Is Deliberate Stretching Still Necessary for Flexibility?
Brandon Hyatt, MS, CSCS
Dec. 04, 2024
For decades, dedicated stretching sessions have been prescribed to enhance flexibility. But in today’s fitness landscape, does deliberate stretching—beyond strength and hypertrophy training—still hold value?
Traditional Fitness Frameworks vs. Modern Evidence
Traditional fitness models—including those from the American Council on Exercise (ACE) and American College of Sports Medicine (ACSM)—classify flexibility training as a core component of comprehensive exercise, alongside muscular strength, endurance, and cardiorespiratory fitness. Historically, this meant prioritizing stretching (both static and dynamic) as the primary method to boost flexibility and overall fitness.
Yet with the multitude of critical fitness domains to address, allocating time to stretching can extend the already demanding process of improving fitness. This article examines whether additional stretching is necessary for individuals already engaged in strength training.
What Do Recent Studies Reveal?
Emerging research indicates that resistance training delivers flexibility and range of motion (ROM) benefits equivalent to standalone stretching (3, 6, 7). For instance, resistance training has been termed “dynamic loaded stretching” (10), as it inherently incorporates stretch-like movements through full ROM contractions.
This aligns with practical experience: exercises like the Romanian deadlift or cable chest fly take joints through complete eccentric (lengthening) and concentric (shortening) phases with each repetition. Moreover, muscle stretching is a known driver of hypertrophy via the mechanism of stretch-mediated hypertrophy (10)—where stretch itself contributes to muscle growth.
Crucially, the reverse is not true: stretching does not meaningfully enhance muscle strength or hypertrophy (9). One study found that seven hours of weekly calf stretching produced identical strength and hypertrophy outcomes to just 45 minutes of weekly resistance training (9).
Why Resistance Training Matches Stretching for Flexibility
Resistance training with a full ROM generates both passive (tissue stretch) and active (muscle contraction) tension—key drivers of flexibility gains. Specifically:
Connective tissues are stretched beyond their resting length and subjected to elevated torque (7).
Resistance training increases muscle fascicle length (the basic structural unit of muscle fibers) in both eccentric and concentric muscle groups (4).
The mechanisms underlying stretching’s effects on flexibility—structural (e.g., longer fascicles), mechanical (e.g., reduced muscle stiffness), and sensorial/neural (e.g., improved stretch tolerance)—are also activated by resistance training (1).
Both acute and chronic stretching have limited efficacy for long-term ROM gains. Similar improvements can be achieved through interventions that acutely raise body temperature (e.g., light cardio), while chronic mechanical tension applied to lengthened muscles—the primary driver of lasting flexibility—is readily achievable via resistance training (Warneke et al., 2024).
Stretching in Warm-Ups vs. Cool-Downs
Warm-Ups
Stretching during warm-ups is commonly believed to acutely improve ROM, proprioception, and psychological readiness—yet none of these benefits are unique to stretching. Static stretching can prolong warm-ups and reduce strength, power, and speed (3)—effects that can be mitigated by following static stretches with dynamic movements (e.g., leg swings).
Cool-Downs
Cool-down stretching is often promoted for recovery, but studies comparing it to rest or low-intensity cycling found no differences in outcomes: all three methods aided recovery equally (2).
Injury Prevention
Injury risk is multifactorial, and no single factor (including stretching) can be isolated as a primary cause. The link between flexibility and injury risk is either uncorrelated or poorly understood (5, 8). A stronger predictor of injury is recovery status: as the body’s ability to recover declines, injury risk rises.
So, Is Stretching Worth Your Time?
For individuals already lifting weights and training through the fullest ROM possible, deliberate stretching is likely unnecessary for flexibility gains. Research confirms that each resistance training repetition provides sufficient muscle stretch to drive gradual flexibility improvements over time.
If you lift weights but still experience tightness, modify exercises or select variations that emphasize the eccentric (lengthening) phase—e.g., slowing the descent of a squat or prioritizing the stretch position in a chest fly. This targets tight muscles without adding separate stretching sessions.
Conclusion
The current evidence suggests that stretching is not a mandatory component of fitness for those engaged in regular strength training. Resistance training—when performed through a full ROM—delivers equivalent (or superior) flexibility benefits while also building strength and muscle. For most people, the time spent on separate stretching sessions could be better allocated to compound lifts or recovery.
References
Afonso J, Andrade R, Rocha-Rodrigues S, et al. What We Do Not Know About Stretching in Healthy Athletes: A Scoping Review with Evidence Gap Map from 300 Trials. Sports Med. 2024 Jun;54(6):1517–1551.
Afonso J, Clemente FM, Nakamura FY, et al. The Effectiveness of Post-exercise Stretching in Short-Term and Delayed Recovery of Strength, Range of Motion and Delayed Onset Muscle Soreness: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Front Physiol. 2021 May 5;12:677581.
Afonso J, Olivares-Jabalera J, Andrade R. Time to Move From Mandatory Stretching? We Need to Differentiate "Can I?" From "Do I Have To?". Front Physiol. 2021 Jul 22;12:714166.
Afonso J, Ramirez-Campillo R, Moscão J, et al. Strength Training versus Stretching for Improving Range of Motion: A Systematic Review and Meta-Analysis. Healthcare (Basel). 2021 Apr 7;9(4):427.
Behm DG, Alizadeh S, Daneshjoo A, Konrad A. Potential Effects of Dynamic Stretching on Injury Incidence of Athletes: A Narrative Review of Risk Factors. Sports Med. 2023 Jul;53(7):1359–1373.
Nuzzo JL. The Case for Retiring Flexibility as a Major Component of Physical Fitness. Sports Med. 2020 May;50(5):853–870.
Rosenfeldt M, Stien N, Behm DG, et al. Comparison of resistance training vs static stretching on flexibility and maximal strength in healthy physically active adults, a randomized controlled trial. BMC Sports Sci Med Rehabil. 2024;16:142.
Small K, Mc Naughton L, Matthews M. A systematic review into the efficacy of static stretching as part of a warm-up for the prevention of exercise-related injury. Res Sports Med. 2008;16(3):213–231.
Warneke K, Behm DG, Alizadeh S, et al. Discussing Conflicting Explanatory Approaches in Flexibility Training Under Consideration of Physiology: A Narrative Review. Sports Med. 2024 Jul;54(7):1785–1799.
Warneke K, Lohmann LH, Lima CD, et al. Physiology of Stretch-Mediated Hypertrophy and Strength Increases: A Narrative Review. Sports Med. 2023 Nov;53(11):2055–2075.
