Cited by 65Muscle metabolism and nutritionCardiovascular and exercise physiologyExercise and Physiological Responses

Acute molecular responses to concurrent resistance and high-intensity interval exercise in untrained skeletal muscle

Open access
Pugh, Jamie K., Faulkner, Steve H., Jackson, Andrew P., King, James A., Nimmo, Myra A.·2015·Physiological Reports

Abstract

Concurrent training involving resistance and endurance exercise may augment the benefits of single-mode training for the purpose of improving health. However, muscle adaptations, associated with resistance exercise, may be blunted by a subsequent bout of endurance exercise, via molecular interference. High-intensity interval training (HIIT), generating similar adaptations to endurance exercise, may offer an alternative exercise mode to traditional endurance exercise. This study examined the influence of an acute HIIT session on the molecular responses following resistance exercise in untrained skeletal muscle. Ten male participants performed resistance exercise (4 × 8 leg extensions, 70% 1RM, (RE)) or RE followed by HIIT (10 × 1 min at 90% HRmax, (RE+HIIT)). Muscle biopsies were collected from the vastus lateralis before, 2 and 6 h post-RE to determine intramuscular protein phosphorylation and mRNA responses. Phosphorylation of Akt (Ser(473)) decreased at 6 h in both trials (P < 0.05). Phosphorylation of mTOR (Ser(2448)) was higher in RE+HIIT (P < 0.05). All PGC-1α mRNA variants increased at 2 h in RE+HIIT with PGC-1α and PGC-1α-ex1b remaining elevated at 6 h, whereas RE-induced increases at 2 and 6 h for PGC-1α-ex1b only (P < 0.05). Myostatin expression decreased at 2 and 6 h in both trials (P < 0.05). MuRF-1 was elevated in RE+HIIT versus RE at 2 and 6 h (P < 0.05). Atrogin-1 was lower at 2 h, with FOXO3A downregulated at 6 h (P < 0.05). These data do not support the existence of an acute interference effect on protein signaling and mRNA expression, and suggest that HIIT may be an alternative to endurance exercise when performed after resistance exercise in the same training session to optimize adaptations.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.14814/phy2.12364

Cites

76 of 76 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

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?

  • When exhaustive endurance exercise (such as high-intensity interval training or prolonged cycling) is performed in close temporal proximity to resistance training, the profound depletion of intramuscular glycogen and elevation of the AMP:ATP ratio robustly activate AMPK.

    “When exhaustive endurance exercise (such as high-intensity interval training or prolonged cycling) is performed in close temporal proximity to resistance training, the profound depletion of intramuscular glycogen and elevation of the AMP:ATP ratio robustly activate AMPK [134,135].”

    From Ribosome Biogenesis as a Putative Bottleneck to Skeletal Muscle Hypertrophy: Mechanisms, Human Evidence, and Practical Modulators (2026) · cites this paper as [134]

    The Introduction (page unavailable) says AMPK activation occurs during endurance exercise and may be involved when endurance and resistance exercise are combined. It does not say that glycogen depletion or an elevated AMP:ATP ratio causes robust AMPK activation in closely timed sessions. The Methods’ statistical-analysis passage lists the signaling proteins measured and does not include AMPK. (LLM, conf=0.86)

    Experimental — accuracy not yet measured
  • The synthesis of a mature 80S ribosome requires the stoichiometric orchestration of three RNA polymerases and the transcription of thousands of massive pre-rRNA precursors, arguably making it the most ATP-demanding process within a muscle fiber.

    “The synthesis of a mature 80S ribosome requires the stoichiometric orchestration of three RNA polymerases and the transcription of thousands of massive pre-rRNA precursors, arguably making it the most ATP-demanding process within a muscle fiber [32,134].”

    From Ribosome Biogenesis as a Putative Bottleneck to Skeletal Muscle Hypertrophy: Mechanisms, Human Evidence, and Practical Modulators (2026) · cites this paper as [134]

    Split into 2 atoms — 0 confirmed, 0 partially supported, 0 disputed, 0 misattributed, 2 unverifiable. Expand the claim to see per-atom verdicts.

    Experimental — accuracy not yet measured

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Chief Medical Office 2011 Physical Activity Guidelines in the UK: Review and Recommendations

Cited by

Sorted by citations

Authors
Pugh, J. K., Faulkner, S. H., Jackson, A. P., King, J. A., & Nimmo, M. A.
Affiliations
Loughborough University (GB)
Corresponding author
Nimmo, Myra A.
Venue
Physiological Reports
Publisher
Wiley
Published
2015-04
Volume
3
Issue
4
Pages
e12364
ISSN
2051-817X (ISSN-L)
OpenAlex
W2122169207
Cited by
63
References
75
Citations by year
2026: 6 · 2025: 1 · 2024: 3 · 2023: 9 · 2022: 2 · 2021: 3 · 2020: 11 · 2019: 2 · 2018: 7 · 2017: 9 · 2016: 6 · 2015: 4
FWCI
4.61
Type
journal article
Language
en
Open access
Locations
  • Physiological Reports (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Nottingham Trent University's Institutional Repository (Nottingham Trent Repository) (acceptedVersion)
  • Loughborough University Institutional Repository (Loughborough University) (submittedVersion, cc-by)
  • Loughborough University Research Repository (Loughborough University) (submittedVersion, cc-by)
  • University of Birmingham Research Portal (University of Birmingham) (submittedVersion, cc-by)
Funders
  • Technogym
  • The Wellness Company
  • National Institute for Health Research (NIHR) Diet, Lifestyle & Physical Activity Biomedical Research Unit
  • University Hospitals of Leicester
  • Loughborough University
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
  • Health Sciences › Medicine › Complementary and alternative medicine › Cardiovascular and exercise physiology
  • Health Sciences › Medicine › Rehabilitation › Exercise and Physiological Responses
Keywords
concurrent training, resistance training, high-intensity interval training, endurance exercise, vastus lateralis, protein phosphorylation, Akt, mTOR, PGC-1α, myostatin, MuRF1, atrogin-1, FOXO3, muscle protein degradation, mRNA expression

About these checks

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.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review