Durk Pearson & Sandy Shaw®

Keep Going . . . and Going . . . and Going

Interview on Supporting Your Endurance

The first nutritional supplement to come out of Durk & Sandy's laboratory back in the 1970's was then, as it remains now, prescient of what food will evolve into in the future. The drink to consume while reading this article is (or should be) a formulation intended to increase the materials your body uses in the Krebs cycle. As is said of the Energizer Bunny, theoretically it should keep you going . . . and going . . . and going . . . and going . . .


WILL: What's the story behind your drink mix intended to support the Krebs cycle?

DURK: It is actually one of our earlier formulations which, like many of our other formulations, we designed because we had a problem. In this case, it was back in the mid-to-late '70s. We were moving out of a house that we'd lived in for years. We'd been renting it, the landlord wanted to sell it and we didn't want to buy it.

SANDY: And like any other place that we lived in, we'd accumulated tons and tons of materials, lots and lots of books, and journals, and equipment.

DURK: And tons and tons is literal, not figurative. There were many tons of materials.

SANDY: But we had only ourselves to move all that stuff to the new house. Fortunately the new house wasn't a long distance away, but nevertheless it was an incredible job that faced us.

DURK: The house we were moving out of was a two story house, up on a hill, and we had to carry everything down the stairs. The house we were moving into also was a two story. I took a couple of weeks off work as vacation time and we started moving the stuff. We felt really tired at the end of the first day, and at the end of the second day we felt absolutely ghastly. At the start of the third day we knew we weren't going to get the job done - not in two weeks, or three weeks, or even five weeks, at the rate we were degenerating. In simple terms of our muscular ability to pick stuff up, carry it down the stairs, load it into the truck, drive it over to the other house, and carry it up the new stairs, it was just too much.

SANDY: So we started thinking about how energy is generated in the mitochondria, the basic energy factory of the cell. This is where the Krebs cycle takes place. We thought that if we could come up with a supplement that increased the materials used in the Krebs cycle, then we might end up with more energy - through supporting production of the universal energy molecule ATP - and possibly be able to do a lot more work.

DURK: Well, fortunately we had everything we needed on hand to make up the first version of our drink mix. The Krebs cycle, also known as oxidative metabolism or the citric acid cycle is where you get most of your aerobic energy. We made the stuff up on the third day of the move, and by golly at the end of the third day we felt pretty good. At the end of the fourth day we felt better, and every day from then on was even easier. We were moving increasingly more stuff every day and we weren't collapsing the way we had before. In fact, we actually got everything moved out.

SANDY: Yeah. It was an incredible, absolutely mind-boggling job. And while the formula didn't make the move any more fun, at the end of each day we didn't feel as wiped out as we had at the beginning of the move. It became possible for us to keep on going, as long as we needed in order to complete the job.

DURK: You could just keep going.

WILL: Is the effect accumulative? Does it keep your energy production high?

DURK: While you're providing the proper substrates and doing a lot of exercise, your body will respond by making more enzymes that utilize those substrates. If you're limited in the amount of substrates you have in the Krebs cycle, making more enzymes isn't going to do the job for you. For example, if you have an enzyme that requires vitamin B5 as a cofactor - like acetyl coenzyme A - and you don't have enough vitamin B5, there's no point in making more of that enzyme. Because without the B5, it doesn't work.

So what we found was that over the next two weeks, in fact, we got stronger and stronger and stronger. Our strength seemed accumulative. Not so much strength in the sense of how much weight we could lift, but endurance-type strength. You know, how many times could we go up and down those stairs with armloads of journals every day.

WILL: Is it possible that your cells could be operating like a battery's memory, effectively fatiguing and then registering full at less than capacity? Once you push energy to the hilt beyond that point of limited capacity, full becomes fuller than it was before in terms of the amount of energy actually produced, stored and utilized by yourselves.

DURK: Yes. Exercise is well known for increasing your ability to do more oxidative metabolism. The more endurance-type exercise you do, the more you are able to do.

SANDY: Exactly. Yet exercise doesn't provide you with the substrates that are required. Many of the chemicals that are used as raw materials by your body for various physiological processes can be manufactured in your body, but not necessarily all. Under peak effort you may not be able to make as much as you need. But of all the vitamins, minerals and organic fruit acids that we've put into the formula, not many can be manufactured in our bodies.

