Table 1.

Eligibility Criteria Based on PICOS.

PICOS	Inclusion Criteria	Exclusion Criteria
1. Population	1.1. Adults (age, 18–65 years) diagnosed with major depression or unipolar depression according to the criteria of a validated instrument, such as the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), or the International Classification of Diseases 10th Revision (ICD-10), without restrictions based on sex or fitness level.	1.1. Children, adolescents, or older adults. 1.2. Presence of another primary neurological or psychiatric diagnosis, such as dementia, bipolar disorder, or psychosis. 1.3. Medical comorbidities that limit participation in physical exercise activities (e.g., significant musculoskeletal difficulties). 1.4. Active drug or alcohol abuse or dependence. 1.5. Pregnant or lactating women. 1.6. Intellectual disability.
2. Intervention	2.1. Chronic exercise intervention programs (with a minimum duration of 3 weeks) as independent therapy or complementary to usual psychiatric treatment (e.g., pharmacological treatment). 2.2. The interventions should involve aerobic training or strength training or programs combining different types of exercises (e.g., coordination, endurance, or strength training).	2.1. Acute interventions. 2.2. Chronic exercise intervention programs combined with meditation. 2.3. Chronic interventions that are not related to physical exercise.
3. Comparator	3.1. A group made up of adults diagnosed with depression not exposed to physical exercise intervention. 3.2. The control condition may be active (e.g., relaxation techniques) or passive (e.g., placebo).	3.1. Absence of control group.
4. Outcome	4.1. Pre–post-intervention values for one or more direct assessment measures for the executive functions of working memory, inhibition, or cognitive flexibility.	4.1. Indirect measures of executive functions (e.g., questionnaire).
5. Study design	5.1. Longitudinal studies with at least one experimental group and one control group that include pre- and post-intervention measurements.	5.1. Cross-sectional studies.