Alzheimer's disease (AD) is a progressive disease that destroys memory and other important mental activities. Scientists have found that remaining relatively active can lead to better brain activities in those at risk of developing AD. In some Meta-analyses of prospective investigations, a significantly reduced risk of dementia related to midlife exercise have been proven. Most studies have been performed on animal models about the effects of exercise on brain β-amyloid deposition, showed that the level of amyloid plaques are reducing significantly. In another study about the serum BDNF levels and exercise have recognized major transient increases of circulating BDNF with short-term aerobic exerciseThis information recommend that aerobic exercise is related to a decreased risk of cognitive impairment and dementia. A convergence of data from both human and animal studies proposes that aerobic exercise may reduce development of neurodegenerative processes and age-association loss of synapses. This may occur by a direct effect on neurodegenerative disease procedures or simplification of neuroprotective neurotrophic factors.