There is plenty of evidence to link regular exercise with specific aspects of better health, such as measures of functionality in the brain and cardiovascular system. Here, however, researchers produce data to suggest that some of the protective effects of exercise decline in later old age. This may well be the case, but it is worth noting that this is a small study, and that other past studies have indicated that exercise at any age is beneficial:
Physical exercise in old age can improve brain perfusion as well as certain memory skills. This is the finding of [neuroscientists] who studied men and women aged between 60 and 77. In younger individuals regular training on a treadmill tended to improve cerebral blood flow and visual memory. However, trial participants who were older than 70 years of age tended to show no benefit of exercise. Thus, the study also indicates that the benefits of exercise may be limited by advancing age.
The 40 test volunteers were healthy for their age, sedentary when the study commenced and divided into two groups. About half of the study participants exercised regularly on a treadmill for 3 months. The other individuals merely performed muscle relaxation sessions. In 7 out of 9 members of the exercise group who were not more than 70 years old, the training improved physical fitness and also tended to increase perfusion in the hippocampus - an area of the brain which is important for memory function. The increased perfusion was accompanied by improved visual memory: at the end of the study, these individuals found it easier to memorize abstract images than at the beginning of the training program. These effects were largely absent in older volunteers who participated in the workout as well as in the members of the control group.
Physical exercise is known to have considerable health benefits: the effects on the body have been researched extensively, the effects on brain function less so. An increase in brain perfusion through physical exercise had previously only been demonstrated empirically in younger people. The new study shows that some ageing brains also retain this ability to adapt, even though it seems to decrease with advancing age. Furthermore, the results indicate that changes in memory performance resulting from physical exercise are closely linked to changes in brain perfusion.