OK, today is a blog dedicated to the man who helms the Minnesota Vikings. So, while it will be medical in nature, it will still be loosely related to football. I hope Brad Childress reads this and applies some of the findings to the team this coming season.

Am I worthy of writing a scientific-medical related blog entry? Well, I’ve been a licensed drug dealer (see pharmacist) for a quarter of a century now so, yeah, I think I can tackle this.

I’ve been listening to my new favorite podcast at Tri-Talk.com. If you are an endurance athlete, you need to start down loading these podcasts. Tri Talk is not only the #1 triathlon podcast, but now the #4 featured podcast in all of iTunes Sports and Recreation. It is that darn good. Note: Anything in quotes in this blog has been taken from Tri-Talk.

First up for discussion is the dreaded topic of lactic acid. For triathlete’s world wide, Julie Moss is the image often conjured up. Her claim to fame came during the 1982 Hawaii Ironman Triathlon, in which she competed as part of her research for her exercise physiology thesis. At approximately two miles before the finish line, she became severely dehydrated. She staggered and crawled towards the end of the course, only to be passed moments before the finish line by competitor Kathleen McCartney. Her struggle to finish the Ironman was broadcast around the world, and provided inspiration to many to compete in Ironman events.

Not familiar with Moss and her ordeal? Take a peek. It ain’t pretty:

So yeah, one could say lactic acid has a reasonably pessimistic association. As stated on Tri-Talk:

“Most of us, including me, have been taught that a buildup of lactic acid is a bad thing, and that it is the primary cause of having to slow down at high intensities. That lactic acid builds up; the body can’t clear it, and is makes our muscles fatigued. It is even blamed for the soreness of muscles after exercise.�

So, where did the whole lactic acid issue cramp, er, come from? Roughly 100 years ago by a Nobel scientist, Otto Meyerhof. Meyerhof was a German-born physician and biochemist. So you shouldn’t be surprised to learn that one day Meyerhof decided to sever a frog in half and put its bottom half in a jar. Or maybe it was a beer stein. Anyway, he then gave the frog’s leg electric shocks to make the muscles contract, but after a few twitches, the muscles stopped moving. Why did they stop? Meyerhof discovered that they were inundated in lactic acid, and the modern theory on lactic acid was born. Tri-Talk postulated:

“To further understand this, let’s take a quick review of the two primary energy systems: aerobic and anaerobic. Both systems burn carbohydrate in the form of glucose (blood sugar) and glycogen (muscle sugar). The main difference between the two systems is the presence of oxygen–and the end product. Moderate exercise is mostly aerobic, with oxygen; it’s clean burning, so there is no end product. When exercise becomes more intense and the aerobic system can’t provide enough oxygen, the anaerobic system kicks in to provide energy, without oxygen. The end product of anaerobic exercise is lactic acid.�

This theory is under attack and has been something I’ve been tracking since 2005 when it began to be questioned. Let me stress: The basis of lactic acid has not come into the question. Rather, the link between lactic acid and muscle fatigue and soreness has been significantly challenged.

One such study appeared in May, 2006 when George A. Brooks, a professor in the department of integrative biology at the University of California, Berkeley gave an interview with the New York Times. Brooks has been promoting the hypothesis that lactic acid is a fuel supply for muscles, not just poisonous litter from extreme exercise.

“The current understanding by many physiologists, as first proposed by Dr. Brooks, is that muscle cells convert glucose or glycogen to lactic acid, and that the lactic acid is taken up and used as a fuel by mitochondria, the energy factories in muscle cells. Dr. Brooks even found that mitochondria even have a special transporter protein to move the lactic acid into them. In other words, the muscles want to take in that lactic acid as a fuel source, and have evolved with special receptors to do so. Intense training makes a difference because it can make double the mitochondrial mass, therefore increasing the amount of lactic acid that can be absorbed.�

In review, the traditional theory states that as carbohydrate is broken down for fuel, the byproduct is lactic acid. Lactic acid is believed to be a major contributor to muscle fatigue. The innovative theory is that while lactic acid is still a byproduct of carbohydrate, it is cleared away not in the blood, but absorbed by the mitochondria in the muscles. This still explains why elite athletes are able to have very little lactate in their blood at high intensities. It’s not being cleared away in the blood; rather, it’s been sucked up by the muscles like a Hoover.

