Avoid the Bonk

Richard Knox/NPR

Ben Rapoport takes Erin Wyner's pulse as she runs on a treadmill to determine how many carbohydrates she should eat to run a successful marathon.

Running Endurance Calculator

Use Ben Rapoport's mathematical formula [http://endurancecalculator.com] to calculate your own endurance potential and how much carbo-loading you should do before a race. From Richard Know: For those of you who've had trouble accessing the calculator: Install an updated version of Java.

October 24, 2010

About 200,000 Americans will run marathons this year, and by some estimates about 4 out of 10 of them will bonk. That's runner-speak for "hitting the wall," which is what happens when a long-distance runner runs out of gas, metabolically speaking.

Hitting The Wall

Ben Rapoport hit the wall while running the New York City Marathon five years ago. Here's how he describes it: "Somewhere in the Bronx, I started to feel like I couldn't keep up the pace," he says. "It was awful. I couldn't make my legs run any faster. And when I tried, it was very painful."

Rapoport is getting a Ph.D. in electrical engineering this year at MIT. He also happens to be a Harvard medical student who plans to be a brain surgeon. You might say he's pretty driven. So he decided to apply his brain to the problem of hitting the wall. It's all about carbohydrates, he says.

What Happens

"When an athlete hits the wall, [he or she is] essentially running out of carbohydrates in the leg muscles and in the liver," Rapoport says. "So when you bring the carbohydrate fuel tank to empty, the body is forced then to metabolize fat rather than carbohydrates."

Fat is a much less efficient fuel than carbohydrate. It takes more oxygen to burn. So an athlete needs to pump more oxygen to the muscles to keep going. As a result, the athlete needs to slow down dramatically.

There are all sorts of recipes to avoid running out of carbohydrates. They involve "carbo-loading" — eating a lot of rice and pasta and other carbs before the race. There are also protocols for how to time these carbo pigouts to maximize the amount of carbohydrate that gets stored just where it's needed: in the legs.

How To Avoid The Wall

But Rapoport is a precise guy. He wanted to quantify just how many carbo calories a particular runner is capable of storing, and how much he or she would need to run a marathon at a particular pace.

Running Endurance Calculator

Use Ben Rapoport's mathematical formula to calculate your own endurance potential and how much carbo-loading you should do before a race. His formula occupies eight pages in a scientific paper just published in a journal called Public Library of Science (PLoS) Computational Biology.

Understanding Rapoport's formula requires an advanced degree. But in principle it's pretty straightforward — and accessible to any runner interested in finding the answers to two questions:

1. How can I avoid hitting the wall?

2. How fast a marathon could I potentially run?

To illustrate how Rapoport's formula works, I recruited a young marathoner, Erin Wyner. She met Rapoport and me at an MIT gym. Wyner, 29, says she just completed her eighth marathon with a time of 3:08:06. "That's an excellent time!" Rapoport says. "Have you ever hit the wall?"

"I have crashed and burned and hit the wall in my first marathon," she replies. "It was a mindless struggle, a death march to the end." (You have to take such statements from dedicated marathoners with a grain of salt. In fact, she finished that race with the enviable time of 3:35. But to her that was a disaster.)

How The Formula Works

First, Rapoport has to determine Wyner's maximal oxygen uptake. The technical term is VO2-max. There are fancy methods for determining a person's VO2-max, but Rapoport says a good-enough estimate can be derived from clocking an individual's heart rate at rest and while exercising. Wyner's resting pulse is 63 beats per minute. After she runs on a treadmill for a few minutes, Rapaport measures it again — 120 bpm running at 6.1 miles per hour.

Next he asks her weight — 100 pounds. Knowing her weight allows him to estimate how many carbs her liver and leg muscles can store.

Rapoport plugs all of the numbers into his computer and comes up with an answer that impresses Wyner. "It seems that you're capable at full carbohydrate loading of running a 2:44 marathon," he says.

"Wow!" she responds. "I'm surprised! I may never live up to it, but it's very intriguing. It's out there for me!"

To run her best time — and avoid bonking — Rapoport tells Wyner she'll need to stoke up before the race with 1,900 calories worth of carbs. And of course, she'll need a lot more training, not to mention that hard-to-quantify quality called grit.

Rapoport's formula isn't just for elite athletes, he says. Any long-distance runner can use it. "And," he says, "you'd better believe I'm plugging my numbers into that formula to know how many calories of carbohydrates to load before the race."

The race he's talking about is the New York City Marathon on Nov. 7 — the one he plans to run in 2:50.

FOR MORE INFORMATION ON HEALTHY CARBS & PRODUCTS BASED ON RESEARCH THAT HAS SUPPORTED OLYMPIANS FOR YEARS, CONTACT:

Heather Wilson, Shaklee Sr. Director

404.592.4186

http://www.betterhealthin31days.com/gofit4life/kecd/SportsNutrition

Soy and Boys

Here's a great piece by Dr. Stephen Chaney on the topic of "Soy and Boys."

