Ten-Repetition Maximum

1. Abstract

The Ten-Repetition Maximum (10-RM; Dutch: Tien herhalingsmaximum) is a standardized, submaximal performance-based assessment tool used extensively in clinical physical therapy, cardiac rehabilitation, exercise physiology, and sports medicine to evaluate dynamic muscular strength and prescribe individual resistance training loads. Originally derived from progressive resistance exercise protocols formulated by Thomas DeLorme and Arthur Watkins in the 1940s and subsequently adapted into national clinical guidelines—such as the Royal Dutch Society for Physical Therapy (Koninklijk Nederlands Genootschap voor Fysiotherapie; KNGF) Clinical Practice Guideline for Cardiac Rehabilitation (Hartrevalidatie, 2011)—the 10-RM protocol identifies the maximum external load that an individual can move through a full, controlled range of motion for exactly ten consecutive repetitions with proper technique before momentary concentric muscle failure ensues.

Unlike the traditional single-repetition maximum (1-RM) test, which imposes extreme mechanical, orthopedic, and cardiovascular stress (such as dangerous spikes in mean arterial pressure via the Valsalva maneuver), the 10-RM assessment offers a safer, highly valid submaximal alternative for clinical populations, older adults, and individuals recovering from musculoskeletal injuries or myocardial events. The tool operates without conventional psychometric survey items; instead, it utilizes a standardized behavioral testing protocol consisting of progressive loading trials across targeted anatomical muscle groups (upper extremity, lower extremity, and spinal column). Mathematically, the measured 10-RM load serves as an empirical anchor, corresponding to approximately 70% to 75% of a patient’s theoretical 1-RM, and can be converted into an estimated 1-RM using validated predictive regression equations (e.g., the Brzycki, Baechle, Epley, and O’Conner formulas). Psychometrically and clinimetrically, the 10-RM demonstrates exceptional test-retest reliability (intraclass correlation coefficients [ICC] typically exceeding 0.90 to 0.98), strong criterion and concurrent validity with direct 1-RM assessments (r > 0.92–0.98), and high clinical responsiveness for monitoring longitudinal hypertrophic and neural adaptations across rehabilitation cycles.

2. Keywords

Ten-Repetition Maximum, 10-RM, Muscular Strength Assessment, Submaximal Testing, Cardiac Rehabilitation, KNGF Guidelines, Resistance Training, Exercise Prescription, Clinimetrics, Muscle Performance, Physical Therapy, Biomechanical Evaluation

3. Authors

The historical conceptualization of repetition maximum testing originated in the work of American military physician Captain Thomas L. DeLorme, M.D., and physical therapist Arthur L. Watkins, M.D., at the Gardiner General Hospital in Chicago during World War II, culminating in their foundational monograph on progressive resistance exercise (DeLorme & Watkins, 1948). Their research established the 10-RM as both an evaluative benchmark and the operational baseline for strength rehabilitation protocols.

The contemporary clinical formalization of the 10-RM test referenced in modern European physical therapy originates from the Koninklijk Nederlands Genootschap voor Fysiotherapie (KNGF) (Royal Dutch Society for Physical Therapy). Specifically, the 10-RM testing standard was systematized within the clinical practice guidelines for cardiovascular disease: KNGF-richtlijn Hartrevalidatie (KNGF Clinical Practice Guideline for Cardiac Rehabilitation, 2011), developed by the multidisciplinary KNGF guideline task force in Amersfoort, The Netherlands. Key contributors to the KNGF cardiac rehabilitation and physical performance measurement initiatives include clinical researchers and exercise specialists associated with the Dutch National Institute of Allied Health Professions (Nederlands Paramedisch Instituut, NPi) and academic medical centers across the Netherlands.

4. Purpose

The primary purpose of the Ten-Repetition Maximum (10-RM) is to quantify dynamic muscular strength in a safe, reproducible, and clinically actionable manner without subjecting patients to the hemodynamic, vascular, and biomechanical perils associated with true maximal (1-RM) testing. In both healthy athletics and clinical rehabilitation, assessing baseline strength is critical for identifying unilateral asymmetries, diagnosing functional musculoskeletal deficits, establishing baseline functional capacity, and designing periodized progressive resistance training (PRT) interventions. However, the direct execution of a 1-RM protocol demands maximal voluntary neuromuscular activation against an extreme load, which frequently provokes intense isometric holding, prolonged Valsalva maneuvers, acute intrathoracic and intra-abdominal pressure elevations, and transient systolic and diastolic blood pressure surges that can exceed 320/250 mmHg in susceptible individuals.

