I bet you know more about the pressure in your bike tire than you know about your fuel efficiency.

How many calories of glycogen can you store in your body ... 1,800, 2,000, more, less?  No matter how much you believe in "Carbo Loading" you can only store so many carbs. The rest is converted to fat. How many calories of fat is stored in your body? At 3% body fat... 10,000, 8% body fat... 15,000 to 20,000, more, less? 

What is my point about carbs and fats?  Well, I am getting requests from athletes for metabolic testing to determine their fuel efficiency.  So,  I want to share a bit of information about one client in particular. Actually there is nothing out of the ordinary about this client. He was concerned about his nutrition and was wondering if he was doing everything within his purview to meet his goals for the upcoming race season.

This client is a multisport athlete training for an Ironman who came to see me for a VO2/VCO2, metabolic test in mid December. Before the test, I asked him a range of basic questions that he and I would analyze upon the results of the test.  I asked my client what was his goal pace on the bike portion of the IM?  The athlete said to average 17-18 mph.  Then I wanted to know his heart rate at this goal pace and he informed me to be approximately 138-141 bpm. 

Then I performed the metabolic test for the client on his bike.  After reviewing the metabolic test results, I found the client was using approximately 900 (906 actually) calories per hour at a heart rate of 140 bpm (18 mph). Also, his RER was .86 which meant the client was using 47% or 423 calories of stored fat and 53% or 477 calories of carbohydrate per hour at 140 bpm (18mph).  From this information, it was easily determined that the client was a sugar burner and not a fat burner. 

Also, with the above information I was able to calculate my athlete's total energy demands just for the bike portion for the IM event. My client was going to be on the bike for approximately 6.5 hours at 18 mph (even longer if at 17 mph).  This means he was going to burn a minimum of 3,100 calories of carbohydrate and 2,750 calories of body fat. 

My next question to my client was in regards to his nutrition just for the bike portion since no one consumes calories on the swim and not very many calories are consumed during the run.  My client said, "I consume approximately 240 calories per hour of my energy supplement without having G.I. problems."  This was a total of 1,560 calories to be consumed while on the bike.  So my client was going to burn a minimum of 3,100 calories of carbohydrate and consume a total of 1,560 calories. Therefore during the bike event he was ending up with approximately 1,540 calories of stored carbohydrate. That is just for the bike portion.  But, how many calories were going to be used for the swim, 500, 600, more? So it is easy to estimate that my client could run out of energy early during the run portion of the race based on my client's body type. 

My client's body fat percentage was approximately 10%. A conservative estimate of stored energy (less fat and more glycogen) for my client would be approximately 20,000 calories of body fat and 2,500 calories of carbohydrate stores.  Okay, so what you ask? Well, since we have more fat stores it would be a good thing to use more fats and less carbs, right? Unfortunately most energy supplement companies would prefer you use more carbohydrates.

It is commom to see athletes walking during the run portion of the IM.  What can these athletes do? Slow down to conserve energy? Possibly. Eat more? Possibly. Eat more without GI problems? Not likely. Another option is to improve metabolic efficiency.  

There are three primary factors that impact metabolics. These are genetics, nutrition, and training. We cannot do anything about genetics, but we can certainly focus on our nutrition and training to be more efficient. 

NOTE: Below is a protocol I recommend for metaboilic efficiency during base training... not the race season. To learn more about these protocols check out Bob Seebohar's book.

My advice for my client was to eat more foods with a lower glycemic index and train at lower intensity levels to tap into his fat stores, improve aerobic capacity, etc.  While training, my client was only allowed to drink pure water for swim, bike, run, and cross training activities under three hours and high glycemic energy supplements were not allowed.  Thirty to 45 minutes prior to training he would consume one serving of Generation UCAN. Also if the bike rides were longer that 3 hours the client could have one serving of UCAN every 90 minutes while riding at very low intensity levels in zone 1 and low zone 2. Since my client just completed a metabolic test he had his exact training zones established. After my client completed training he would take the UCAN recovery drink. To learn more about Generation UCAN check out Dr. Volek's white paper on Super Starch.

After 6 weeks of following my suggestions I scheduled my client to come back for a follow up test. Typically, I see vast improvements within four weeks, but since the client was following this protocol over the Christmas holiday I wanted to extend the time for a retest. It made no sense in having the client not enjoy the holidays.  

The follow up test showed very good improvements for my client. First, his heart rate at goal pace to maintain 18 mph was lower by an average of 3 bpm from 138-141 bpm to 135-138 bpm, this was most likely due to the long and low intense rides.  At the same goal pace of 18 mph my client's total calories were slightly higher at 916 calories utililized per hour.  But his RER was lower at .82 (.86 previously). At an RER of .82 which identified the percent of cabohydrate used is 40% or 360 calories of carbs versus before my client was using 53% carbs or 477 calories of carbohydrate. His fat burning percentage was up from 46% (423 calories of fat) to 60% (540 fat calories).  This is nearly a 20% improvement in metabolic efficiency.

My primary point for this blog post is we have more available calories for energy from fat than we have from carbohydrates. My second point is most athletes can be more efficient in utilizing available fat stores for energy if they know.  My third point is "Carbo Loading" is counter productive for most athletes.

If you are interested in learning more about metabolic efficiency please contact me.  As you can tell within the article I am pitching UCAN pretty heavily, so, I am offering a 15% discount on all online orders of Generation UCAN, so use the following link if you are not in the Southern Pines Area: http://www.generationucan.com/velosmart/

Oh, and my final point is tire pressure is important, but you should also know how much fuel you have in your tank.