Objective In this study, it was aimed to examine the effect of 8-week exercise in Alzheimer's disease (AD) aged 65 and over through functional, cognitive, and biochemical parameters and irisin metabolism. Methods Two groups consisting of healthy individuals and diagnosed with Alzheimer's over the age of 65 were followed up with a combined exercise program of 45-60 min, 3 days a week, for 8 weeks. At the end of the exercise period, various cognitive and functional tests were performed on the participants, and blood samples were taken for biochemical parameters and irisin level measurements. Results In functional evaluations, while there was no difference in pre-exercise measurements of timed performance and quadriceps femoris muscle strength, there was a difference between groups in all other measurements (p < 0.05). Nutritional status increased significantly after exercise in AD individuals. Although there was an increase in mental score values after exercise, it was not statistically significant. Similar to the elderly with Alzheimer's, the improvements in functional tests in the healthy also led to improvements in activities of daily living and auxiliary activities of daily living. The exercise training did not have an effect on the lipid profile in AD patients, but showed an effect on glycemia and irisin levels (p < 0.05). Conclusion Changes in functional, cognitive, and biochemical parameters after the exercise program improved quality of life in Alzheimer's patients.