up. The sex of the participants is not important to this study.MeasuresThe Beck Depression Inventory (BDI) (Beack, Steer, &Garbin, 1988) will be used to measure depression throughout the experiment. The BDI measures several concepts related to the model of human occupation. These include social withdrawal, work difficulty, sense of failure, self-dislike and indecisiveness.Heart Rate monitors will be used to measure the heart rates of the participants. DesignThis experiment will use a randomized, controlled design. The pre-test and post-test scores will be compared between the three groups in the experiment. The participants of the study will be randomly assigned to one of the three groups: the combination of aerobic and anaerobic exercise, aerobic exercise, and anaerobic exercise. Once again, there will be no control group in this experiment as it has been show, in several studies, that aerobic exercise has a positive effect on depression, therefore, a control group would be of no use to help support any findings. The participants will not be told the reason for this experiment. They will, however, be told that mood and fitness levels were being measured in order to reduce expectancy bias. This is one of the reason why measures of heart rate are used in this experiment. Operational DefinitionsThe independent variable is the type of exercise performed in this study. Aerobic exercise is defines as aerobics, for 45 minutes, two to four times per week, and anaerobic exercise is defined as weight lifting two or two to four times per week, depending on the condition. The dependent variable is depression. This is defined by the diagnostic and Statistical Manual of Mental Disorders Third Edition Revised (America Psychiatric Association, 1987) as dysphoric and/or irritable mood or loss of interest and pleasure accompanied by four of the following: significant weight change, sleep disturbance, psychomotor agitation or retardation, energy loss, fe...
