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Cited by 81Sports Performance and TrainingCardiovascular and exercise physiologyMuscle Physiology and Disorders

What makes long-term resistance-trained individuals so strong? A comparison of skeletal muscle morphology, architecture, and joint mechanics

Open access
Maden-Wilkinson, Thomas M., Balshaw, Thomas G., Massey, Garry J., Folland, Jonathan P.·2020·Journal of Applied Physiology
DOI 10.1152/japplphysiol.00224.2019PMC PMC7191505
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Abstract

Here we demonstrate that the larger muscle strength (+60%) of a long-term (4+ yr) resistance-trained group compared with untrained controls was due to their similarly larger muscle volume (+56%), primarily due to a larger physiological cross-sectional area and modest differences in fascicle length, as well as modest differences in maximum voluntary specific tension and patella tendon moment arm. In addition, the present study refutes the possibility of regional hypertrophy, despite large differences in muscle volume.

AI snapshot

Written from the paper’s full text.

TL;DR

In a cross-sectional comparison, long-term resistance-trained men had ~60% greater knee extensor strength than untrained men, primarily explained by their ~56% greater quadriceps muscle volume rather than by specific tension or moment arm. The larger muscle volume was mainly due to greater physiological cross-sectional area (+41%), with a smaller fascicle length contribution (+11%), and there was no evidence of regional hypertrophy.

Key findings

  • LTT had substantially greater maximal voluntary torque (+60%; 388 ± 70 vs. 245 ± 43 N·m, P < 0.001, ES = 2.5) and quadriceps volume (+56%; 2,881.9 ± 308.1 vs. 1,838.2 ± 262.9 cm³, P < 0.001, ES = 3.7).
  • Muscle size indices were much larger than specific tension or moment arm differences: QACSAMAX +50%, QPCSA +41%, QEFFPCSA +41%, ST +8% (36.1 ± 5.3 vs. 33.3 ± 4.5 N·cm², P = 0.04), and PTMA +4% (4.33 ± 0.24 vs. 4.17 ± 0.28 cm, P = 0.03); PTMA normalized to height did not differ (P = 0.92).
  • The greater QVOL was primarily attributable to QPCSA (+41%, sarcomeres in parallel) rather than QFL (+11%, sarcomeres in series); QΘP was +13% in LTT.
  • No evidence of regional hypertrophy was found between or along the constituent quadriceps muscles: proportional muscle volumes, ACSAMAX locations, and relative ACSA along the femur did not differ between groups (adjusted P > 0.21). In whole-cohort regression, QVOL was the only determinant of MVT (R² = 0.81, P < 0.001).

Methods

  • Cross-sectional study of 68 young men: LTT (n = 16, age 21.6 ± 2.0 yr) with 4.0 ± 0.8 yr of systematic knee extensor heavy-resistance training, and UT (n = 52, age 25.1 ± 2.3 yr) with no lower-body resistance training for >18 mo.
  • Knee extension dynamometry with hamstring EMG for antagonist coactivation; MRI for quadriceps volume, ACSAMAX, and patella tendon moment arm; B-mode ultrasound at 10 quadriceps sites for pennation angle and fascicle length; PCSA, effective PCSA, and specific tension were calculated.
  • Analyses included independent t-tests, 4 × 2 ANOVA for constituent muscles, Benjamini–Hochberg correction, Pearson correlations, and stepwise multiple regression; duplicate strength sessions were averaged for 66 of 68 participants.

Limitations

  • The paper states that the cross-sectional design and retrospective training history limited information about exact training loads, contraction types, and periodization; a repeated-measures design before/during/after prolonged training would be stronger.
  • The paper states that imaging was performed at rest and at a different knee joint angle than strength testing, and that B-mode ultrasound is a 2-D representation of a 3-D structure, with fascicle extrapolation typically ≤10% of measured fascicle length.
  • Evident from the text: the sample was restricted to young men, the LTT group was relatively small (n = 16), and training was not experimentally supervised, so causality and generalizability to women, older adults, or supervised training contexts are not established.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1152/japplphysiol.00224.2019

Cites

79 of 79 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 42 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    LTT men had 41% greater quadriceps effective physiological cross-sectional area (QEFFPCSA) than UT men.

    “QEFFPCSA 41% greater in LTT compared with UT (P < 0.001, ES = 4.1)”
    • Also stated in: § RESULTS · plain
      “QEFFPCSA (cm2) | 167.7 ± 18.8 | 236.8 ± 15.1* | 41 | 4.1”
    Quote in the paperSubstantial claim
  • Findingown data

    LTT men had greater quadriceps maximum voluntary specific tension (ST) than UT men, by about 8-9%, when accounting for antagonist coactivation, corrected patella tendon moment arm, and QEFFPCSA.