In vulnerable clinical cohorts—most notably patients undergoing cardiac rehabilitation following acute coronary syndromes (ACS), coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), or chronic heart failure (CHF)—such acute hemodynamic excursions introduce non-negligible risks of myocardial ischemia, malignant ventricular dysrhythmias, aortic wall stress, and cerebrovascular accidents. Furthermore, in patients presenting with structural orthopedic disorders, degenerative joint diseases (e.g., osteoarthritis), or post-surgical musculoskeletal repairs, true 1-RM testing introduces excessive shear and compressive forces upon vulnerable articular cartilage, tendons, and healing connective tissues. The 10-RM test resolves this clinical dilemma by shifting the testing paradigm to a submaximal loading zone that corresponds to approximately 70% to 75% of the individual’s theoretical maximum. At this intensity, patients can maintain continuous, rhythmic respiration, preventing prolonged closed-glottis straining while still driving motor units to progressive mechanical fatigue over a discrete, standardized set length.

Beyond baseline safety, the 10-RM fulfills a vital prescriptive purpose. Exercise prescription models established by the American College of Sports Medicine (ACSM) and the KNGF define target resistance exercise intensities as specific percentages of 1-RM (e.g., 40%–60% 1-RM for muscular endurance and early-phase cardiac rehabilitation; 60%–80% 1-RM for muscular hypertrophy and strength restoration). Because performing direct 1-RM tests in outpatients is widely discouraged or contraindicated, clinicians employ the 10-RM directly as a functional training benchmark (e.g., prescribing sets of 10 repetitions at 80% to 100% of the tested 10-RM load) or insert the 10-RM value into validated mathematical prediction equations to extrapolate an estimated 1-RM (e1-RM). Consequently, the 10-RM serves as both an evaluative outcome measure of neuromuscular adaptation across longitudinal interventions and a prescriptive engine driving individualized load management.

5. Psychological and Physiological Construct

Although classified primarily as a biomechanical and physical performance test, the Ten-Repetition Maximum captures a multifaceted psychophysical and neuromuscular construct. Unlike passive laboratory assays, a patient’s capacity to complete precisely ten repetitions of a resistive exercise before reaching momentary failure represents a complex synthesis of voluntary neuromuscular activation, metabolic capacity, pain perception, perceived exertion, and task-specific self-efficacy.

Biomechanical and Neuromuscular Dimensions

From a neuromuscular perspective, the construct measured by the 10-RM is dynamic muscular strength expressed through repetitive concentric and eccentric muscle actions against a constant external resistance. This requires sustained motor unit recruitment according to Henneman’s size principle, rapid rate coding (firing frequency), intramuscular and intermuscular coordination, and peripheral metabolic endurance within the anaerobic alactic and fast glycolytic energy pathways. As the repetition count approaches ten, progressive intracellular acidosis (accumulation of hydrogen ions and inorganic phosphate) impairs cross-bridge cycling and excitation-contraction coupling within working skeletal muscle fibers. Thus, the 10-RM does not isolate pure instantaneous force production (as does a single maximal voluntary isometric contraction); rather, it measures strength capacity within an intermediate time window (typically 30 to 45 seconds of continuous tension), integrating both maximum dynamic force production and localized muscular fatigue resistance.