DURK: You can manufacture the citric, malic and the fumaric acids which are all parts of the Krebs cycle. But normally these just go around and around and around the cycle, acting as energy carriers. Your body is not really required to make a whole lot of these, but if all of a sudden you're doing a lot more aerobic exercise than you're used to doing, you need to be able to make more. Yet you may not have the capability of immediately cranking out as much of the stuff as you now need for the new and higher metabolic demand. And that's why we provide these materials exogenously in our formula.

WILL: Do you get any kind of mood altering effects from the formula?

SANDY: When we use it, we don't feel any different and there isn't any stimulating effect.

DURK: There's no psychoactive effect. This isn't like phenylalanine or caffeine, where you get a feeling from taking it. The drink just enabled us to go on hour after hour after hour after hour carting stuff.

SANDY: That really impressed us, because I don't know what would have happened if we hadn't come up with the formulation. We probably would have had to hire some people to help us move, and we would've been just that much poorer, to say nothing of being even more disorganized.

WILL: Because some of the vitamins in your drink mix have very short half lives in the body, wouldn't it be necessary to keep the supply of them continually replenished, especially when utilizing them in the production of this kind of energy?

DURK: Yes. That's one of the reasons we put this in the form of a drink rather than in capsule form. When a person's exercising, naturally they're going to be drinking a lot.

WILL: I use all your phenylalanine formulations in different contexts - yet I still find an enormous value to the Krebs cycle support formula, especially in the evening when I want my body to go on but not indefinitely. I use it when I just want an added boost and still be able to end my day at a specific point. If I have a phenylalanine drink in the evening I get to sleep much later than I want to.

DURK: The stimulation from noradrenaline and caffeine will keep you going. There's no way around it. But, the Krebs cycle doesn't just maintain healthy brain function. It also supports your mitochondria.

WILL: If I'm working, the Krebs cycle drink seems to give me physical energy to sustain myself. I don't have to worry about my body being fatigued.

DURK: In fact, it also provides energy for your brain. But unless you're low on mental energy, you're not likely to notice any sort of a lift. After all, your brain has a higher specific metabolic rate than any other tissue in your body. Your brain burns fuel in the mitochondria to make energy just like your muscles do.

SANDY: It is really a simple idea, but like all our other formulas we were very careful about putting in necessary cofactors that are required in order to maximize utilization of the Krebs cycle. Without those additional cofactors, you might not really get full benefit of the Krebs cycle biochemicals.

DURK: With our more current knowledge of mitochondria, we have made some adjustments in the formulation, mostly in the quantities of items that are required to oxidize and phosphorylate a mitochondrial-type cycle. We've added hesperidin and quercetin because a lot of people are going to be engaged in vigorous aerobic physical activity. Exercise can increase oxidative damage. One of the most interesting things about quercetin is reported in a paper that shows that quercetin prevents single-strand DNA breakage due to free radicals by way of its ability to chelate loose iron. Loose iron is a very, very powerful free radical catalyst. It can increase oxidative damage.

SANDY: Preventing the DNA damage in this study didn't turn out to be due to the antioxidant properties of quercetin but due to its iron chelating property, and that is very interesting.

DURK: And anybody that does extended intense aerobic exercise is going to suffer some muscle fiber damage. Myoglobin is going to be leaking out of damaged muscle fibers, and when that breaks down it releases iron. Hemoglobin is going to be leaking out of damaged capillaries, and when that breaks down it also releases iron.

So we thought, "We really need an effective iron chelator here that isn't a xenobiotic (foreign to the body)." Quercetin fills that bill. It's been part of animal diets for hundreds of millions of years and the bugs have been pretty well worked out of its metabolism. So we put in quercetin as an iron chelating agent to help protect people from the inevitable iron leakage that occurs with heavy, sustained, or prolonged exercise.

WILL: That's so interesting. I saw a paper recently about the role of iron in otosclerosis. This paper suggested that various bioflavonoids, and particularly quercetin, can be helpful for this kind of degenerative deafness.

DURK: As I mentioned, iron is a very, very powerful free radical catalyst. Even as little as few parts per billion of loose iron can cause a lot of damage.

We have also added vitamin B2 and vitamin B3. They are essential for making the flavoproteins and flavonucleotides that are part of mitochondrial oxidative metabolism.

SANDY: Anybody who works as hard as we do needs to put out a lot of energy every day.

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