Muscle Hypertrophy in Healthy Young Men
Conditions
Keywords
Muscle hypertrophy, muscle strength, resistance training
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.
Detailed description
This study examines the effects of deloading periods (planned reductions in training volume and frequency) within an 8-week resistance training program on muscle hypertrophy and strength in untrained young individuals. The study utilized a randomized within-subject design, where each participant's limbs were assigned to one of two conditions: Deload Training Condition: Training volume and frequency were reduced during Weeks 4 and 8 to allow for recovery. Continuous Training Condition: No reductions in training volume were applied. The resistance training program included unilateral leg extension and unilateral dumbbell biceps curl exercises performed twice per week. The training intensity was adjusted to ensure participants reached voluntary muscular failure within the 8-12 repetition range. Assessments & Measurements: Muscle Hypertrophy: Measured using B-mode ultrasound at different quadriceps and biceps locations. Muscle Strength: Evaluated through 10-repetition maximum (10RM) testing before and after the intervention. Statistical Analysis: A 2-way repeated-measures ANOVA was used to compare training conditions, with effect sizes analyzed to determine the significance of adaptations. The study was approved by the Gaziantep University Health and Sports Sciences Ethics Committee and conducted in accordance with the Declaration of Helsinki guidelines.
Interventions
BEHAVIORALResistance Training with Deloading Periods
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.
BEHAVIORALContinuous Resistance Training
Participants followed an 8-week unilateral resistance training program without any deloading periods. Training volume and intensity remained consistent throughout the study.
Sponsors
University of Gaziantep
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
DOUBLE (Subject, Outcomes Assessor)
Masking description
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.
Intervention model description
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.
Eligibility
Sex/Gender
MALE
Age
18 Years to 25 Years
Healthy volunteers
Yes
Inclusion criteria
* 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.
Exclusion criteria
* 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).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Muscular Strength | Baseline and after 8 weeks | 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). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Muscle Hypertrophy | Baseline and after 8 weeks | Changes in muscle thickness will be measured using B-mode ultrasound imaging. Measurements will be taken at multiple anatomical points on the quadriceps and biceps brachii muscles before and after the intervention. |
Countries
Turkey (Türkiye)
Outcome results
None listed