“One of the problems in accepting this theory is that it left a gaping hole. If lactic acid is not the cause of muscle fatigue, what is? Before we can accept this new lactic acid and muscle fatigue theory, we should have something to replace it.�

Back to the liberal rag that is the New York Times. It recently reported a novel theory to explain muscle exhaustion. Dr. Andrew Marks, principal investigator of the new study from Columbia University, suggests that muscle fatigue comes from calcium leaking from the muscles. That calcium is a critical mineral required for muscle contraction. Less calcium means less muscle contraction, and more muscle fatigue.

“To help confirm this, the researches gave an experimental drug to mice that inhibited the leaking of calcium from the muscles. The mice were able to run 10 to 20 percent longer when using this drug.�

Let’s extrapolate that to potential implications to Adrian Peterson and the team. Let’s say that Adrian is able to run a 30-minute time trial at 6-minute miles, and that is his exhaustion point. Yeah, I know he’s Jesus and would never tire but go along with me.

That means All Day is running 5 miles in that 30 minutes. If he could run 20% longer at the same speed, that would allow Peterson to run 6 minutes longer at that pace before exhaustion, letting him run almost a full 10K at a 6-minute pace. This gives you an idea of the significance of the ability to increase one’s exhaustion point by 10-20%.

This investigational drug is still too dicey for trial on humans, and even if it were permitted by the US Federal Drug Administration, it would undoubtedly be made a banned substance by any given athletic body.

The purpose in passing this along to Coach Childress is not to say “get this drug for your team before they figure out how to test for it!� but rather to share with him the substantiation behind the new theory that calcium loss is behind muscle fatigue as opposed to lactic acid.

On to part two of this discussion for Coach Childress. I want to spend some time looking at whether taking in oxygen can aid and speed recovery. How many times have you seen football players complete long runs and then go back to the bench and breathe oxygen? Does that really help? Tri-Talk helped to asses this:

“In people with normal lung function…breathing oxygen has not been demonstrated to significantly change exercise performance. Based on the oxygen solubility coefficient and the increase in the cardiac output, perhaps a 1-2% increase in the delivery of oxygen occurs, yet few studies support the contention that this therapy helps the athlete. Why is it done? Perhaps because if an athlete who is paid $1,000,000 a year to perform thinks breathing oxygen improves performance, then the best course may be to supply the oxygen, considering no demonstrable harm comes from short-term oxygen therapy.�

Aha! It’s all in their heads! So, as long as the athlete thinks it does, and it causes no detrimental performance, why not let them do it?

Further, if oxygen during exercise does not help out, what about oxygen for recovery? Will you recover faster? Tri-Talk once again broke this down:

“I received a well-written e-mail on this subject from one of our sharp Tri Talk listeners, Michael Phillips, who is a respiratory therapist. He remind me that in terms of muscle soreness and fatigue, it is primarily caused by the buildup of lactic acid and damage to the muscles causing an inflammatory response, often caused by moving up to fast in volume or intensity in training. We’ll focus on the first reason, the buildup of lactic acid, as oxygen would not even theoretically help with muscle damage recovery. Will an increase in oxygen remove lactic acid faster? Lactic acid is the byproduct of CO2 production in the cell. Red blood cells that travel by the cell remove the CO2 and leave behind O2. Less CO2 in the system after exercise therefore means less lactic acid. However, breathing in extra O2 will not remove the CO2 any faster.�

So, Coach Childress, there is no study to support oxygen and recovery where the athlete did not know what the gas was. In cases where the athlete reported improved recovery from oxygen, that athlete knew what the gas was they were taking in.

To sum up oxygen and its use for revitalization, there is no supporting work where the athlete did not know if they were taking in oxygen.

“I think the great sports exercise writer Owen Anderson put it best when he said, “When examined closely, such findings should not be surprising. After all, the post-exercise recovery period is a time frame marked by sub-maximal heart rates and sub-maximal rates of oxygen consumption. In other words, recovery does not require oxygen delivery to be extremely high, as it is during intense exercise. Piling on the oxygen during recovery is like adding another half-cup of water to your goldfish’s tank: the creature already has quite enough water and a little more will not be helpful in any way.�

Maybe Childress should fill those oxygen tanks with helium. Then when Peterson yells, “Hi Mom!� into the camera he can sound like Mickey Mouse.

OK, bad idea.

Coming Saturday: A look back to 1997 when I sat down with then Vikings marketing director, Stew Widdess.

Posted by briankeithmaas@msn.com at March 14, 2008 1:01 AM