    “smaller differences in ST (+9%, P < 0.05)”
    • Also stated in: § RESULTS · plain
      “There was 8% greater ST of the quadriceps in LTT than UT (33.3 ± 4.5 N·cm2 vs 36.1 ± 5.3 N·cm2; P = 0.04, ES = 0.6; Fig. 4A) when accounting for antagonist coactivation, corrected PTMA, and QEFFPCSA.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: There is a linear relationship between EMG amplitude and torque.
  • Findingown data

    LTT men had 50% greater quadriceps maximal anatomical cross-sectional area (QACSAMAX) than UT men.

    “QACSAMAX was 50% greater (P < 0.001, ES = 3.3)”
    • Also stated in: § RESULTS · plain
      “QACSAMAX (cm2) | 86.2 ± 11.2 | 135.0 ± 15.0* | 50 | 3.3”
    Quote in the paperSubstantial claim
  • Findingown data

    LTT men had 56% greater quadriceps muscle volume (QVOL) than UT men.

    “QVOL (+56%, P < 0.001)”
    • Also stated in: § RESULTS · plain
      “QVOL was 56% greater in LTT than UT (P < 0.001; ES = 3.7)”
    Quote in the paperSubstantial claim
  • Findingown data

    LTT men had 4% greater patella tendon moment arm (PTMA) than UT men.

    “moment arm (+4%, P < 0.05)”
    • Also stated in: § RESULTS · plain
      “LTT had a 4% greater PTMA than UT (4.17 ± 0.28 cm vs. 4.33 ± 0.24 cm; P = 0.03; ES = 0.6: see Fig. 4B).”
    Quote in the paperNot a substantial claim
  • May combine two claims. 14
  • Classified as probably not a substantial claim. 22

  • May combine two claims.

    Findingown data

    The proportional size of individual quadriceps muscles and distribution of muscle mass along the femur were no more variable for LTT than UT groups.

    “inspection of the variability (between participant standard deviation) indicates that the proportional size of the individual quadriceps’ muscles (Table 1) and distribution of muscle mass along the femur (Fig. 3) were no more variable for LTT than UT groups.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    LTT individuals had greater skeletal muscle quantity and higher maximal voluntary specific tension (ST) than UT individuals.

    “the greater muscle strength of LTT (+60%) was accompanied by both a greater quantity of skeletal muscle and higher ST.”
    • Also stated in: § DISCUSSION · plain
      “The greater MVT of LTT was accompanied by both a greater quantity of skeletal muscle and higher specific tension”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The present study found a clear difference for 3 of 4 individual muscles (VM, VL, RF), a tendency for a difference in the fourth (VI), and over the whole muscle group QFL showed a highly significant difference with a large effect size (+11%, P < 0.01, ES 1.2).

    “we found a clear difference for 3 of 4 of the individual muscles (VM, VL, and RF), a tendency for a difference in the fourth (VI), and over the whole muscle group QFL showed a highly significant difference with a large effect size (+11%, P < 0.01 ES 1.2).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    Longer fascicles due to addition of sarcomeres in parallel appear to result in a disproportionately larger increase of sarcomeres in parallel and could be a key explanation for the differences in muscle size (ACSA, PCSA, and volume) observed.

    “In essence, longer (extended) fascicles due to the addition of sarcomeres in parallel appears to result in a disproportionately larger increase of sarcomeres in parallel and therefore could be a key explanation for the differences in muscle size (ACSA, PCSA, and volume) we have observed.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    A greater QΘP is thought to be beneficial for isometric force production up to an optimum angle of 45°.

    “Overall a greater QΘP is thought to be beneficial for isometric force production up to an optimum angle of 45° (8).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [8] Alexander R, 1975, J Hum Mov Stud

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    The acquisition of clear T1 MR images along the whole thigh (~25 min) is not compatible with measurements during contraction.

    “The acquisition of clear T1 MR images along the whole thigh (~25 min) is not compatible with measurements during contraction”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The greater strength of LTT men compared with UT men was due to their larger muscle volume, primarily due to larger physiological cross-sectional area and modest differences in fascicle length, as well as modest differences in maximum voluntary specific tension and patella tendon moment arm.

