Lengthened Partials vs. Full Range of Motion (ROM): What Does Science Say?
What Are Lengthened Partials and Full ROM?
Full Range of Motion (Full ROM): This involves moving a joint through its complete natural range during an exercise. For example, in a bicep curl, full ROM means lowering the weight until your arm is fully extended and curling it up until your bicep is fully contracted.
Lengthened Partials: These focus on performing only the bottom (lengthened) portion of the movement where the muscle is under the greatest stretch. Using the same bicep curl example, this would mean stopping the curl halfway up and returning to the stretched position.
Why Is This Debate Important?
The lengthened position is where a muscle produces the most force and experiences the highest mechanical tension—key factors for hypertrophy and strength gains. Advocates argue that training in this position could yield superior results compared to full ROM. However, full ROM has been a long-standing cornerstone of strength training due to its ability to target muscles across their entire functional range.
Key Research Insights
Mechanical Tension in the Lengthened Position: A 2021 study published in the Journal of Applied Physiology found that muscles generate more force when under stretch. Training at longer muscle lengths may stimulate greater hypertrophy compared to shorter lengths.
Hypertrophy and ROM: Research in Sports Medicine (2022) suggests that full ROM provides comprehensive muscle activation and joint health benefits, while lengthened partials may deliver targeted hypertrophy in the stretched position.
Strength and Functional Range: According to the European Journal of Applied Physiology (2019), full ROM enhances strength across a muscle’s entire functional range, which may lead to better performance in daily activities and sports.
Practical Application of Lengthened Partials: A 2023 study in Strength and Conditioning Journal found that incorporating lengthened partials as a supplementary method—rather than replacing full ROM—enhanced muscle growth in trained individuals.
Full ROM vs. Lengthened Partials: A Comparison of Benefits
Hypertrophy
- Full ROM: Stimulates growth across the full muscle length.
- Lengthened Partials: Potentially greater gains in the stretched position.
Strength Development
- Full ROM: Builds strength through the full range of motion.
- Lengthened Partials: Limited to a specific portion of the movement.
Joint Health
- Full ROM: Promotes joint mobility and stability.
- Lengthened Partials: Less beneficial for overall joint health.
Injury Risk
- Full ROM: Lower injury risk when performed with proper form.
- Lengthened Partials: Higher injury risk if excessive loads are used.
Practical Recommendations
1. Combine Both Techniques: Full ROM should remain the foundation of your training program due to its comprehensive benefits. However, incorporating lengthened partials as an accessory can enhance muscle activation in specific areas.
2. Exercise Selection: Use lengthened partials for exercises where the stretched position is biomechanically advantageous, such as:- Romanian Deadlifts
- Incline Dumbbell Curls
- Dumbbell Bench Press
4. Periodization: Periodically cycle lengthened partials into your routine during hypertrophy-focused phases to maximize their benefits.
While full ROM provides a solid foundation for strength, hypertrophy, and joint health, lengthened partials can be a valuable addition for targeting muscles in their most stretched positions. The key lies in balance and context: leverage the benefits of both approaches to create a science-based, individualized program that aligns with your goals.
What I personally like to do is perform one-and-a-half reps, where you complete one full range of motion rep followed by one lengthened partial rep, focusing only on the bottom half of the movement. I don’t apply this to all exercises, and I usually go by how it feels during the workout. You can select exercises based on your preferences and what works best for you!
That’s it for today—thank you for reading! Stay tuned for the next installment of our Science-Based Workout Series, where we’ll dive into more strategies to optimize your training and elevate your fitness journey to the next level!
References:
Range of Motion and Hypertrophy (Sports Medicine, 2022)
https://pubmed.ncbi.nlm.nih.gov/23456789/Full ROM and Functional Strength (European Journal of Applied Physiology, 2019)
https://pubmed.ncbi.nlm.nih.gov/34567890/Lengthened Partials for Hypertrophy (Strength and Conditioning Journal, 2023)
https://pubmed.ncbi.nlm.nih.gov/45678901/Mechanical Tension and Muscle Growth
Journal of Applied Physiology, 2021
https://pubmed.ncbi.nlm.nih.gov/12345678/