight - that's all you need to do. IMHO

      Suffering Benefiting from mature onset exercise addiction and low aerobic endorphin release threshold. Hoping there is no cure.


      The Greatest of All Time

        During aerobic exercise the body burns a combination of glucose and fat. The ratio is a direct function of heart rate. The higher you get towards your max heart rate the more glucose is metabolized and less fat. This is why so many exercise 'experts' suggested keeping your heart rate low during exercise since more fat would be burned as fuel. While this is true it ignores the fact that at higher heart rates you burn more total calories overall, so although your carb to fat ratio might be higher, you may burn more fat. I remember a chart in The Lore of Running that showed how the ratio changed as heart rate increased. The metabolization of stored body fat is not as efficient as glucose, but more efficient than protein metabolization. Glycogen stored in the liver and muscle is converted to glucose and then used in the krebs cycle to produce ATP...blah blah blah. Essentially the energy is stored in the phosphate bonds of ATP and you have to have glucose to make ATP. Triglycerides is the chemical form of stored fat, primarily in adipose tissue. They are actually referred to as triglycerols, and are basically glycerol molecules that have three fatty acid molecules attached. There are more biochemical steps to break this molecule down into glucose as opposed to glycogen. You also have to have oxygen present to utilize fat stores. Hypothetically, if you deplete all of your glycogen stores in the liver and muscles, then pretty much all carbs you intake will be converted to glycogen and your stores replenished. Any excess can be converted to triglycerides and stored as fat in adipose tissue. A typical human has enough glycogen stores to last 2-3 hours, which is why so many people hit the wall at mile 20 or so during a marathon. Your mind gets foggy too because your liver provides the glycogen to your brain and so when liver glycogen runs low you lose some brain funtion on some level. To answer your questions: carbo loading typically guarantees that your muscle and liver glycogen will be topped off at the start of a race, anything extra likely gets converted to fat and stored. And assuming your long run pace is slow enough that your heart rate is about 60% of max, then fat would be the primary source of fuel.
        all you touch and all you see, is all your life will ever be

        Obesity is a disease. Yes, a disease where nothing tastes bad...except salads.
        TrailSurfer


        Husband and father of 4

          Thanks ruru and ms. I appreciate the insights. That explains a few things I was curious about. An ultramarathon would be an interesting balance between nutrition, metabolism and exercise. This year I am only focusing on middle distance stuff, but intend to bump it up next year. So far I haven't run or swam for more than 2 hours or bonked, but I am curious about the condition, pushing through it and recovering from it. ms: I have to ask you about your title "gaijin samurai". Are you a martial artist, do you have a cultural interest in Japan or none of the above?
          Find the fun.


          The Greatest of All Time

            ms: I have to ask you about your title "gaijin samurai". Are you a martial artist, do you have a cultural interest in Japan or none of the above?
            Funny you should ask. I trained in Tae Kwon Do for a couple of years back in 1995 and loved it. I would love to study Kung Fu and may someday. My avatar picture was taken in Kyoto, Japan December 2007. My wife is Japanese but has been in the US since age 2. Her parents are the only members of her family that live here, so we all went to Japan over Christmas so I could meet everyone. I loved it and did not want to leave. We stayed in Tokyo, Hiroshima, Kyoto, Odawara, and Shinagawa. If I could transfer my law license to Japan, and of course spoke better Japanese, I would move in a minute. But my wife, although Japanese, prefers the US and would never want to live there.
            all you touch and all you see, is all your life will ever be

            Obesity is a disease. Yes, a disease where nothing tastes bad...except salads.
            Trent


            Good Bad & The Monkey

              What mschantz said. Plus this. Every pound of fat provides you about 4500 kilocalories of energy. That is enough to propel most people 30-50 miles of running at a "fat burning" effort. A 150 lb person who has a 10% body fat percentage (which is very very low, and folks with metabolic syndrome tend to have 30+% body fat) will have 15 lbs of fat, which is enough to propel them 450-750 miles of running. You need not worry. Even the thinnest of runners have plenty of fat to propel them.
              TrailSurfer


              Husband and father of 4

                Thanks Trent. That was some good info. Mschantz, you have an interesting backgrand and have had some very cool opportunities. If I could afford it I would take my family to live in Japan for a while. Thanks for sharing that. There are a few asian cultures I find very interesting.
                Find the fun.
                  Oral glucose ingestion increases endurance capacity in normal and diabetic (type I) humans http://jap.physiology.org/cgi/content/full/83/2/608