Can You Turn Fat into Muscle?

The short answer is no – fat does not get transformed into muscle.     Fat and muscle are two different tissues.    You can increase muscle mass while you decrease fat mass, but fat is not converted into muscle.  In the same way muscle cannot be converted into fat.    Fat is created whenever we take in excess calories from fat, protein, carbohydrate (or alcohol).    In this case the calories ultimately end up being converted to triglyceride and stored in fat cells.

Each molecule of triglyceride (fat) consists of a carbon, hydrogen and oxygen.  To get rid of a single molecule of triglyceride takes many enzymes and biochemical steps to completely oxidize fat.    The complete oxidation of 10 kg (22lbs) of fat requires 29kg of oxygen consumption and the production of 28 kg of carbon dioxide and 11 kg of water (H2O).   The carbon dioxide is excreted by the lungs while the water is excreted as urine, sweat, breath, tears or other bodily fluids.  

Building muscle is a whole different process.     Three key mechanisms are responsible for initiating muscle growth:

Muscle Tension – all forms of resistance training force muscles to create tension to support and move the load.    When enough tension is created causes changes in the chemistry of the muscle allowing for growth factors to be secreted such as mTOR and satellite cell activation.   Tension can come from active tension where muscles actively contract and also from passive tension which is stretching which tends to occur during the lengthening (eccentric) phase of a resistance training exercise.    

Active tension tends to result in muscle fibers becoming wider while passive tension can make them longer.

Muscle Damage – damage to muscle cells causes a release of inflammatory chemicals and immune cells that activate satellite cells to come into action.     This also initiates muscle growth.

Metabolic Stress – When you feel the “burn” or the “pump” when lifting weights, you are feeling the effects of metabolic stress.     Metabolic stress from high levels of anaerobic energy production helps contribute to muscle growth without necessarily increasing the size of the muscle.   This is from the addition of glycogen (multiple glucose units linked together in the muscle), which helps to swell the muscle.     This type of growth is often referred to as “Sarcoplasmic Hypertrophy” and can increase the appearance of larger muscles without increasing muscle strength or the size of muscle fibers.    Increased fiber growth is referred to Myofibrillar Hypertrophy referring to the fact that myofibrils (muscle fibers) and growing.

In summary, for muscle building to occur you must force your muscles to adapt by creating stressors including increase tension, muscle damage, and metabolic stress and then eating properly and resting to allow the muscles to recover and grow.