1st set (very slow, intense movements)
Push-up to failure
Wide arm pull-up to failure
Squat (two 35 lb weights) to failure
2nd set
Military push-up to failure
Reverse grip narrow-grip pull-up to failure
Squat (two 35 lb weights) to failure
3rd set
Wide arm push-up
Overhang narrow-grip pull-up to failure
Squat (two 35 lb weight) to failure
I haven't had much of a chance to write over the last two weeks. However, I have continued my training and it has definitely been progressing surprisingly quickly considering I'm only working out once a week. The best part of it all is that I have had no muscle cramping or muscle pulls despite the intensity of the workouts.
I want to talk about nutrition. Lately, I've been reading about all things having to do with sugar. It started with a New York Times article about Dr. Robert Lustig, a neuroendocrinologist out of UCSF. He gave a lecture about 6 years ago that became a YouTube sensation. It was a lecture titled "Sugar: The Bitter Truth." In it, he made the argument that sugar, that is sucrose, is metabolized differently from starch or glucose. In fact, it's metabolism, and the problems associated with too much of it in the diet, is akin to alcohol. I've watched the lecture and his follow-up lecture. In addition, I've read a number of review papers by Dr. Lustig. His lectures and papers are heavy on the biochemistry side but I'll attempt to explain exactly what the hell he is talking about. Look at the following picture (taken from Lustig, RH "Fructose: Metabolic, Hedonic and Societal Parallels with Ethanol" J Am Diet. 2010; 110:1307-1321). Just follow the arrows and see how they take you to words such as VLDL, Inflammation, Muscle IR (insulin resistance) and Dyslipidemia. Fructose has the capability of sending these pathways into unchecked overdrive and that is exactly the point.
This is a slide directly from Dr. Lustig's lecture. It's important to understand what sucrose or table sugar actually is.
Sugar is a disaccharide (meaning two sugars linked together) of fructose and glucose. Glucose is used in every single cell in the body. When you are low of the storage form of glucose, glycogen, your body takes fat and protein and makes more glucose in a process called gluconeogenesis. Glucose is the carbohydrate of bread, rice, pasta, etc. Most of the glucose you eat ends up hitting the blood stream, being taken up by cells, and used to make energy. A small percentage of it enters the liver where it is mostly converted to glycogen. Only a very small percentrage becomes pyruvate (see graph above) which then goes into the mitochondria and, via the Krebs cycle, is converted to ATP (the energy of life).
Sucrose (or high fructose corn syrup which is even worse), on the other hand, is quickly broken into fructose and glucose. About 10% of the glucose makes it to the liver. However, nearly 90% of fructose goes to the liver where it is metabolized exclusively in this organ. It's converted into a number of products like glyceraldehyde (aldehydes cause protein cross-linkage and protein damage). In fact, the acetaldehyde metabolite of alcohol is the compound that causes cirrhosis and liver scarring. Fructose, for all intents and purposes, causes the exactly the same scarring by way of glyceraldehyde. If you're having a hard time believing this, just think about this well-known fact: the number one cause of liver cirrhosis is not alcohol but something called non-alcoholic steatohepatitis. It's another way of saying: cirrhosis scarring due to a fatty liver. Check out ethanol metabolism and compare it with fructose. Pretty similar if you ask me:
In medicine, we call any substance that has no metabolic or biologic purpose and is exclusively metabolized by the liver a poison. It's a little tricky to see in the biochemical map above, but fructose is converted into pyruvate bypassing an enzyme called phosphofructokinase (PFK) that is involved in converting glucose into pyruvate. This enzyme is what we call a rate limiting step. That means that it's a major toll booth or bottleneck that slows the whole process down when you get too clogged with the end products (which is ATP). Fructose's ability to bypass this enzyme means that there is no check on the whole process. Fructose is converted to pyruvate which then becomes acetyl-CoA. Acety-CoA generates ATP via the Krebs cycle. When there is too much ATP, citrate, an step in the Krebs Cycle, leaves the mitochondria and is converted directly into fat. It also blocks phosphofructokinase interestingly thus the reason this enzyme is rate limited. However, since fructose bypasses this enzyme, it doesn't really matter. Citrate is converted in stepwise fashion to VLDL and free fatty acids. In other words:
Fructose -->Glyceraldehyde--> Pyruvate --> Citrate --> FAT
Alcohol also very efficiently is converted to acetate which is converted into citrate and hence fat. A lot of people think the carbohydrates in light beer are eliminated. However, most of the calories in regular beer that reach the liver are the same that reach the liver in light beer. Why? Because both types of beer have the same alcohol content and it's the alcohol that is directly converted to fat.
Dr. Lustig also made reference to another physician named Dr. John Yudkin who in 1972 wrote the book "Pure, White and Deadly." I just finished reading this magnificent book. Forty years ago he predicted the inevitable consequences of a diet high in sugar. At the time the biochemical maps as I've outlined them hadn't been discovered fully. He only had epidemiological and animal evidence. To this day, if you as a scientist wanted to study diabetes in rats, you feed them a pure fructose diet to give them obesity and diabetes. In any case, he spent his years trying to discredit the fat theory of cardiovascular disease as the worst falsehood ever to be hoisted upon the American public. It was based upon a study done by an epidemiologist named Dr. Ancel Keys who created the following chart:
However, he chose only 6 countries to be included in his data. What does the data look like when the rest of the countries are added back in? Compare for yourself.
This is a closer view of the real data:
As you can see, Dr. Keys went and cherry-picked his data. I can see why Dr. Yudkin was so frustrated with the medical establishment's insistence on fat as the culprit when in fact there seems to be something else going on. In fact, the real data was published in 1957. You would have thought this data would have discredited Ancel Keys, but current the persistence of low-fat, sugar containing processed foods like yogurt as "heart healthy" means we are still living with his legacy. The USDA and the FDA looked at fat as evil, looked for substitutes (enter vegetable oils), and never looked back. And we're fatter than ever.
A lot of people have luck with lower carbohydrate diets. They cut out bread, pasta and other sources of carbohydrates and seem to have great weight loss results. However, if you have a ham sandwich on white bread or even wheat bread with mustard and cheese, most likely the only component of the sandwich without high fructose corn syrup or sugar is the cheese. Are they giving up glucose in the bread and pasta or is the real benefit coming from eliminating the sugar that is usually in these foods?
Give serious consideration to cutting back on sugar if not outright eliminating it. See how you feel.
No comments:
Post a Comment