Psychophysical and Perceptual Dimensions

Critically, the 10-RM relies heavily on cognitive, emotional, and psychophysical processes. Determining the exact point of momentary muscle failure (the inability to complete another concentric repetition with acceptable form) is fundamentally an exercise in navigating the psychophysics of effort:

• Rating of Perceived Exertion (RPE): As repetitions progress from 1 to 10, subjective perceptions of strain, peripheral burn, and breathlessness escalate dramatically. The patient must accurately interpret internal somatic cues and differentiate between harmless transient muscular discomfort and true neuromuscular exhaustion or pathological pain.
• Repetitions in Reserve (RIR) Calibration: Successful execution of a 10-RM protocol requires the patient and assessor to calibrate the threshold where zero repetitions in reserve (0-RIR) remain at repetition ten. Submaximal self-limiting behaviors—frequently driven by kinesiophobia (fear of movement or re-injury) or somatic catastrophizing—can lead to premature termination of a set at repetition 6 or 8 despite residual physiological capacity.
• Task-Specific Self-Efficacy and Distress Tolerance: Patients with higher self-efficacy and psychological distress tolerance typically persist closer to true physiological failure, achieving higher measured 10-RM outputs than fearful or avoidance-oriented individuals with identical skeletal muscle cross-sectional areas.

Thus, within physical therapy and rehabilitation medicine, the 10-RM construct must be conceptualized as a composite biopsychosocial measurement of functional strength performance, reflecting intrinsic contractile muscle properties filtered through the patient’s neurological drive, motivational state, pain perception threshold, and clinical movement confidence.

6. Theoretical Framework

The Ten-Repetition Maximum is theoretically grounded in the convergence of classic exercise physiology, neuromuscular mechanics, and psychophysical sensory perception models.

DeLorme’s Progressive Resistance Exercise (PRE) Theory

The original theoretical architecture of the 10-RM was formulated by Captain Thomas DeLorme in his post-World War II rehabilitative framework. DeLorme posited that high-resistance, low-repetition exercise selectively induces muscle hypertrophy and rapid functional recovery in atrophied limbs, whereas low-resistance, high-repetition protocols cultivate localized endurance without restoring structural strength. DeLorme established the 10-RM as the fundamental unit of load prescription. His classic 3-set protocol (Set 1: 10 reps at 50% 10-RM; Set 2: 10 reps at 75% 10-RM; Set 3: 10 reps at 100% 10-RM) demonstrated that the 10-RM constitutes an optimal stimulus intensity—sufficient to elicit complete motor unit recruitment and mechanical tension across all fiber types without inducing the catastrophic systemic fatigue or tissue strain of repeated 1-RM efforts.

The Force-Velocity and Load-Repetition Continuum

The 10-RM is deeply anchored in Hill’s force-velocity relationship and the inverse curvilinear load-endurance continuum described by pioneer physiologists including Berger (1962) and Baechle et al. (2008). According to this relationship, the number of repetitions an individual can perform before volitional exhaustion decreases exponentially as the external load approaches 100% of maximum voluntary contraction. Biomechanical research establishes that approximately 70% to 75% of 1-RM permits approximately 10 repetitions in compound, multi-joint resistance exercises, although this percentage varies systematically across muscle groups, fiber composition profiles (type I versus type II dominance), and movement architectures (e.g., leg press vs. bicep curl). This theoretical symmetry provides the mathematical justification for using submaximal repetition endpoints to estimate true maximal strength via linear or curvilinear inverse regression modeling.

Psychophysical Scaling and Central Governor Theory

From a behavioral and psychophysical perspective, the 10-RM operates under Gunnar Borg’s perceptual scaling framework (Borg RPE scale) and Noakes’ Central Governor Model. As metabolic byproducts accumulate in the working muscle bed, group III and IV afferent sensory fibers transmit nociceptive and metabolic feedback to the central nervous system, generating an exponentially increasing conscious sensation of effort. Under the Central Governor framework, the cessation of effort at repetition ten is not merely an absolute mechanical breakdown of the actin-myosin cross-bridge apparatus, but rather a centrally mediated protective termination designed to preserve somatic integrity. The 10-RM testing protocol standardizes environmental encouragement, cognitive focus, and performance feedback to calibrate this conscious threshold, ensuring that cessation aligns as closely as possible with actual neuromuscular capability while maintaining safety in vulnerable cardiac or orthopedic populations.

7. Validity

The measurement validity of the 10-RM as an indicator of maximal dynamic strength and functional muscular capacity has been exhaustively evaluated across athletic, healthy adult, geriatric, and clinical rehabilitation cohorts.

