Body composition changes with obesity medications, with or without exercise

Inclusion Criteria:

* Both males and females of all race/ethnic groups are eligible for participation in this study.
* 18 to \<65 years of age.
* Newly prescribed FDA-approved obesity manage medication that can include Tirzepatide, Semaglutide, or up to 4 additional next-generation obesity management medications (will receive DSMB approval prior to inclusion), approval for treatment (pharmacy, insurance, etc.), and the participant agreeing to start this treatment and continue treatment for at least 6 months (the participant will be recruited prior to this medication being initiated).
* Body mass index (BMI) of \>=27.0 kg/m2 with at least one weight-related complication (hypertension, dyslipidemia, obstructive sleep apnea, or cardiovascular disease) provided it does not compromise the ability to safely complete the screening or outcome measures or to engage in the prescribed exercise interventions), or \>=30 kg/m2 without weight-related complications. We will not limit enrollment based on an upper BMI level provided that the participant meets the other eligibility requirements. However, the participant will be excluded if they exceed the weight or size limits of the dual-energy x-ray absorptiometry (DXA) system that is used to assess body composition or the MRI that is used to assess muscle quality.
* Ability to provide informed consent prior to participation in this study.
* Clearance from the study physician for meeting all eligibility criteria for this study.

Exclusion Criteria:

* Type 2 diabetes.
* Report moderate-to-vigorous exercise for \>60 min/week, and \>1 day/week of structured cardiovascular or resistance exercise over the past 3 months.
* Report sustained weight loss of \>=3% in the past 3 months.
* History of metabolic/bariatric surgery.
* Females who are pregnant or breastfeeding or reporting a planned pregnancy during the study period.
* Report a current medical condition or treatment for a medical condition that could affect body weight or contradict engagement in any aspect of the outcome measures or interventions.
* History of muscle conditions that may impact the quality of muscle or response to the study interventions (e.g., myopathy, muscular dystrophy, rhabdomyolysis, etc.).
* Contraindications to MRI (e.g., metal implants that are not MRI safe, etc.). NOTE: Participants who are otherwise eligible other than being contraindicated for the MRI scan will be eligible and the MRI scan will not be performed as a research procedure.
* Current congestive heart failure, angina, uncontrolled arrhythmia, symptoms indicative of an increased acute risk for a cardiovascular event, prior myocardial infarction or history of cardiomyopathy, coronary artery bypass grafting or angioplasty, conditions requiring chronic anticoagulation (i.e., recent or recurrent DVT).
* Resting systolic blood pressure of \>=160 mmHg or resting diastolic blood pressure of \>=100 mmHg. If medicated for blood pressure control, the medication dose needs to be stable for \>=6 months.
* Eating disorders that would contraindicate weight loss or physical activity.
* Alcohol or substance abuse.
* Current psychological condition that is untreated, hospitalization for a psychological condition within the past 12 months, or not being on a stable dose of treatment for at least 6 months.
* Report plans to relocate to a location not accessible to the study site or having employment, personal, or travel commitments that prohibit attendance at scheduled intervention sessions or assessments.