    “Here we demonstrate that the larger muscle strength (+60%) of a long-term (4+ yr) resistance-trained group compared with untrained controls was due to their similarly larger muscle volume (+56%), primarily due to a larger physiological cross-sectional area and modest differences in fascicle length, as well as modest differences in maximum voluntary specific tension and patella tendon moment arm.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: There is a linear relationship between EMG amplitude and torque.

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    Due to constraints of the MRI scanner bore, muscle size and moment arm measurements were taken at a different knee joint angle to the strength measurements.

    “due to the constraints of the bore within the MRI scanner, muscle size and moment arm measurements were also taken at a different knee joint angle to the strength measurements.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The greater muscle size of LTT men in combination with a more modest difference in QΘP resulted in a difference in QEFFPCSA, which alongside smaller contributions from ST and moment arm appears to explain the strength difference.

    “This greater muscle size of LTT in combination with a more modest difference in QΘP (+12%) resulted in a difference in QEFFPCSA (+40%), which alongside other smaller contributions from ST (+8%) and moment arm (+4%) appears to explain the strength difference.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: There is a linear relationship between EMG amplitude and torque.

  • May combine two claims.

    Interpretationown data

    The greater QVOL of LTT individuals was due primarily to enhanced QPCSA, indicating more sarcomeres in parallel.

    “the greater QVOL (+56%) of LTT was due primarily to enhanced QPCSA (41%), indicating more sarcomeres in parallel”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    These discrepancies could potentially confound the comparison of strength and morphological variables.

    “These discrepancies could potentially confound the comparison of strength and morphological variables.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    LTT individuals have a stiffer patella tendon compared with UT individuals.

    “Although we have recently found LTT to have a stiffer patella tendon compared with UT”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [56] source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    Participants were excluded if involved in activities that might compromise morphological adaptations to resistance training.

    “we excluded participants involved in activities (e.g., weight category and endurance sports) that might compromise morphological adaptations to RT.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductreasoning

    Duplicate strength measurement sessions were separated by 7-10 days and typically averaged to enhance the reliability of criterion measurements.

    “The duplicate strength measurement sessions were typically averaged (for 66 of 68 participants) to enhance the reliability of criterion measurements.”
    • Also stated in: § MATERIALS AND METHODS · plain
      “followed by two duplicate strength measurement sessions separated by 7–10 days.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Premisenone given

    PCSA is theoretically the best index of contractile material (sarcomeres and cross-bridges) arranged in parallel.

    “Theoretically PCSA is the best index of contractile material (sarcomeres and cross-bridges) arranged in parallel.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductcitation

    P values were corrected for multiple tests using the Benjamini-Hochberg procedure with a false detection rate of 5%, and significance was defined as adjusted P < 0.05.

    “P values were corrected for multiple tests using the Benjamini–Hochberg procedure (13) with a false detection rate of 5%, and significance was defined as adjusted P < 0.05.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [13] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S4 (based).

    Premisenone given

    Force transmission to the tendon is increasingly compromised according to the cosine of ΘP.

    “although force transmission to the tendon is increasingly compromised (according to the cosine of ΘP).”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    EFFPCSA, calculated by multiplying PCSA by the cosine of mean pennation angle, is the theoretically best index of muscular force/torque production.

    “To correct for force transmission to the tendon, EFFPCSA was calculated as this theoretically best index of muscular force/torque production.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [28] source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    Quadriceps femoris CSAs and architecture are known to change substantially between rest and maximum contraction.

    “For example, quadriceps femoris CSAs and architecture are known to change substantially between rest and maximum contraction (55).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [55] source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductown data

    Use of a relatively long probe (92 mm vs. commonly used 40-60 mm) minimized the need for extrapolation of fascicle trajectory beyond the recorded image (typically <10% of the measured FL was extrapolated).

    “by using a relatively long probe (92 mm vs. commonly used 40–60 mm) we were able to minimize the need for extrapolation of fascicle trajectory beyond the recorded image (typically <10% of the measured FL was extrapolated).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    The greater strength of LTT appears to produce similar muscle shortening, and thus presumably architectural changes, at maximal voluntary contraction.

    “the greater strength of this group appears to produce similar muscle shortening, and thus presumably architectural changes, at MVC (56).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [56] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    It is conceivable that diverse individual hypertrophic responses cumulatively canceled out and led to no overall regional hypertrophy.

    “it is conceivable that this may have resulted in diverse individual hypertrophic responses that cumulatively canceled out and led to no overall regional hypertrophy.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: The LTT individuals in the current study had been doing a range of different training practices.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    This contrast may indicate an anatomical specificity to muscle architectural changes after resistance training or site-specific differences.