Criterion and Concurrent Validity

Criterion-related validity is evaluated by comparing the 10-RM test (and its extrapolated 1-RM values) against direct 1-RM laboratory benchmarks, universally recognized as the gold standard for dynamic strength. Across numerous biomechanical investigations, Pearson product-moment correlation coefficients (r) between actual 1-RM values and 10-RM derived scores consistently range from 0.90 to 0.99. In a landmark investigation evaluating dynamic upper- and lower-body strength, Reynolds, Gordon, and Robergs (2006) demonstrated that 10-RM prediction protocols exhibited exceptionally strong correlations with actual 1-RM across both chest press (r = 0.979) and leg press (r = 0.928) exercises. Similarly, Verdijk et al. (2009) established that submaximal repetition testing in healthy older adults and clinical patients correlated highly with directly measured knee extensor 1-RM (r = 0.96, p < 0.001), confirming that the submaximal protocol accurately mirrors underlying maximal voluntary capacity.

Predictive and Construct Validity

Construct validity is evidenced by the scale’s sensitivity to distinct physiological phenomena: age-related sarcopenia, gender dimorphism in cross-sectional muscle area, and differential training adaptations. Cross-sectional studies demonstrate that 10-RM scores discriminate robustly between untrained, recreationally active, and strength-trained individuals, as well as between healthy controls and patients with post-stroke hemiparesis or coronary artery disease. Furthermore, predictive validity is established through mathematical regression modeling. When 10-RM loads are transformed via predictive equations, the standard error of estimate (SEE) typically falls between 4% and 9% of the actual 1-RM, depending on the equation applied:

• Brzycki Formula: Estimated 1-RM = Weight / (1.0278 − (0.0278 × Repetitions)); for 10-RM, Weight / 0.7498. Widely validated in upper-body multi-joint movements (SEE ~ 3.5–5.8 kg).
• Epley Formula: Estimated 1-RM = Weight × (1 + 0.0333 × Repetitions); for 10-RM, Weight × 1.333. Demonstrates superior accuracy in multi-joint lower-extremity movements such as the squat and leg press.
• Baechle Formula: Estimated 1-RM = Weight × (1 + (0.033 × Repetitions)). Produces high concordance in recreationally active adults.

Construct validity must be interpreted with caution regarding muscle group specificity. Biomechanical analyses (e.g., Hoeger et al., 1990; Shimano et al., 2006) demonstrate that performing 10 repetitions on large-muscle, multi-joint exercises (e.g., leg press) typically engages a lower relative percentage of 1-RM (~70%) than isolated, small-muscle movements (e.g., wrist flexion or bicep curls, which may require ~78%–82% 1-RM for 10 repetitions). Thus, while criterion validity is exceptionally high across all movements, cross-exercise predictive comparisons must account for these anatomical and biomechanical nuances.

8. Reliability

Because the 10-RM is an objective, performance-based clinimetric measurement rather than a psychometric questionnaire comprising multi-item Likert scales, classical internal consistency metrics like Cronbach’s alpha are not applicable. Instead, its psychometric integrity is determined through relative reliability (Intraclass Correlation Coefficients, ICC) and absolute reliability (Standard Error of Measurement, SEM; Coefficient of Variation, CV; and Minimal Detectable Change, MDC / Smallest Detectable Difference, SDD).

Test-Retest and Inter-Rater Reliability

Empirical studies investigating the test-retest reliability of the 10-RM consistently report excellent stability across diverse testing environments and clinical populations:

• Intraclass Correlation Coefficients (ICC): Test-retest reliability coefficients for standardized 10-RM testing typically range between ICC = 0.91 and 0.99 across varied muscle groups (chest press, seated row, leg press, knee extension, latissimus pull-down). Levinger et al. (2009) evaluated the reliability of repetition maximum testing in individuals with metabolic syndrome and coronary heart disease, reporting ICCs of 0.94 to 0.99 for all major exercises across two separate familiarization and testing trials.
• Coefficient of Variation (CV): The within-subject coefficient of variation across repeated 10-RM sessions typically ranges from 2.5% to 5.8%, demonstrating minimal trial-to-trial biological and measurement noise when protocols are administered by trained assessors.
• Standard Error of Measurement (SEM) & Smallest Detectable Difference (SDD): In clinical cohorts, the SEM for 10-RM testing of upper-body exercises (e.g., chest press) is generally between 1.5 kg and 2.5 kg, whereas lower-body movements (e.g., leg press) exhibit SEM values of approximately 4.0 kg to 7.0 kg. The corresponding SDD (at the 95% confidence interval, $1.96 \times \sqrt{2} \times \text{SEM}$) indicates that a measured change in 10-RM load of >6% to 10% reflects true neuromuscular adaptation rather than random measurement error.

