Training muscles in a stretched position has gained traction in the fitness world, with research suggesting it can significantly enhance muscle growth.
A new study by Larsen et al. adds to this growing body of evidence, showing that working muscles in a lengthened position can lead to 43.3% greater hypertrophy compared to training in a shortened position.
For those looking to build muscle more efficiently, this research highlights a simple yet effective training tweak that may optimize results without requiring an entirely new workout routine.
Jump to:
- The Study: Investigating Lengthened Muscle Training
- The Results: More Growth in the Stretched Position
- How to Apply ‘Lengthened Supersets’ for More Muscle Growth
- Why This Matters for Strength and Hypertrophy
- Understanding Momentary Failure vs. Training Past Failure
- Why Training at Longer Muscle Lengths May Be Superior for Growth
- Practical Examples: Applying Lengthened Supersets to Other Exercises
- How to Program Lengthened Supersets in a Routine
The Study: Investigating Lengthened Muscle Training
The study, which is currently in pre-print, explored whether performing calf raises in a lengthened position (dorsiflexion) would lead to greater muscle growth than performing the same exercise in a shortened position (plantarflexion). Researchers focused on the medial gastrocnemius, a major calf muscle, to determine how training at different muscle lengths affected hypertrophy.
Study Methods: How It Was Conducted
Researchers recruited 23 untrained men and assigned each participant’s right and left leg to different training conditions.
- One leg performed Smith machine calf raises to failure in plantarflexion (toes pointed downward, heel raised).
- The other leg performed calf raises to failure in dorsiflexion (toes pulled upward, heel lowered for a deeper stretch).
- All participants trained for 12 weeks, progressively increasing volume:
- Muscle thickness was measured using ultrasonography before and after the study.
The Results: More Growth in the Stretched Position
The findings showed a significant difference between the two training methods. Participants who performed calf raises in the lengthened dorsiflexed position experienced 43.3% greater muscle growth in the medial gastrocnemius than those who trained in the shortened plantarflexed position.
These results reinforce the idea that training at longer muscle lengths—where the muscle experiences more stretch—may be superior for hypertrophy compared to working within a shortened range of motion.
How to Apply ‘Lengthened Supersets’ for More Muscle Growth
This study supports a growing trend in resistance training: long-length partial reps, also known as “lengthened supersets.” Fitness researcher Dr. Milo Wolf suggests incorporating this method to push past failure and stimulate more muscle growth.
How to Perform Lengthened Supersets
- Start with a standard set using a full range of motion (ROM) until failure or near failure.
- Without resting, perform another set focusing only on the bottom (lengthened) half of the movement until reaching the target level of effort.
For example:
- Calf Raises: Perform full ROM reps first, then follow up with partial reps in the stretched (bottom) position.
- Other Muscle Groups: This approach may be particularly effective for muscles undertrained in the lengthened position, such as the back, biceps, and rear delts.
Why This Matters for Strength and Hypertrophy
The findings suggest that strategically incorporating lengthened supersets into a workout routine could enhance muscle growth without requiring additional training volume. This method may be especially useful for bodybuilders and strength athletes looking to maximize hypertrophy efficiently.
As more research continues to explore stretch-mediated hypertrophy, lengthened supersets may become a key strategy for those aiming to optimize their training for greater muscle development.
Understanding Momentary Failure vs. Training Past Failure
To appreciate the significance of lengthened supersets, it’s important to differentiate between momentary failure and training past failure:
- Momentary Failure: The point at which a lifter can no longer complete a repetition with proper form. This is often considered the gold standard for maximizing hypertrophy.
- Training Past Failure: Extending the set beyond momentary failure by incorporating partial reps in the lengthened position. This ensures continued mechanical tension on the muscle, which is a key driver of muscle growth.
In this study, participants who trained beyond failure by including lengthened partial reps saw significantly greater gains in muscle thickness compared to those who stopped at momentary failure.
Why Training at Longer Muscle Lengths May Be Superior for Growth
Research increasingly supports the idea that training at longer muscle lengths stimulates greater hypertrophy than training at shorter lengths. Several mechanisms may explain this:
- Increased Mechanical Tension: The lengthened position allows muscles to generate more force, increasing tension at the sarcomere level—a key trigger for muscle growth.
- Enhanced Muscle Fiber Recruitment: Training past failure forces more high-threshold motor units (which contain type II muscle fibers) to activate, leading to greater adaptation.
- Improved Muscle Oxygenation and Metabolic Stress: Partial reps at long muscle lengths may enhance blood lactate accumulation and muscle deoxygenation, potentially promoting additional muscle growth.
These factors contribute to the 43.3% greater hypertrophy seen in the dorsiflexion group of the study.
Practical Examples: Applying Lengthened Supersets to Other Exercises
While this study focused on calf raises, lengthened supersets can be applied to multiple muscle groups that are typically undertrained in the stretched position. Here’s how:
Legs (Quadriceps & Hamstrings)
- Leg Extensions: Perform full-ROM reps until failure, then continue with bottom-half partials (where the quads are most stretched).
- Romanian Deadlifts: Stop at failure, then perform additional half-reps from the stretched bottom position to maximize tension on the hamstrings.
Back (Lats & Traps)
- Lat Pulldowns: Complete full-ROM reps until failure, then perform partials from the stretched overhead position to maintain lat engagement.
- Seated Rows: Perform full reps, then continue with partial reps in the stretched position where the shoulder blades are fully protracted.
Biceps & Triceps
- Dumbbell Curls: Perform full-ROM curls until failure, then follow up with partials at the bottom stretch position to maintain tension on the biceps.
- Overhead Triceps Extensions: Complete full reps, then do partial reps in the deep-stretch position to further fatigue the long head of the triceps.
By incorporating lengthened supersets into multiple muscle groups, lifters can maximize hypertrophy across the entire body.
How to Program Lengthened Supersets in a Routine
To effectively integrate lengthened supersets into training, consider the following guidelines:
- Exercise Selection: Choose movements that allow for a deep stretch at the bottom of the ROM (e.g., Romanian deadlifts, overhead extensions, leg presses).
- Set Structure:
- Perform full-ROM reps until reaching the target RPE (Rate of Perceived Exertion).
- Immediately continue with partials in the lengthened position until further fatigue is reached.
- Training Volume: Due to the increased intensity, keep lengthened supersets limited to 1-2 sets per exercise to avoid excessive fatigue.
- Rest & Recovery: Since lengthened training increases muscle damage, allow adequate recovery between sessions. Training the same muscle group with this method more than twice a week may lead to excessive soreness and hinder performance.
