Mitochondria are the power plants of cells. Their primary role is to convert the nutrients we eat into energy – specifically through the production of adenosine triphosphate (ATP). ATP is then used by our cells to facilitate a whole host of body functions from breathing to exercising.
Without delving too deep into cellular biology, mitochondria are essential to our energy metabolism, and because of this, they play a very important role in fatty acid oxidation (fat loss). For fat loss to occur, fatty acids must be mobilized from fat stores and sent to mitochondria to be oxidized so that they can be used for energy.
There can be thousands of mitochondria in each of our cells, and the human body has trillions of cells, so do the math – we have a lot of mitochondria. Still, it never hurts to have more.
In order to increase your mitochondrial density, you have to give your body a reason to produce more mitochondria. As with most components of the human body, if you don’t use it, you lose it. If your body doesn’t need them, it won’t produce them.
Our body is not going to undergo the highly energy intensive task to build and maintain new muscle tissue if it has no reason to. If it’s not going to be lifting heavy weights, it has no need to build muscle to lift it. And just like when you stop working out you lose muscle mass, when you stop providing a reason for mitochondria to be around, you lose them too – making fat loss much less efficient.
Both endurance and strength training cause an increased capacity for fatty acid oxidation that correlates with an increase in mitochondrial density. The higher demand for energy by muscles created a higher demand for mitochondria to provide it.
Within 24 hours of maximal intensity exercise, new mitochondria were being formed. The intensity of your exercise and the demand that places on your muscles is a major stimulator to increase mitochondrial density.
A combination of both endurance and resistance exercise causes a significantly higher degree of mitochondrial biogenesis than endurance exercise alone. Including both strength training and cardio into your fitness program is most effective for fat loss.
Branched-chain amino acid (BCAA) supplementation also increased mitochondrial biogenesis in skeletal muscle in studies .BCAAs are 3 of the 9 essential amino acids required for humans. These amino acids cannot be synthesized by the human body and must be supplied by your diet. Amino acids are the building blocks of protein, and is the reason why protein is an essential macronutrient. Eating between .8-1 gram of protein per pound of lean body weight should be enough to spur biogenesis.
Based on the scientific literature, if your goal is to boost your mitochondrial density and the corresponding degree of fatty acid oxidation (fat loss), focus your exercise program around resistance training and formulate a diet that is rich in protein, and low-glycemic carbohydrates.