The Effects of Strength Training on Muscle Mass and Mental Health in Adults Taking Obesity Medication (STRONG)

The Effects of Strength Training on Muscle Mass and Mental Health in Adults Taking Obesity Medication: A Pilot Study

The purpose of this study is to examine the effects of resistance exercise, such as weightlifting, on retention of muscle mass and mental health in individuals taking GLP-1 RAs (an obesity medication). Resistance exercise is focused on increasing the strength of participants' muscles, such as how much participant can lift.

•The duration of this study is 3 months. This includes:

• Orientation session to explain study protocol, exercise program, and complete questionnaire about participants' medical history and lifestyle.
• Two health assessments at baseline and at 3 months. These assessments include body composition, resting blood pressure, cardiovascular function, and muscular strength. Both the resistance exercise group and the control group will complete assessments at baseline and again at 3 months. After the 3-month period, individuals in the control group may choose to participate in the exercise training and complete the optional 6-month assessments.
• Personalized resistance exercise sessions for 60 minutes per session, twice per week, for 3 months.

Study Overview

• Status: Recruiting
• Conditions: Obesity; Muscle Composition; Quality of Life (QOL)
• Intervention / Treatment: Behavioral: Resistance Exercise; Drug: GLP-1 RAs

Detailed Description

• After the baseline assessment, if participants meet all eligibility criteria such as BMI, blood pressure, physical activity levels, and medication conditions, investigators will randomly assign participants to control group or resistance exercise group:

1. Control group: No resistance training during the first 3 months. After the 3-month period, participants may choose to participate in the optional exercise program, which includes 60 min/session, all for 2 sessions/week for 3 months. Participants may follow their provider's guidance for exercise except not to perform any strength or resistance training.

2. Resistance exercise group: 60 min/session, all for 2 sessions/week for 3 months.

   • Resistance exercise group (60 min/session): Each session will be 60 minutes of resistance, performing 3 sets of 8-20 repetitions (50-80% 1RM) of 11 exercises (chest press, lat pulldown, abdominal crunch, leg press, shoulder press, weighted row, leg extension, leg curl, chest fly, biceps curl, and triceps extension) using weight training machines.

Investigator will also ask participants to maintain their usual (pre-study) lifestyle physical activity outside of exercise sessions and to monitor participants' daily activity throughout the study period using pedometers and a lifestyle activity log.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jiyeon Yoon, M.S.; Phone Number: 512-817-4601; Email: jiy239@pitt.edu

Study Locations

• United States
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15219
      • Recruiting
      • Physical Activity Research Center, University of Pittsburgh
      • Contact: Jiyeon Yoon, M.S.; Phone Number: 5158174601; Email: jiy239@pitt.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Initiating GLP-1 RAs prescribed by physician or advanced practice practitioner and willing to withhold the start of the drug until baseline assessment completed
• Non-Smoker
• ≥18 years old
• Obese: Body Mass Index 30-45 kg/m² or BMI ≥27 + ≥1 weight related comorbidity; either hypertension or sleep apnea confirmed by participant self-report
• Inactive: not meeting the current US exercise guidelines over the past 6 months
• Capable of performing the required exercise training

Exclusion Criteria:

• A serious heart condition, such as unstable heart disease or heart failure, irregular heartbeats that are not well controlled, severe narrowing of the heart valves, or any recent inflammation of the heart or its lining
• Cancer requiring treatment in the past 5 years
• Hypothyroidism/hyperthyroidism
• Personal or family history of Medullary Thyroid Carcinoma (MTC) or Multiple Endocrine Neoplasia Syndrome type 2 (MEN2)
• Gastroparesis
• Chronic/idiopathic acute pancreatitis
• Hepatic disease or cirrhosis
• Struggle with alcohol or other substance abuse (heavy drinking (≥4 drinks/day or ≥8 drinks/week for women; ≥5 drinks/day or ≥15 drinks/week for men), or who score ≥3 on the Drug Abuse Screening Test (DAST-10))
• Diabetes (Type 1 or 2)
• Major risk factors for coronary heart disease such as uncontrolled high blood pressure (≥160 mm Hg systolic or ≥100 mm Hg diastolic)
• Problems with your muscles or bones that limit your ability to exercise
• Any other medical condition that is life-threatening, can interfere with or be aggravated by the exercise training
• Plans to be away ≥2 weeks in the next 3 months
• Participation in any other concurrent interventional clinical trial
• History of eating disorders or weight-loss surgery, unstable weight (±5% change in past 6 months), or use of obesity medication (e.g., such as Wegovy, Ozempic, Saxenda, Zepbound, Mounjaro) in the last 3 months
• Inability to give informed consent
• History of major depression or other severe psychiatric disorders (e.g., who answer "yes" to question 9 on PHQ-9 in the Psych_QoL_Sleep questionnaires.)
• Pregnant or plan to become pregnant during study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Resistance Exercise (RE); Participants will perform 60 min of resistance exercise 2 sessions per week for 12 weeks while continuing GLP-1 RAs therapy as prescribed by regular treating provider	Behavioral: Resistance Exercise; 60 min/session, all for 2 sessions/week for 12 weeks; Drug: GLP-1 RAs; Participants will take GLP-1 RAs for 12 weeks
Active Comparator: Standard Care; Participants will take GLP-1 RAs for 12 weeks as prescribed by regular treating provider	Drug: GLP-1 RAs; Participants will take GLP-1 RAs for 12 weeks

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Body Composition	Dual-energy X-ray absorptiometry (DEXA) will be used to assess fat mass and lean mass. Body fat will be expressed as a percentage of total body composition, and lean mass will be expressed as a percentage of total body composition. Change in each variable will be calculated as the Week 12 value minus the baseline value. Positive values indicate an increase in body fat or lean mass, and negative values indicate a decrease.	From Baseline to Week 12
Change in Quality of Life	Quality of life will be assessed using the 36-Item Short Form Health Survey (SF-36). Scores range from 0 to 100, with higher scores indicating better quality of life. Change will be calculated as Week 12 minus baseline.	From Baseline to Week 12

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Muscle Strength	Grip strength will be measured three times in each hand using a Jamar dynamometer, and one-repetition maximum (1RM) will be measured using leg press and chest press machines.	From Baseline to Week 12
Energy Intake	Energy intake will be assessed using the Automated Self-Administered 24-hour (ASA24) dietary assessment tool.	From Baseline to Week 12
Physical Activity and Sleep	Participants will be asked to wear a GENEActiv tri-axial wrist-worn accelerometer for a 7-day period to quantify physical activity and sedentary behavior. Participants will be instructed to wear the device continuously for 24 hours per day throughout the 7-day measurement period.	From Baseline to Week 12

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cardiovascular Fitness	Cardiovascular fitness will be assessed using a submaximal treadmill test with the Balke-Ware protocol.	From Baseline to Week 12

Collaborators and Investigators

• Sponsor: University of Pittsburgh
• Collaborators: University of Pittsburgh Medical Center
• Investigators: Principal Investigator: Jiyeon Yoon, M.S., University of Pittsburgh

Publications and helpful links

Helpful Links

• Benefits of Exercise
• Exercise and Physical Fitness
• Exercise for Older Adults
• GLP-1 RAs
• Obesity
• Weight Control

Study record dates

Study Major Dates

• Study Start (Actual): May 25, 2026
• Primary Completion (Estimated): April 30, 2027
• Study Completion (Estimated): May 31, 2027

Study Registration Dates

• First Submitted: January 11, 2026
• First Submitted That Met QC Criteria: June 10, 2026
• First Posted (Actual): June 17, 2026

Study Record Updates

• Last Update Posted (Actual): June 17, 2026
• Last Update Submitted That Met QC Criteria: June 10, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Therapeutics; Physical Therapy Modalities; Patient Care; Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Physical Conditioning, Human; Exercise; Resistance Training
• Other Study ID Numbers: STUDY25090068

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Datasets will be available to outside researchers and public health professionals through the web sites of ClinicalTrials.gov and The Physical Activity Research Center (PARC) at the University of Pittsburgh. Outside researchers can learn what data are available and request a de-identified dataset (stripped of all personal health identifiers). All data requests will be discussed with the research team and approval will be obtained from the institutional review board overseeing the proposal of the data analysis project. Findings from the proposed study will also be published in peer-reviewed journals. The investigators seek to maximize the knowledge generated from this study by sharing data to expedite the translation of research into practice, with the goal of preserving lean body mass and improving quality of life.
• IPD Sharing Supporting Information Type: ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No