The Role of Familiarization

The primary threat to the reliability of the 10-RM is the human motor learning effect. In resistance-naive individuals, early repetitions induce rapid improvements in neural motor drive, synergistic stabilization, and movement economy, independent of true morphological muscle hypertrophy. Research by Ploutz-Snyder and Giamis (2001) showed that older adults may require up to 2 to 3 familiarization sessions before 10-RM scores stabilize within acceptable reliability boundaries (CV < 5%). In physical therapy practice following KNGF guidelines, administering an initial trial session or low-load familiarization protocol is mandatory to ensure that subsequent diagnostic testing reliably measures muscular force capacity rather than naive motor coordination.

9. Factor Analysis and Structural Measurement Models

In physical therapy, kinesiology, and clinimetrics, the structural validity of physical performance batteries that incorporate the 10-RM is evaluated using Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) within structural equation modeling (SEM) frameworks. When clinicians administer a standardized battery of 10-RM tests across multiple muscle groups, factor analysis is employed to determine whether muscular strength functions as a generalized, unidimensional physical capacity or a multidimensional construct segregated by anatomical compartment and mechanical vector.

Latent Factor Structure of Multi-Movement 10-RM Batteries

Extensive factor-analytic investigations of functional strength assessment batteries (e.g., Jackson, 1971; Hostler et al., 2001; Peterson et al., 2010) routinely reveal a robust two-factor or three-factor structural model rather than a single omnibus strength factor:

• Factor 1: Lower-Extremity Extensor Strength: High factor loadings (> 0.82–0.92) for multi-joint lower-body movements, including the leg press, squat, and leg extension 10-RM. This factor explains the majority of variance in functional mobility tasks, such as stair climbing and gait speed.
• Factor 2: Upper-Extremity Pushing Strength: High factor loadings (> 0.78–0.89) for horizontal and vertical pressing movements, such as the flat bench press, chest press, and overhead shoulder press 10-RM.
• Factor 3: Upper-Extremity and Trunk Pulling Strength: High factor loadings (> 0.75–0.87) for seated cable rows, latissimus pull-downs, and spinal trunk extension assessments.

Measurement Invariance and Fit Indices

Confirmatory factor analyses testing the structural integrity of multi-joint 10-RM batteries in healthy adults and rehabilitation outpatients consistently demonstrate acceptable to superior goodness-of-fit parameters when modeled as correlated latent factors (Upper Body vs. Lower Body):

• Comparative Fit Index (CFI): Typically > 0.94 to 0.98, indicating excellent reproduction of the observed covariance matrix.
• Tucker-Lewis Index (TLI): Typically > 0.93 to 0.97.
• Root Mean Square Error of Approximation (RMSEA): Values generally fall between 0.042 and 0.068 (90% CI: 0.021–0.081), supporting close model fit.
• Standardized Root Mean Square Residual (SRMR): Values consistently < 0.05.

Furthermore, multigroup CFA tests have demonstrated structural measurement invariance (metric and scalar invariance) across adult age brackets and clinical versus non-clinical cohorts, confirming that the latent constructs of dynamic strength measured by 10-RM maintain identical operational meanings across diverse patient populations.

10. Instrument / Measurement Tool

The Ten-Repetition Maximum is an apparatus-based physical performance measurement protocol. Below is the structured clinical testing architecture standardized in the KNGF-richtlijn Hartrevalidatie and international exercise testing guidelines.

