Mitochondria are tiny bacteria, that billions of years ago invaded the cells of our ancient ancestor’s. They directly or indirectly, power everything that happens inside our cells. Their number per cell is a measure of cellular health.

Reduced levels underlie age-related muscle loss & debility, while higher-mitochondria-levels help ensure muscle:
1. Volume,
2. Health,
3. Ability to respond to therapy

The young (on average) respond to therapy faster. Given that mitochondrial number and activity declines with age, an ‘age related’ decline in people’s ability to respond to therapy seems self-evident, right? Wrong. It doesn’t need to be so.

A key for maintaining healthy muscle mitochondria with age is regular exercise. Terjung etal (2002), state that far from being a natural outcome of aging, reduced mitochondrial number & loss of muscle mass and function is more likely due to the fact that, as we get older, we become sedentary.

Research shows that:

Lifelong endurance training attenuates decline in both pumping efficiency and cardiac output of bloodExercise robustly increases building of new blood capillaries in muscle of older people

This increased ‘capillarity’ allows an increase in oxygen uptake of active muscle by 25%

Exercise sends hormonal signals to muscle. This results in significant increases in muscle cell mitochondrial content in older people. These new mitochondria are the end users of the oxygen for ATP production

Together the improvement in blood & oxygen delivery capacity combined with greater mitochondrial numbers, allows the production of significantly more ATP

This ensures great muscle power in every muscle cell during exercise

This mitochondrial capacity stays with us after exercise. So, during periods of rest in between bouts of training, muscles now have much-improved blood flow and nutrient and oxygen delivery, and greater energy production capacities, allowing highly efficient:a. repair of any tissue damage done during exercise,
b. building of new muscle cells & connective tissue
c. day to day function (including cell maintenance)
d. improved healing capacity

Again, it is easy to see why people who exercise heal more quickly. Exercise lowers inflammation both locally in muscle tissue and systemically. We will discuss this next month.