    “This contrast may indicate an anatomical specificity to muscle architectural changes after RT or site-specific differences.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationcitation

    Increased specific tension could be attributable to changes in neuromuscular activation or an increase in intrinsic contractile specific tension, perhaps due to a shift in muscle fiber phenotype or alterations in muscle architecture.

    “Increased specific tension could be attributable to changes in neuromuscular activation [e.g., increased agonist activation (10, 60)] or an increase in the intrinsic contractile specific tension, perhaps due to a shift in muscle fiber phenotype (20) or alterations in muscle architecture (24).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [10] source

      Not checked in the free run.

    • cites [60] Moritani T, 1979, Am J Phys Med

      Not checked in the free run.

    • cites [20] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    In addition to morphological changes in the muscle, joint mechanical properties such as PTMA may make a small contribution to maximal torque production.

    “In addition to morphological changes in the muscle, joint mechanical properties such as PTMA may make a small contribution to maximal torque production (17, 77).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [17] source

      Not checked in the free run.

    • cites [77] source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductown data

    In the current study, the entire length of the thigh was scanned to accurately identify the ends of the bone and define the precise position of each of a large number of axial images relative to those absolute landmarks to quantify regional differences in muscle size.

    “In the current study, we scanned the entire length of the thigh to accurately identify the ends of the bone and subsequently define the precise position of each of a large number of axial images (slices per muscle: VM, 23–26; VI, 24–27; VL, 24–27; RF, 23–26) relative to those absolute landmarks to carefully quantify regional differences in muscle size.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Changes in lower body ΘP may not continue to adapt with prolonged resistance training and could predominantly occur in the early phase of a training program (i.e., first 3 months).

    “perhaps suggesting that changes in lower body ΘP may not continue to adapt with prolonged RT and could predominantly occur in the early phase of a training program (i.e., first 3 mo).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation

    The difference in MVT of LTT vs. UT was somewhat lower than observed in one previous study (+77%).

    “The difference in MVT of LTT vs. UT in the current study was substantial (+60%), but somewhat lower than observed in one previous study [+77% (70)].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [70] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Architecture measurements were performed in the knee isometric dynamometer with a knee angle of 115°, the same knee joint angle as the strength measurements.

    “Architecture measurements were also performed in the knee isometric dynamometer with a knee angle of 115° (i.e., the same knee joint angle as the strength measurements)”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    After short-term (9 wk) resistance training, maximum voluntary specific tension has been reported to increase by 20%.

    “after short-term (9 wk) RT maximum voluntary specific tension has been reported to increase by 20% (30)”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [30] source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    Regional variability in FL changes, error associated with a single measurement site, differences in the mode of resistance training used, and the short duration of previous reports contribute to the equivocal findings in the literature.

    “Thus it seems likely that the regional variability in FL changes, the error associated with a single measurement site, the differences in the mode of resistance training used and the short duration of previous reports contribute to the equivocal findings in the literature (34).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [34] source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    One previous study of LTT vs. UT reported no differences between groups for FL; however, they assessed FL at only one site, equivalent to the VLMID site, where the present study also observed no differences.

    “One previous study of LTT vs. UT reported no differences between their groups (39); however, they assessed FL at only one site, equivalent to the VLMID site of our experiment, where we also observed no differences between LTT and UT (Fig. 3A).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [39] source

      Not checked in the free run.

32 of 32

  • The authors state this as an assumption.

    There is a linear relationship between EMG amplitude and torque.

    “assuming a linear relationship between EMG amplitude and torque”

  • The paper relies on this without support.

    The long-term resistance-trained group's self-reported training history is accurate.

    “The long-term resistance-trained group (LTT, n = 16, age 22 ± 2 yr; IPAQ: 5,383 ± 1495 metabolic equivalent min/wk) reported (via a detailed questionnaire and follow-up oral discussion) systematic, progressive, heavy RT of the quadriceps ~3 ×/wk for ≥3 yr (mean ± SD, 4 ± 1 yr; range, 3–5 yr)”

  • The paper relies on this without support.

    The untrained control group had no lower-body resistance training experience for more than 18 months.

    “The untrained control group (UT, n = 52, age 25 ± 2 yr; IPAQ: 2,286 ± 1312 metabolic equivalent min/wk) had no lower-body RT experience for >18 mo.”

  • The paper relies on this without support.

    The LTT individuals in the current study had been doing a range of different training practices.

    “as the LTT individuals in the current study had been doing a range of different training practices”

  • The paper relies on this without support.

    No previous studies have examined maximum voluntary specific tension of LTT individuals.