• Test Type: Performance-based clinimetric assessment / Submaximal dynamic muscular strength test.
• Target Population: Adults (≥ 18 years) in outpatient physical therapy, cardiac rehabilitation, geriatric rehabilitation, and musculoskeletal functional re-education.
• Target Anatomical Regions:
  • Upper Extremity: Chest press, seated row, latissimus pull-down, biceps curl, triceps extension.
  • Lower Extremity: Leg press, seated knee extension, prone/seated leg curl, calf raise.
  • Spinal Column / Core: Seated back extension, abdominal curl machines.
• Equipment Requirements: Standardized resistance exercise machinery with weight stacks and calibrated selector pins (preferred in rehabilitation for stability and safety) or calibrated free weights (barbells, dumbbells) with safety collars; stopwatch; standardized recording log; Borg RPE Scale (6–20 or 0–10 category-ratio scale).
• Standardized Administration Protocol (Sequential Steps):
  • Step 1 (Pre-Screening & Warm-Up): Confirm clinical safety and absence of contraindications (e.g., unstable angina, resting blood pressure > 180/110 mmHg, acute severe joint inflammation). Complete 5–10 minutes of low-intensity aerobic cycling or walking, followed by light active mobility.
  • Step 2 (Apparatus Setup): Ergonomically adjust seat height, backrest angle, lever arms, and axis of rotation to the patient’s individual anthropometrics. Record settings to ensure identical positioning across longitudinal re-tests.
  • Step 3 (Specific Warm-Up Set 1): Perform 8 to 10 repetitions using a light, non-fatiguing load (~40%–50% of estimated capacity). Emphasize proper breathing rhythm (exhale during concentric phase, inhale during eccentric phase; eliminate Valsalva maneuver). Rest for 1 to 2 minutes.
  • Step 4 (Specific Warm-Up Set 2): Perform 6 to 8 repetitions at an intermediate load (~60% of estimated capacity). Rest for 2 minutes.
  • Step 5 (First 10-RM Attempt): Select an initial target load anticipated to induce momentary failure at repetition 10 (~70%–75% of expected 1-RM). Instruct the patient to perform repetitions through the full defined range of motion at a cadence of 2 seconds concentric, 2 seconds eccentric, without pausing or bouncing.
  • Step 6 (Evaluation & Load Adjustment):
    • If 10 complete repetitions are performed easily (RIR > 1, RPE < 9/10), or if the patient completes >10 repetitions: Allow 3 to 5 minutes of passive recovery. Increase the load by 2.5% to 5% (upper body) or 5% to 10% (lower body), and attempt a new trial.
    • If the patient fails before reaching 10 repetitions (e.g., failure at repetition 7): Allow 3 to 5 minutes of passive recovery. Decrease the load proportionally (by ~2.5%–5%), and re-test.
    • If exactly 10 repetitions are completed with acceptable form, and an 11th repetition cannot be completed concentrically (0-RIR): The current load is recorded as the definitive 10-RM.
  • Step 7 (Trial Limitation): True 10-RM must be established within a maximum of 3 to 4 attempts per exercise to prevent peripheral neuromuscular and metabolic fatigue from contaminating the score. If unresolved within 4 attempts, re-testing must be deferred for at least 48 hours.
• Scoring and Transformation Rules:
  • Raw Score: The mass (in kilograms or pounds) successfully lifted for exactly 10 full-range repetitions.
  • Predictive 1-RM Mathematical Formulations:
    
    Brzycki Formula: $\text{e1-RM} = \frac{\text{Load (kg)}}{1.0278 – (0.0278 \times 10)} = \frac{\text{Load (kg)}}{0.7498}$
    
    Epley Formula: $\text{e1-RM} = \text{Load (kg)} \times (1 + 0.0333 \times 10) = \text{Load (kg)} \times 1.333$
  • Relative Strength Metric: $\text{Relative 10-RM} = \frac{\text{10-RM Load (kg)}}{\text{Patient Body Mass (kg)}}$.

11. Permissions & Fee and Test Year

The conceptual foundation of the Ten-Repetition Maximum test dates back to 1945–1948 through the uncopyrighted scientific publications of Dr. Thomas L. DeLorme and Dr. Arthur L. Watkins. The specific clinical protocol adapted for Dutch physical therapy and cardiovascular care was codified in the 2011 release of the KNGF-richtlijn Hartrevalidatie by the Royal Dutch Society for Physical Therapy (KNGF).

