Sunday, February 13, 2011

Metabolic Efficiency

Metabolic efficiency can generally be defined as your ability to sustain more work (power, pace, etc.) while using less energy. More specifically ME can be defined as your body's ability to utilize more fat as fuel while sparing your limited amount carbohydrates.

To become more “metabolically efficient” will help you to access more of the 80,000 plus calories you have stored as fat and preserve the less than 2,000 calories available as stored carbohydrates.
Key Points: Training

Key point 1: Low to moderate intensity workouts are a key training component to improving your metabolic efficiency

Long duration and/or more frequent steady state workouts that are at or near the intensity of your Maxfat burn zone, which is about 55-65% of your MaxVO2, will help to optimize your ability to use fat as a fuel and help spare your limited but precious glycogen (i.e., stored carbohydrates).

Estimates are that even while exercising at your max fat burn zone your carbohydrate stores can sustain your effort for only around 5.5 hours before it will become necessary for you to slow down due to depletion problems. Additionally, pushing at intensities that are above that zone can severely shorten that duration potential. Obviously, this information is critically important for long course endurance athletes like Ironman and other ultra-distance athletes, but this concept may also be relevant in helping all athletes and exercisers to burn more fat while training. And this may be critical to recovery and in maximizing your power to weight ratio.

(Note: elite endurance athletes can often burn up to 8 calories per minute at their FatMax while most everyone else will burn less than half that amount).

The renewed focus on the importance of increasing fat utilization (i.e., metabolic efficiency) has been promoted by recent presentations by Registered Dietitian and Exercise Physiologist Bob Seebohar who believes you can “teach your body to burn more fat” and at the same time avoid gastrointestinal (GI) problems that are common with endurance athletes. He has observed that many athletes are not only limiting their potential to use more fat as energy but can actually be lowering their fat use because they are training too hard and consuming too many carbohydrates. This is especially relevant during the lower volume transition and base periods in training programs.

Read Bob Seebohar
http://www.usatriathlon.org/resources/multisport-zone/fuel-station/metabolic-efficiency-training
Sample metabolic efficiency training journey
http://www.usatriathlon.org/resources/multisport-zone/fuel-station/my-metabolic-efficiency-journey

Key Point 2: Increased training volume is the Key to maximizing fat utilization, increasing performance and burning body fat

Another key factor in optimizing endurance performance is your ability to maximize your volume of training by ramping up the frequency, duration and intensity of your training at a rate that you can continue to cope and recover. As long as you are able to adapt to performing more frequent, longer, and more intense workouts you will continue to increase your ability to maximize fat utilization, push up your sustainable pace, and give you an even greater net calorie expenditure. Of course the critical consideration when ramping up your volume is RECOVERY. Generally it takes many phases and even years to lift your training volume up to your potential safely.

Read: Matt Fitzgerald’s Racing Weight
http://www.velopress.com/sample/sample_RW.pdf
How does nutrition fit in the metabolic efficiency equation?

Key Point 3: Nutrition

Seebahor also recommends a periodized approach to eating which includes limiting your carbohydrates especially during your transition and base training periods. During these periods the focus should be on eating fruits, vegetables, lean protein and healthy fats and limiting sugars and grains. Your food intake should adjust according to the volume of your training with carbohydrates only increasing in concentration as training intensity and volume increases.

Read: Paleo Diet for Athletes by Joe Friel and Dr. Loren Cordain
http://www.thepaleodiet.com/paleo_books/forathletes.shtml or Bob Seebahor’s Nutrition Periodization for Athletes
http://www.amazon.com/Nutrition-Periodization-Endurance-Athletes-Traditional/dp/0923521836

In summary:Maximizing your endurance training effects will require walking a delicate line between pushing too hard too frequently which can limit your ability to use fat as a fuel, leading to early plateaus in your endurance fitness. On the other hand the volume in your training will need to be progressed with an appropriate dose of intensity to continue to maximize both fat utilization and sustainable power. Nutrition can play a critical role in helping you adapt to the training cycles necessary to reach your peak fitness. A periodized approach both to your training volume and your fuel intake is critical to your success.
Strategies:• During your base training periods start eating mostly fruits, vegetables, lean protein and healthy fats. Consider a periodized nutrition plan.
• Start Tracking all your exercise and food intake on http://www.trainingpeaks.com/
• Consider tracking your power to weight ratio and metabolic efficiency at a credible human performance testing lab.
o Test your metabolic efficiency on the treadmill, bike or both to evaluate your current ability to burn fat and to determine your max fat burn zone.
o Re-test your metabolic efficiency if the baseline test determined that your fat utilization was limited.
o Test your body composition to evaluate body fat% and lean mass changes.
o The goal with this testing is to set your training parameters (i.e., what pace and heart rate is associated with my max fat level) and to determine if your training and nutrition changes are having the desired effect.
Seebohar refers to the crossover point as the"Metabolic Efficiency Point" which is the intensity where carbohydrates first begin to burn at a greater rate than your fat energy. The goal is to move this point to the right on the graph below so that the Metabolic Efficiency Point will occur at higher pace or power outputs. To determine your individual crossover you’ll need to get tested.

If you have an interest in optimizing your metabolic efficiency the Fit Stop is currently offering an opportunity for you to experiment with some of these concepts by participating in our Metabolic Exercise Profile. This testing will provide the following useful information and tools to help you maximize your endurance potential and a greater ability to decrease your body fat:

• An Exercise Metabolic Assessment to determine your current Maxfat level, aerobic threshold, and cross-over point (where you begin to burn more carbohydrates than fat).
• Determine your metabolic training zones for heart rate, power and pace.
• Receive your own energy expenditure table which will list your calories expenditure rate for carbs and fat at various sub-maximal intensity levels. See sample table at www.fitstop-lab.com/tools/metabolicefficiency.xls
• An exercise physiologist will also help you set-up your training program and tracking system using the Training Peaks platform.
• Re-evaluations will be included at half price.

Contact us at kjnico@fitstop-lab.com or call 760-634-5169

No comments: