Study: Best type of exercise

As reported in the NYT ... a study by the Mayo Clinic, published in Cell Metabolism journal this month evaluates the affect that certain types of exercise have on cellular health of muscles, the ability of mitochondria to produce energy for muscle cells, the gains in muscle mitochondrial function, and muscular maintenance and hypertrophy.

"The toll that aging takes on a body extends all the way down to the cellular level. But the damage accrued by cells in older muscles is especially severe, because they do not regenerate easily and they become weaker as their mitochondria, which produce energy, diminish in vigor and number. A study ... suggests that certain sorts of workouts may undo some of what the years can do to our mitochondria" . -- NYT

Study subjects, including a group over 64, was measured on aerobic fitness, their blood-sugar levels, and the gene activity and mitochondrial health in their muscle cells. The study group was divided into 4 groups:

• 1) no exercise 
• 2) vigorous weight training several times per week 
• 3) high intensity interval training three times per week 
• 4) moderate biking for 30 min few times a week, light weights

Results found in the biopsied muscle cells among the older subjects indicate a change in genes believed to influence the ability of mitochondria to produce energy for muscle cells.

The subjects who did the high intensity interval workouts showed the most increases in the number and health of their mitochondria, almost 400 genes were working differently now, compared with 33 for the weight lifters and only 19 for the moderate exercisers.

It seems as if the decline in the cellular health of muscles associated with aging was “corrected” with exercise, especially if it was intense, says Dr. Sreekumaran Nair, a professor of medicine and an endocrinologist at the Mayo Clinic and the study’s senior author. In fact, older people’s cells responded in some ways more robustly to intense exercise than the cells of the young did — suggesting, he says, that it is never too late to benefit from exercise. -- NYT 

Here again, more evidence to suggest the benefits of high intensity interval training (HIIT),  especially for older people.  HIIT reverses aging on the cellular level.