Fragmentation in the intermyofibrillar mitochondria and a reduction in the cristae was found to be responsible for nearly all of the changes in the well-known metric of VO2max. Unsurprisingly, the density of the subsarcolemmal mitochondria was found to be associated with the muscles’ ability to extract oxygen from blood.
The researchers believe that their findings explain the basic reasons why people lose strength with age, even in the absence of defined sarcopenia. They also warn that this mitochondrial dysfunction only gets worse with aging. Furthermore, they hold that their findings “reflect an early ageing phenotype, making the mitochondrial changes observed herein strong candidates for intervention studies aiming to slow the progression of the effects of ageing on physical function.”
As exercise is associated with mitochondrial fusion [8] and one study had suggested that six months of endurance training can compensate for 30 years of aging [9], the authors suggest that further research on exercise in older people should be done with a close examination into mitochondrial changes.
