Achieving Maximum FAT Oxidation By Increasing Total Energy Expenditure

In the previous post, I gave an overview of postabsorptive metabolism, or how the body processes macronutrients on an empty stomach and also during exercise. Here let's delve further into the issue of maximizing FAT oxidation. Studies have compared sedentary people with trained athletes, and have found that going from couch potato to trained athlete increases maximum FAT oxidation significantly, despite both subjects performing exercise of the same intensity.

The literature shows that maximum FAT oxidation occurs at about 63% VO2 MAX, which is equivalent to a decent jog: one where you are breathing heavily, yet can still manage to chat with a partner. VO2 MAX intensity above 63% leads to less FAT oxidation and greater reliance on CHO energy. An untrained man may burn about 10-15 g/h at this pace, while seriously trained athletes can achieve levels of 30-40 g/h at the same VO2 MAX. By combining MNP 100% Muscle with these high levels of FAT oxidation achieved via serious exercise, you have found the most direct path towards improving body recomposition!

Research has illuminated how the body increases FAT Oxidation in response to long term increases in total energy expenditure (TEE). There are several factors, all of them facilitated by the increasing levels of the specific enzymes.

Training Causes Important Changes In Muscle:

1. Increased Capillary Density. This enhanced blood flow increases the ability of muscle to oxidize FAT (and transport nutrients, etc.). As muscle fiber area increases, capillary density increases proportionally.

2. Increased fatty acid entry into mitochondria. This increases respiratory capacity; in untrained subjects, fatty acid uptake by mitochondria is limited by the lactate threshold, thus a ceiling for FAT oxidation is hit. But after heavy training the body adapts and the raises the lactate threshold.
3. Increased size and number of mitochondria (2). Again, this increases the ability of muscle to burn FAT at a higher % of VO2 MAX, which allows maximal FAT oxidation and preserves glycogen stores (this saves more glycogen for high intensity bursts, which is a very beneficial evolutionary adaptation, obviously).
   

These scientific findings explain why, during exercise of the same intensity, fat oxidation is higher in endurance-trained versus sedentary subjects. So let's use this science-based information for motivation. It's great to know that the harder you work, the more the body will helps push you towards Maximum Nutrient Partitioning. The great lesson of health is that by obeying the biology of the body (working hard on diet and exercise), you create the tools you need to achieve your goals. Now that's what I call MNP 100% Muscle.

References (Click On The Links To Download The Entire .pdf File):

1. Regulation of fatty acid oxidation in untrained vs. trained men during exercise. Am J Physiol. 1998 Mar;274(3 Pt 1):E510-5.

2. Adaptations of skeletal muscle to endurance exercise and their metabolic consequences. J Appl Physiol. 1984 Apr;56(4):831-8.

3. Fat metabolism during low-intensity exercise in endurance-trained and untrained men. Am J Physiol. 1994 Dec;267(6 Pt 1):E934-40.

4. Muscle fiber hypertrophy, hyperplasia, and capillary density in college men after resistance training. J Appl Physiol. 1996 Nov;81(5):2004-12.

5. Effects of fatty acids on exercise plus insulin-induced glucose utilization in trained and sedentary subjects. Am J Physiol Endocrinol Metab. 2002 Jan;282(1):E125-31.