Why Exercise: Increase Your Mitochondria

I was attracted to a review in the ‘Nutrition Action' magazine about our mitochondria. There is now a lot being written in the anti-aging literature (and other literature) about these energy systems in our cells and how they relate to disease and aging.

In the review, mitochondria were described as the power plants of our cells. They convert food into energy, which the body uses to live. Most cells in the human body contain somewhere between 500 to 2,000 mitochondria and in fact, account for as much as 60 per cent of the volume of muscle cells and 40 percent of the volume of heart cells.

‘Mitochondria are linked to almost every essential process in cells'. This explains why you can trace almost any condition that has to do with energy balance-like diabetes or sarcopenia (which is muscle wasting with age), at least in part to problems with mitochondria.

As we age, mitochondria slow down in all our tissues. Also it's possible that weakened mitochondria leave people more susceptible to Parkinson's disease or accelerate the progression of Alzheimer's disease.

The good news is that aerobic exercise can increase the number of mitochondria in our muscle cells by 40 to 50 percent in six weeks, but you need a minimum of brisk exercise 20 minutes, four days a week. In 2006, research at the University of Pittsburgh's School of Medicine chose eight overweight and sedentary men and women in their late 60s to walk outdoors or use treadmills or stationary bicycles, four to six days a week, for 30 to 40 minutes each time. After 12 weeks, the mitochondria in their quadriceps (thigh muscles) increased by about 50 per cent.

Strength training will do the same, but it seems to be more effective in increasing mitochondria in older than younger people (it seems that aerobic activity is best for this process at younger ages.)

Mitochondria may also help explain why people who exercise regularly have a lower risk of type 2 diabetes and insulin resistance. Insulin resistance develops when fat builds up in the cells. The most common cause of fat build-up is consuming more calories than we burn. If we build up too much fat, there is more insulin resistance. Worse yet, as we age, our mitochondria are less able to get rid of fat.

In a study in 2007, it was found that middle-aged obese diabetics who cut their calorie intake by 25 percent and who did moderate-intensity exercise on most days for four months, boosted their mitochondria by 67 per cent and their insulin sensitivity by 59 per cent.

In a nutshell, this is all to say that there is very good reason why we all should exercise. Beyond the known cardiac, hypertension and psychological benefits, consistent exercise increases the mitochondria, which also reduces the risk of other weight-related conditions.