Hip Thrust Versus Back Squat Training in Untrained Adults

NCT07760220 | Completed

• 1 other identifier: protocol #: 22-588
• Study Type: interventional
• Target: 39
• Locations: 1 country
• Sites: 1

Brief Summary

This study compared the effects of two lower-body resistance training exercises - the barbell back squat and the barbell hip thrust - on muscle growth and strength in untrained young adults. Thirty-four participants were randomly assigned to train using either the back squat or the hip thrust, two times per week for nine weeks. Muscle size (via MRI) and strength (via weightlifting tests) were measured before and after training to determine whether one exercise produced greater improvements than the other, particularly in the gluteal muscles. Muscle activity during the first training session was also measured using surface electromyography (sEMG) to see whether early muscle activation could predict later muscle growth.

Conditions

Muscle Hypertrophy; Muscle Strength

Outcome Measures

Primary Outcomes (1)

• Hypertrophy

  Cross-sectional area of the upper, middle, and lower gluteus maximus was measured via magnetic resonance imaging (MRI) at baseline and following the 9-week training intervention. T1-weighted transverse images were obtained using a 3T MRI scanner, and muscle borders were manually traced using ImageJ software by a single investigator blinded to group allocation. Bilateral (left + right) mCSA values were summed at each of three standardized anatomical sites (upper, middle, and lower gluteus maximus) to assess site-specific hypertrophic response to training.

  Baseline and 9 weeks

Secondary Outcomes (2)

• 3RM strength testing

  Baseline and 9 weeks

• One-bout EMG gluteal maximus recordings

  Single training session within the first week of the intervention.

Study Arms (2)

Hip thrust (HT)

EXPERIMENTAL

Participants performed barbell hip thrust training only for 2 sessions per week for 9 weeks.

Behavioral: Resistance training

Back Squat (SQ)

ACTIVE COMPARATOR

Participants performed barbell back squat training only for 2 sessions per week for 9 weeks.

Behavioral: Resistance training

Interventions

Resistance training BEHAVIORAL

Participants performed training twice per week (non-consecutive days) for 9 weeks, totaling 15-17 supervised sessions. Training volume progressed weekly: 3 sets in week 1, 4 sets in week 2, 5 sets in weeks 3-6, and 6 sets in weeks 7-9, matching the set-volume scheme used in the hip thrust group. Each set consisted of 8-12 repetitions performed to volitional muscular failure (defined as the inability to complete another repetition with proper form); load was adjusted as needed to keep repetitions within this range. Repetitions were performed with a controlled tempo (\~1-second concentric, \~2-second eccentric). All training sessions were supervised by study personnel. Participants were instructed to refrain from any other lower-body resistance training for the duration of the study.

Back Squat (SQ); Hip thrust (HT)

Eligibility Criteria

• Age: 18 Years - 30 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age 18-30 years
• Body mass index (BMI) less than 30 kg/m²
• Minimal resistance training experience, defined as averaging ≤1 day per week of resistance training over the preceding 5 years
• Willing and able to provide written informed consent.

You may not qualify if:

• Participation in structured endurance training (e.g., running or cycling) more than 2 days per week over the past 6 months
• Known overt cardiovascular or metabolic disease
• Use of supplemental creatine and/or hormone-altering agents (e.g., testosterone boosters, growth hormone boosters) within the past 2 months
• Any medical condition that would contraindicate participation in an exercise program
• Any condition precluding MRI scanning (e.g., medically implanted devices)

Sponsors & Collaborators

• Auburn University: lead

Study Sites (1)

School of Kinesiology

Auburn, Alabama, 36849-5419, United States

Location

MeSH Terms

Interventions

Resistance Training

Intervention Hierarchy (Ancestors)

Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Patient Care; Therapeutics; Physical Therapy Modalities; Physical Conditioning, Human; Exercise; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Participants were not blinded to group allocation, as blinding was not feasible given the distinct nature of the two training exercises (back squat vs. barbell hip thrust). Investigators supervising training sessions were also not blinded, as they administered the assigned exercise protocol. During strength testing (3-repetition maximum and isometric wall push assessments), investigators were not blinded to group allocation due to logistical constraints, and the authors note that potential bias in this context cannot be fully ruled out. However, investigators were blinded to group allocation during MRI data collection and analysis; muscle cross-sectional area measurements were performed by a single investigator who did not have knowledge of participants' training group assignments.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: August 7, 2026
• First Posted: August 12, 2026
• Study Start: January 20, 2023
• Primary Completion: April 29, 2023
• Study Completion: January 17, 2024
• Last Updated: August 12, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ICF

Locations

US (1)