The overarching objective is to examine the brain-based biological mechanistic pathway by which exercise exerts anxiolytic effects. The investigators will measure brain-derived markers of mitochondrial metabolism (acetyl-L-carnitine [LAC]) and inflammation (interleukin-6 [IL-6]) using innovative technology to isolate neuronal exosomes.

Inclusion Criteria:

For both participant groups: To be eligible to participate in this study, an individual must meet all of the following criteria:

• Between 18-50 years of age
• Currently sedentary (≤60 minutes of moderate intensity exercise per week for the past 3 months)
• Capable and willing to provide informed consent

For anxiety disorder participant group, an individual must also meet:

• Primary psychiatric diagnosis of generalized anxiety disorder (GAD), social anxiety disorder, or panic disorder

Exclusion Criteria:

• Lifetime history of Bipolar I or II or any psychotic disorder
• Bulimia or anorexia in the past 3 months
• Alcohol or substance use disorder in the past 3 months
• Current major depressive disorder (past is allowed)
• Current neurologic disorder
• High current suicide risk (active suicidal ideation with plan and intent) as indicated by a score of ≥4 on the Columbia Suicide Severity Rating Scale (C-SSRS) consistent with a need for referral to higher level of care
• Participation in concurrent evidence-based therapy (e.g., cognitive behavioral therapy) targeting anxiety and/or depression (supportive therapy and couples therapy are allowed)
• Risk for exercise according to the Physical Activity Readiness Questionnaire with excluded active medical conditions including heart conditions, lung disease, bone/joint problems, or seizures
• Women who are currently pregnant or plan to become pregnant during the duration of the study
• current psychiatric medication
• Current substance abuse or positive urine toxicology screen (recreational use of marijuana is permitted based on clinical assessment on the MINI structured diagnostic interview that it does not meet criteria for cannabis use disorder)
• Active infection

Non-psychiatric controls who meet the following criteria will be excluded from participation in this study:

• Current psychiatric condition assessed by the MINI

Deidentified data will be made available if requested.