{ "abstract": "Objective: Muscle weakness is prevalent in rheumatoid arthritis (RA), osteoarthritis (OA) and sarcopenia (SARC). Endurance exercises may improve mitochondrial function and oxidative capacity, while strength exercises are thought to stimulate myofibrillar protein synthesis. This study aims to compare the effects of strength and endurance exercise and explore the association between muscle characteristics and exercise outcomes in patients with RA, OA and SARC. We hypothesize that responses to endurance and strength exercises in patients with muscle weakness are influenced by intramuscular pathology including muscle morphology, mitochondrial function, and systemic inflammation, based on their disease pathology, potentially requiring personalized training schedules. Methods: This two-arm, parallel-group exploratory trial will enroll 69 patients (23 RA, 23 OA, 23 SARC), randomized to endurance (n = 35) or muscle strength exercises (n = 34), using minimization to balance disease type and gender. The 8-week intervention includes two supervised sessions per week using a controlled cable pulley device (Reforter™) and fitness equipment, plus one weekly home-based session. The primary outcome is isokinetic muscle strength (peak torque), measured with the Biodex system®. Secondary outcomes include muscle morphology, mitochondrial function, systemic inflammation and muscle endurance (by Biodex and 6 Minute Walk test). Muscle morphology will be assessed via 3D ultrasound imaging of the vastus lateralis. Mitochondrial function will be analyzed using high-resolution respirometry on muscle biopsies. Systemic inflammation will be measured using multiplex assays or ELISA on serum samples. Discussion: This study will explore differential responses to muscle endurance and muscle strength exercises in patients with RA, OA, and SARC, offering novel insights into the molecular mechanisms of muscle weakness. The findings may help identify potential mechanisms underlying variability in exercise response and provide effect size estimates to guide future confirmatory studies and more targeted exercise interventions. Trial registration: ClinicalTrials.gov NCT06480643 (date of registration28-06-24).", "abstract_shown": true, "affiliations": [ "Amsterdam University Medical Center, Department of Rehabilitation Medicine, Location VU University Medical Center, Amsterdam, The Netherlands", "Reade, Center for Rehabilitation and Rheumatology, Amsterdam, The Netherlands", "Amsterdam University Medical Center, Department of Rheumatology and Clinical Immunology, Location VU Medical Center, Amsterdam, The Netherlands", "Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands", "Vrije Universiteit Amsterdam, Laboratory for Myology, Department of Human Movement Sciences, Faculty of Behavioral and Movement Sciences, Amsterdam Movement Sciences, Amsterdam, The Netherlands", "Amsterdam University of Applied Sciences, Center of Expertise Urban Vitality, Faculty of Health, Sport and Physical Activity, Amsterdam, The Netherlands" ], "article_type": "Study Protocol", "arxiv": null, "author_total": 10, "authors": [ { "affs": [ 0 ], "name": "Maia M. Sobejana" }, { "affs": [ 1 ], "name": "Rosa M. Korpershoek" }, { "affs": [ 2 ], "name": "Maarten M. Steinz" }, { "affs": [ 3 ], "name": "Conny J. van der Laken" }, { "affs": [ 4 ], "name": "Marike van der Leeden" }, { "affs": [ 5 ], "name": "Richard T. Jaspers" }, { "name": "Bart Visser" }, { "name": "Martin van der Esch" }, { "name": "Carel G. M. Meskers" }, { "name": "Mariëtte de Rooij" } ], "bibtex": "https://research.draconitic.com/paper/ff42435b2qeby.bib", "cited_by": 0, "doi": "10.1371/journal.pone.0356181", "fulltext_url": null, "id": "ff42435b2qeby", "issns": [ "1932-6203" ], "landing_url": "https://doi.org/10.1371/journal.pone.0356181", "language": null, "licence": "CC-BY-4.0", "licence_label": "CC BY 4.0", "licence_source": "journal", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "openalex", "2737|Nutrition and Health in Aging" ], [ "plos", "/Biology and life sciences/Biochemistry/Bioenergetics/Energy-producing organelles/Mitochondria" ], [ "plos", "/Biology and life sciences/Cell biology/Cellular structures and organelles/Energy-producing organelles/Mitochondria" ], [ "plos", "/Biology and life sciences/Immunology/Clinical immunology/Autoimmune diseases/Rheumatoid arthritis" ], [ "plos", "/Biology and life sciences/Immunology/Immune response/Inflammation" ], [ "plos", "/Biology and life sciences/Physiology/Muscle physiology/Muscle functions" ], [ "plos", "/Biology and life sciences/Sports science/Sports and exercise medicine/Exercise" ], [ "plos", "/Biology and life sciences/Sports science/Sports and exercise medicine/Exercise/Strength training" ], [ "plos", "/Medicine and health sciences/Clinical medicine/Clinical immunology/Autoimmune diseases/Rheumatoid arthritis" ], [ "plos", "/Medicine and health sciences/Clinical medicine/Signs and symptoms/Inflammation" ], [ "plos", "/Medicine and health sciences/Immunology/Clinical immunology/Autoimmune diseases/Rheumatoid arthritis" ], [ "plos", "/Medicine and health sciences/Immunology/Immune response/Inflammation" ], [ "plos", "/Medicine and health sciences/Public and occupational health/Physical activity/Physical fitness/Exercise" ], [ "plos", "/Medicine and health sciences/Public and occupational health/Physical activity/Physical fitness/Exercise/Strength training" ], [ "plos", "/Medicine and health sciences/Rheumatology/Arthritis/Osteoarthritis" ], [ "plos", "/Medicine and health sciences/Rheumatology/Arthritis/Rheumatoid arthritis" ], [ "plos", "/Medicine and health sciences/Sports and exercise medicine/Exercise" ], [ "plos", "/Medicine and health sciences/Sports and exercise medicine/Exercise/Strength training" ], [ "plos", "/Research and analysis methods/Bioassays and physiological analysis/Muscle analysis" ] ], "openalex": "W7211997991", "pdf_url": "https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0356181&type=printable", "pmcid": null, "pmid": null, "published": "2026-09-09", "publisher": "Public Library of Science", "ris": "https://research.draconitic.com/paper/ff42435b2qeby.ris", "sources": [ { "first_seen": "2026-10-30T12:17:56Z", "native_id": "10.1371/journal.pone.0356181", "source": "plos", "url": "https://doi.org/10.1371/journal.pone.0356181" } ], "subjects": [ { "field": "biology", "origin": "plos:immunology", "subfield": "immunology" }, { "field": "medicine", "origin": "plos:public and occupational health", "subfield": "epidemiology-public-health" } ], "title": "Effects of exercise on muscle strength and characteristics in rheumatic diseases and sarcopenia: Protocol for the Care for Muscle (C4M) Study", "title_text": "Effects of exercise on muscle strength and characteristics in rheumatic diseases and sarcopenia: Protocol for the Care for Muscle (C4M) Study", "type": "peer-reviewed", "updated_at": "2026-10-30T12:17:56Z", "url": "https://research.draconitic.com/paper/ff42435b2qeby", "venue": "PLOS One", "versions": [] }