    “none have previously examined maximum voluntary specific tension to investigate the contribution of force per unit area to the enhanced strength of LTT.”

  • The paper relies on this without support.

    This is the first report to quantify the contribution of different aspects of muscle morphology to the enhanced muscle mass of substantially hypertrophied human muscle.

    “To our knowledge this is the first report to quantify the contribution of these different aspects of muscle morphology to the enhanced muscle mass of substantially hypertrophied human muscle”

  • The paper relies on this without support.

    Previous studies typically used a small number of slices and positioned slices based on relatively imprecise surface anatomical measurements.

    “In contrast, previous studies typically used a small number of slices and positioned slices based on relatively imprecise surface anatomical measurements.”

  • The paper relies on this without support.

    No systematic effects interact with potential confounders to influence the comparison of LTT and UT groups within the current study.

    “Therefore, we are not aware of any systematic effects that might interact with these potential confounders and influence the comparison of LTT and UT groups within the current study.”

  • The paper relies on this without support.

    The participants all had the primary goal of increasing maximum strength.

    “Nonetheless these participants all had the primary goal of increasing maximum strength”

  • The paper relies on this without support.

    There are very few supervised resistance training studies of at least 6 months duration.

    “there are very few supervised RT studies of ≥6 mo duration”
10 of 10

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Factors such as fiber types, biomechanical levers, pennation angle, fascicle length and tendon/extracellular matrix composition may all influence the ability to develop muscular force.

    “factors such as fiber types, biomechanical levers, pennation angle, fascicle length and tendon/extracellular matrix composition may all influence the ability to develop muscular force [105].”

    From Transgender Women in the Female Category of Sport: Perspectives on Testosterone Suppression and Performance Advantage (2021) · cites this paper as [105]

    The Introduction links pennation angle to force-generating capacity and identifies fiber-type composition as a possible contributor to contractile specific tension. The Methods use fascicle length in a measure of muscular force production, and the Discussion says joint leverage may contribute to maximal torque. The paper does not address how tendon or extracellular-matrix composition influences force development. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

Cites

Flagged first, then by citations

Research works printed but not linked: 6

  1. 10.1111/j.1469-7793.2001.t01-1-00613.x · DOI · Paper page
  2. Alexander R, 1975, J Hum Mov Stud, 1, 115
  3. Degens H, 2009, J Musculoskelet Neuronal Interact, 9, 123
  4. Erskine RM, 2008, Proc Phys Soc, 11, C89
  5. Gans C, 1965, Ergeb Anat Entwicklungsgesch, 38, 115
  6. Moritani T, 1979, Am J Phys Med, 58, 115

Cited by

Sorted by citations

Related

Authors
Maden-Wilkinson, T. M., Balshaw, T. G., Massey, G. J., & Folland, J. P.
Affiliations
  • Academy of Sport and Physical Activity, Faculty of Health and Wellbeing, Collegiate Campus, Sheffield Hallam University, Sheffield, United Kingdom
  • Loughborough University (GB)
Corresponding author
Folland, Jonathan P.
ORCID
Venue
Journal of Applied Physiology
Publisher
American Physiological Society
Published
2020-04-01
Volume
128
Issue
4
Pages
1000-1011
ISSN
  • 0161-7567 (ISSN-L)
  • 8750-7587
  • 1522-1601
DOI
10.1152/japplphysiol.00224.2019
PMC
PMC7191505
OpenAlex
W2998103558
Semantic Scholar
842e7546bbc48de51dbb4ef379066b4d5e6dc1e1
Cited by
81
References
79
Citations by year
2026: 5 · 2025: 7 · 2024: 11 · 2023: 15 · 2022: 16 · 2021: 13 · 2020: 13
FWCI
11.16
Type
journal article
Language
en
Open access
Licence
cc-by
Locations
  • Journal of Applied Physiology (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • SHURA (Sheffield Hallam University Research Archive) (Sheffield Hallam University) (acceptedVersion)
  • Figshare (submittedVersion, cc-by)
Topics
  • Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports Performance and Training
  • Health Sciences › Medicine › Complementary and alternative medicine › Cardiovascular and exercise physiology
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Muscle Physiology and Disorders
Keywords
resistance training, muscle strength, skeletal muscle morphology, muscle architecture, physiological cross-sectional area, fascicle length, joint mechanics, muscle volume
MeSH terms
Adult, Humans, Isometric Contraction, Muscle, Skeletal, Torque, Quadriceps Muscle, Muscle Strength, Resistance Training, Young Adult

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Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-09.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-09.

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