Full Range-of-Motion Resistance Training as a Flexibility Alternative
When you perform resistance training exercises through their complete range of motion (ROM), you're simultaneously stretching the muscles at their lengthened positions during each repetition, which can improve flexibility comparably to dedicated stretching sessions—potentially eliminating the need for separate stretching routines.
The Mechanism Behind This Effect
The American Heart Association guidelines explicitly recommend that resistance training should be performed "through a full range of motion" as a core prescription principle 1. When you execute exercises like squats, Romanian deadlifts, or overhead presses through their complete ROM, the target muscles are repeatedly taken to lengthened positions under load. This creates a stretching stimulus at the end ranges of each repetition.
Recent high-quality research directly supports this concept:
A 2024 randomized controlled trial found that full ROM resistance training produced identical flexibility improvements to static stretching in the sit-and-reach test (both groups showed large magnitude improvements, p < 0.01), while simultaneously delivering superior strength gains 2
The resistance training group in this study matched stretching volume precisely (4-8 sets of 8 repetitions × 4 seconds = same time under tension as 32-second stretches), demonstrating that the ROM improvements weren't simply due to greater training volume
The Evidence Base
Multiple studies confirm this dual benefit:
A 2011 study showed no difference between full-range resistance training and static stretching for improving hamstring flexibility, hip flexion, and hip extension ROM, though resistance training was superior for strength 3
A 2025 systematic review and meta-analysis found resistance training produced a moderate pooled effect size (g = 0.63) for improving joint flexibility, with high-intensity protocols showing even greater effects 4
Another 2025 study comparing 6 weeks of static stretching versus resistance training found both increased dorsiflexion ROM similarly (small to moderate effect sizes), though through slightly different mechanisms 5
Clinical Application
The practical implication is straightforward: If you're already performing resistance training exercises through full ROM 2-3 days per week (as recommended by AHA guidelines 1), you may not need additional stretching sessions unless you have sport-specific flexibility demands or specific joint restrictions.
Key Requirements for This to Work:
- Execute exercises through complete ROM: Don't cut movements short. A full squat, not a quarter squat; full overhead press, not partial range
- Control the eccentric (lowering) phase: The lengthening portion of each lift provides the stretching stimulus
- Train major muscle groups: Include exercises for chest, shoulders, back, hips, and legs as outlined in guidelines 1
- Maintain consistency: 2-3 sessions per week minimum
Important Caveats
This doesn't mean stretching is obsolete. The AHA guidelines still recommend flexibility training 2-3 days per week for all populations 1, 6. However, the evidence suggests that full ROM resistance training can satisfy much of this flexibility requirement, particularly for general fitness purposes.
When separate stretching remains important:
- Athletes in flexibility-dependent sports (gymnastics, dance, martial arts) still need sport-specific stretching 7
- Individuals with specific joint restrictions or movement limitations
- Cardiac patients and older adults (50-60+ years) who may benefit from the lower-intensity nature of stretching 1
- Those with musculoskeletal limitations where resistance training may pose injury risk 1
The Strength Advantage
A critical distinction: While both methods improve flexibility similarly, only resistance training simultaneously builds strength 2, 3. This makes full ROM resistance training more time-efficient for most people seeking both strength and flexibility adaptations. The 2024 study showed resistance training produced 2.44-3.36 times greater strength improvements than stretching while matching flexibility gains 2.
The mechanism for ROM improvement appears to be primarily increased stretch tolerance (your nervous system's willingness to allow greater joint motion) rather than actual changes in tissue stiffness, though resistance training may also reduce tendon stiffness more than stretching 5, 8.