You've probably seen some of those web sites talking about the dangers of soy - or read newsletters based on the information in those web sites.

If you believed those websites you would think that soy protein products were some sort of evil plot to undermine the health of the American public.

In my past e-newsletters I've talked about some of the distortions and misinformation found in those sites, but today I'd like to address a new topic - the effect of soy on guys.

The anti-soy web sites claim that the weak estrogenic effect of soy isoflavones can cause feminization of boys and weaken men's sexual drive and reproductive ability (Evidently, someone forgot to tell the Chinese about that last one!).

Chemically speaking that is nonsense because testosterone is structurally very similar to estrogen. The soy isoflavones resemble natural testosterone just as much as they resemble natural estrogen - which is probably why some studies show that soy isoflavones slow the increase in PSA levels for men with prostate cancer.

The claims found in the anti-soy sites are primarily based on animal studies, but that is misleading because mice don't metabolize the soy isoflavones in the same way that humans do.

So let's ask what studies with humans actually show. Two recently published studies have looked at the effects of isoflavones and isoflavone-containing soy protein in men. Both were meta-analyses - which means that they analyzed multiple previously published double-blind, placebo-controlled clinical trials. This approach increases the statistical power of the conclusions by smoothing out some of the natural variation seen in individual studies.

The first study (Hamilton-Reeves et al, Fertil. Steril., June 11, E-pub ahead of print, 2009) combined the results of 15 clinical trials and showed that soy isoflavones and isoflavone-containing soy protein intake had no effect on:

-total and free testosterone
-sex hormone binding globulin (a protein that binds to, and stabilizes, testosterone in the bloodstream
-free androgen index (FAI) - an index of all of the hormones in the bloodstream that have masculinization effects (Yes, guys - it's not just testosterone that makes us who we are).

The second study (Messina, Fertil. Steril., 93: 2095-2104, 2010) combined the results of 9 clinical trials and showed that soy isoflavones and isoflavone-containing soy protein consumption had no effect on:

-total or free testosterone levels
-circulating estrogen levels (Yes, guys - we do make some estrogen)
-sperm or semen parameters (Some guys might argue that this is the bottom line).
So the definitive results are in and, once again the Emperors (the doctors writing the anti-soy web sites) have been shown to have no clothes.

To Your Health!
Dr. Stephen G Chaney

P.S. The Wilson family drinks soy shakes daily...all 5 of us! I can tell when we miss a day (it's rare) because we are all a little less stabilized, have a little less "zip," and the boys are a little more whiney! Thank God for Energizing Soy Protein... a biologically complete, super-bioavailable, clean protein source!

Not All Vitamins Are The Same...

Diane Petoskey, M.S.N.D. shares why she has found Shaklee nutritional supplements to be the best on the market. If you want results, the buck stops here!

When you deal with vitamins, you have to understand that if you're going to get your body balanced, you've got to do it with food or food based supplements. For the last 15 years that I've been doing my research in nutrition and working with people. I have had the opportunity to examine many, many different brands on the market and one of the things that I've been very aware of is that you can't trust the labels. A label can say that a product is natural or organic (I love that word) and by law, all the companies have to do is put 5% natural product in that to call it "natural". Now, the natural part could be a filler, or a binder; it doesn't even have to be part of the actual vitamin itself. So be aware that you could be buying a 95% synthetic vitamin, even if it is labeled "natural" and is very expensive.

Over the years I have had great experience and really good luck with Shaklee brand vitamins; they are the closest thing to the food source that we can get. When you take this particular brand of vitamins, you are taking vitamins that are prepared without changing the natural ratio in which vitamins naturally occur in the food.

A good example of how it works is with B vitamins. Many people that I work with around the country will say, "Yeah, I'm taking a high potency B-complex" or "I'm taking a B-50 or a B-100." When you look at the label of those B vitamins you'll see that there's 50 mg of all the Bs or 100 mg or let's say 30 mg of all those B's. Now that is not the way B vitamins occur in nature. If you take yeast or rice bran and break it down, look at the B vitamins (I have) you see that the natural ratio might be 1.2 mg of B1 to .02 mg of B2 to 30 mg of B3. Do you see what I mean? It doesn't all occur even all the way down the line and the only way that those vitamins can be in those proportions – 50 of each, or 100 of each – is if they are made that way, that means those are man made.

Well, your body was designed to assimilate B vitamins in their natural ratio, the way they occurred in food. In my opinion, the only logical way to take these nutrients to help your body become balanced is to take them in the natural form and that's what Shaklee Corporation does. They don't mix it up or change it; they just leave it the way they find it. Their processing system is the best way of any company I've ever found. They don't heat, harden or change them in any way. I really do feel that you'll get the best results with Shaklee vitamins.

Diane Petoskey, M.S.N.D.

Diane is a nationally known Nutritionist. She has been a practitioner in the field of nutritional medicine, a researcher and a lecturer for the past 20 years. Her education includes Nutrition, Herbology, Aromatherapy and Chinese medicine.