Effects of Deloading Periods in Resistance Training on Muscular Strength and Hypertrophy

NCT06825052 | Completed

• 2 other identifiers: GAUN-SBF-PANCAR-02OFS
• Study Type: interventional
• Target: 19
• Locations: 1 country
• Sites: 1

Brief Summary

This study investigates the effects of deloading periods (short breaks or reductions in training volume) in a 8-week resistance training program on muscle strength and hypertrophy in young, untrained individuals. Participants were randomly assigned to two training conditions: Deload Training Group: Reduced training volume for one week every four weeks. Continuous Training Group: Regular training without reductions. Muscle thickness was measured using ultrasound, and muscle strength was evaluated through a 10-repetition maximum (10RM) test before and after the intervention. The findings showed that both training strategies led to significant increases in muscle strength and size, with no major differences between groups. This suggests that incorporating deloading periods does not negatively impact muscle development and may serve as an effective alternative for individuals with time constraints or minor injuries. This study was conducted at Gaziantep University, Faculty of Sports Sciences, with approval from the university's ethics committee.

Conditions

Muscle Hypertrophy in Healthy Young Men

Keywords

Muscle hypertrophy; muscle strength; resistance training

Outcome Measures

Primary Outcomes (1)

• Muscular Strength

  Changes in muscle strength will be assessed using 10-repetition maximum (10RM) testing before and after the intervention. Strength assessments will be conducted for both the quadriceps (leg extension) and biceps brachii (dumbbell curl).

  Baseline and after 8 weeks

Secondary Outcomes (1)

• Muscle Hypertrophy

  Baseline and after 8 weeks

Study Arms (2)

Deload Training

EXPERIMENTAL

Participants in this group followed an 8-week resistance training program with deloading periods every four weeks. During these deload weeks, training volume and intensity were reduced to facilitate recovery while maintaining training adaptations.

Behavioral: Resistance Training with Deloading Periods

Continuous Training

ACTIVE COMPARATOR

Participants in this group followed an 8-week continuous resistance training program with no reductions in training volume or intensity. This group served as a comparison to assess the effects of deloading periods on muscle hypertrophy and strength.

Behavioral: Continuous Resistance Training

Interventions

Resistance Training with Deloading Periods BEHAVIORAL

Participants performed an 8-week unilateral resistance training program in which training volume and intensity were reduced during weeks 4 and 8 to facilitate recovery and adaptation.

Deload Training

Continuous Resistance Training BEHAVIORAL

Participants followed an 8-week unilateral resistance training program without any deloading periods. Training volume and intensity remained consistent throughout the study.

Continuous Training

Eligibility Criteria

• Age: 18 Years - 25 Years
• Gender Eligibility Details: Only male participants were eligible to participate in the study. Gender identity was not a restriction, but biological sex was considered for eligibility.
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy, untrained individuals (no prior structured resistance training experience for at least 6 months).
• Aged between 18-25 years old.
• No current or recent musculoskeletal injuries affecting exercise performance.
• No diagnosed medical conditions that could interfere with resistance training.
• Willing to participate in an 8-week structured resistance training program.
• No use of performance-enhancing drugs, anabolic steroids, or other muscle-growth supplements.

You may not qualify if:

• Individuals with prior resistance training experience within the last 6 months.
• Any current or past musculoskeletal injuries or conditions affecting the lower or upper limbs.
• Any diagnosed metabolic, cardiovascular, or neurological disorders that could affect physical performance.
• Individuals currently taking medications that affect muscle function or recovery.
• Pregnant or breastfeeding individuals.
• Failure to comply with the study protocol (e.g., missing more than 2 training sessions).

Sponsors & Collaborators

• University of Gaziantep: lead

Study Sites (1)

Gaziantep University, Faculty of Sport Sciences

Gaziantep, Şehitkamil, 27350, Turkey (Türkiye)

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 Officials

• Zarife Pancar Assistant Professor,, PhD

  University of Gaziantep

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Masking Details: This study utilized a double-blind (participant and outcomes assessor) design to minimize bias in the evaluation of muscle hypertrophy and strength. Participants were unaware of which limb was assigned to the deload or continuous training condition to prevent psychological or behavioral influences on training performance. The outcomes assessor conducting muscle thickness measurements (using B-mode ultrasound) and strength assessments (10RM test) was blinded to the condition assignments to ensure unbiased data collection. The researchers responsible for training supervision were aware of the limb assignments but did not participate in the measurement or data analysis process. This blinding method was implemented to enhance the validity of the study and reduce potential bias in both subjective and objective outcome measures.
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: PhD, Assistant Professor,

Model Details: This study utilizes a crossover within-subject design, where each participant's limbs were assigned to two different training conditions: Deload Training Condition: Training volume and frequency were reduced for one week every four weeks. Continuous Training Condition: Training continued without volume reduction. Each participant performed unilateral leg extension and dumbbell biceps curl exercises twice per week for 8 weeks. One limb was assigned to the deload condition, while the other was assigned to the continuous training condition. This within-subject design was chosen to minimize inter-individual variability and enhance statistical power. Muscle hypertrophy and strength were assessed before and after the intervention using B-mode ultrasound and 10-repetition maximum (10RM) testing, respectively.

Study Record Dates

• First Submitted: February 4, 2025
• First Posted: February 13, 2025
• Study Start: May 1, 2024
• Primary Completion: June 25, 2024
• Study Completion: August 20, 2024
• Last Updated: February 13, 2025

Record last verified: 2025-02

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, CSR
• Time Frame: De-identified individual participant data (IPD), along with the study protocol and statistical analysis plan, will be made available upon request after study completion and publication. Researchers interested in accessing the data should contact the corresponding author. Data will be shared under a data-sharing agreement to ensure compliance with ethical and privacy guidelines.
• Access Criteria: De-identified individual participant data (IPD) and supporting documents, including the study protocol and statistical analysis plan, will be available upon reasonable request for research purposes. Access will be granted to qualified researchers affiliated with academic or research institutions. Researchers must submit a data-sharing request, including a brief study proposal outlining their intended use of the data. All data-sharing requests will be reviewed by the study team, and approved researchers must sign a data-sharing agreement to ensure compliance with ethical and privacy guidelines. Data will be shared in a secure format via institutional data-sharing platforms or encrypted file transfer.

Locations

TU (1)