Discussion
The purpose of the present study was to determine the effect of an
aerobic exercise and vitamin D supplements on the quality of sleep and
neurocognitive functions of elderly women. The main finding was that the
three neurocognitive factors in the experimental groups were better than
the control group and the ATDG showed the better improvements compared
to ATG and VDG. That is, both factors of nutrition and physical activity
have had a double effect on the neurocognitive status of elderly women.
The obtained results are consisitent with a previous study that pointed
out that therapeutic supplementation can fascilitate the response time
and information processing (18). Contrary to the results of the present
study, Antypa et al. (2009) showed that the use of supplements in the
main foods had no significant effect on the change in performance and
the tasks that require decision making (19)(7). Differences in age
groups (elderly versus youth), supplementation modes, and different
research designs are of reasons in obtaining the divergent results. As
indicated, the neurocognitive performance of elderly people improved
significantly after aerobic exercises. For information processing, it
was shown that the experimental groups were in a better condition than
the control group. On the other hand, the selective attention of
experimental groups were also better compared to control group. It
should be noted that selective attention plays an important role in
motor control of the elderly (20). In this regard, the results of the
present study concerned the effectiveness of exercises on psychomotor
function is consisitent with the results of the research of Monleon et
al. (2018) who reported that appropriate exercise protocols lead to
optimal psychomotor functions. Along with the current study, some
studies have suggested that any type of exercise program that has
decision-making challenges can lead to improved neurocognitive behavior
in the elderly (18, 20). An explanation of these findings might be that
changes and adaptations of the musculoskeletal system caused by
functional exercises improve neurocognitive function. Possible reasons
for this result include the use of more effective neural units,
reorganization in the sensory cortex, increased efficacy of synaptic
connections and activation of the nervous system, and reducing neural
inhibitory reflexes (21). It has to be acknowledged that vitamin D
deficiency is cross-sectionally associated with neurocognitive
disfunctions, particularly mental shifting, information processing, and
processing speed (8, 9). Furthermore, when results have been combined
across trials, meta-analytic studies have consistently reported
cognitive benefits from aerobic exercise interventions (10, 11).
There are some limitations in the present study. This research may have
been underpowered due to a relatively smaller sample size. It is also
possible to study both sexes together. To study each sex separately
would remove sex as a confounding factor. Further studies that include
subjects in both acute and chronic effects of vitamin D and exercise
protocols are needed.
In conclusion, aerobic exercises plus vitamin D supplements improve the
neurocognitive functioning of elderly women. As this condition improves
as a result of increasing the quality of life of the elderly, it is
recommended that vitamin D supplementation and aerobic exercise be used
in conjunction with older women.