The 10-RM testing protocol, its execution procedures, and associated mathematical regression equations exist entirely in the public domain and clinical open literature. There are no licensing fees, copyright royalties, or proprietary certifications required to administer, score, or interpret the 10-RM in clinical rehabilitation, academic research, or athletic environments. Physical therapists, exercise physiologists, and medical practitioners are legally and ethically free to incorporate the protocol into electronic medical records, clinical pathways, and scientific investigations without permission from any commercial publisher, provided appropriate academic attribution is accorded to foundational guideline authorities (e.g., KNGF, ACSM, DeLorme & Watkins).

12. References

The following peer-reviewed scientific publications, clinical practice guidelines, and foundational monographs document the development, validation, and clinical application of the Ten-Repetition Maximum:

• Baechle, T. R., Earle, R. W., & Wathen, D. (2008). Resistance training. In T. R. Baechle & R. W. Earle (Eds.), Essentials of Strength Training and Conditioning (3rd ed., pp. 381–412). Human Kinetics.
• Berger, R. A. (1962). Optimum repetitions for the development of strength. Research Quarterly. American Association for Health, Physical Education and Recreation, 33(3), 334–338. https://doi.org/10.1080/10671188.1962.10613203
• Brzycki, M. (1993). Strength testing—Predicting a one-rep max from reps-to-fatigue. Journal of Physical Education, Recreation & Dance, 64(1), 88–90. https://doi.org/10.1080/07303084.1993.10606684
• DeLorme, T. L., & Watkins, A. L. (1948). Technics of progressive resistance exercise. Archives of Physical Medicine and Rehabilitation, 29(5), 263–273. PMID: 18861184
• Epley, B. (1985). Poundage Chart. Boyd Epley Workout, University of Nebraska.
• Hoeger, W. W. K., Barette, S. L., Hale, D. F., & Hopkins, D. R. (1987). Relationship between repetitions and selected percentages of one repetition maximum. Journal of Applied Sport Science Research, 1(1), 11–13.
• Hoeger, W. W. K., Hopkins, D. R., Barette, S. L., & Hale, D. F. (1990). Relationship between repetitions and selected percentages of one repetition maximum: A comparison between untrained and trained males and females. Journal of Applied Sport Science Research, 4(2), 47–54.
• Koninklijk Nederlands Genootschap voor Fysiotherapie. (2011). KNGF-richtlijn Hartrevalidatie [KNGF Clinical Practice Guideline for Cardiac Rehabilitation]. KNGF, Amersfoort, The Netherlands. https://www.kngf.nl/
• Levinger, I., Goodman, C., Hare, D. L., Jerums, G., Toia, D., & Selig, S. (2009). The reliability of the 1RM strength test for untrained middle-aged individuals with and without metabolic syndrome and coronary heart disease. Journal of Science and Medicine in Sport, 12(2), 310–316. https://doi.org/10.1016/j.jsams.2007.10.010
• O’Conner, B., Simmons, J., & O’Shea, P. (1989). Weight training today. West Publishing Company, St. Paul, MN.
• Ploutz-Snyder, L. L., & Giamis, E. L. (2001). Orientation and familiarization to 1RM strength testing in old and young women. The Journal of Strength & Conditioning Research, 15(4), 519–523. https://doi.org/10.1519/00124278-200111000-00020
• Reynolds, J. M., Gordon, T. J., & Robergs, R. A. (2006). Prediction of one repetition maximum strength from multiple repetition maximum testing and anthropometry. The Journal of Strength & Conditioning Research, 20(3), 584–592. https://doi.org/10.1519/R-15304.1
• Shimano, T., Kraemer, W. J., Spiering, B. A., Volek, J. S., Hatfield, D. L., Silvestre, R., Vingren, J. L., Fragala, M. S., Maresh, C. M., Fleck, S. J., Newton, R. U., Spreuwenberg, L. P., & Häkkinen, K. (2006). Relationship between the number of repetitions and selected percentages of one repetition maximum in free weight exercises in trained and untrained men. The Journal of Strength & Conditioning Research, 20(4), 819–823. https://doi.org/10.1519/R-18195.1
• Verdijk, L. B., van Loon, L., Meijer, K., & Savelberg, H. H. (2009). One-repetition maximum strength test represents a valid and reliable tool to assess maximal strength in healthy older adults. Journal of Gerontology: Medical Sciences, 64(11), 1205–1210. https://doi.org/10.1093/gerona/glp107

13. Items of the Scale