Does Performing Partial Repetitions Beyond Momentary Failure Enhance Muscle Hypertrophy in Volume-Load-Equated...

Area of Science:

• Exercise Physiology
• Muscle Physiology
• Sports Science

Background:

• Muscular hypertrophy is influenced by training volume and range of motion (ROM).
• Extending sets with partial ROM repetitions may enhance training stimulus.
• The efficiency of partial ROM repetitions added to full ROM sets for hypertrophy is not well-established.

Purpose of the Study:

• To investigate if extending traditional calf-raise resistance training sets with partial-range-of-motion (ROM) repetitions enhances muscular hypertrophy.
• To compare the effects of full ROM (MF) versus partial ROM added to full ROM (PBF) training on gastrocnemius muscle thickness.

Main Methods:

• Sixteen untrained men underwent 10 weeks of unilateral calf-raise training.
• One leg performed traditional full ROM sets to momentary failure (MF).
• The other leg performed full ROM sets to failure followed by partial ROM repetitions to a second failure (PBF).
• Total volume-load was equated between conditions.
• Muscle hypertrophy was assessed via ultrasound imaging of gastrocnemius muscle thickness.

Main Results:

• Both MF and PBF elicited equivalent changes in averaged muscle thickness (8% increase for both).
• Partial ROM added to full ROM failure (PBF) demonstrated greater per-set efficiency (0.16%) compared to full ROM failure (MF) (0.08%).
• PBF allowed for greater volume-load accumulation per set.

Conclusions:

• Extending full ROM sets with partial ROM repetitions to failure (PBF) may increase training volume load per set.
• Under volume-load-equated conditions, PBF and MF result in similar gastrocnemius muscle hypertrophy in untrained young men after 10 weeks.
• Partial ROM repetitions can be an efficient method to enhance muscle hypertrophy stimulus on a per-set basis.