title: Does training frequency and supervision affect compliance, performance and muscular health? A cluster randomized controlled trial.
abstract: The aim was to determine the effect of one weekly hour of specific strength training within working hours, performed with the same total training volume but with different training frequencies and durations, or with different levels of supervision, on compliance, muscle health and performance, behavior and work performance. In total, 573 office workers were cluster-randomized to: 1 WS: one 60-min supervised session/week, 3 WS: three 20-min supervised sessions/week, 9 WS: nine 7-min supervised sessions/week, 3 MS: three 20-min sessions/week with minimal supervision, or REF: a reference group without training. Outcomes were diary-based compliance, total training volume, muscle performance and questionnaire-based health, behavior and work performance. Comparisons were made among the WS training groups and between 3 WS and 3 MS. If no difference, training groups were collapsed (TG) and compared with REF. Results demonstrated similar degrees of compliance, mean(range) of 39(33-44)%, and total training volume, 13.266(11.977-15.096)kg. Musculoskeletal pain in neck and shoulders were reduced with approx. 50% in TG, which was significant compared with REF. Only the training groups improved significantly their muscle strength 8(4-13)% and endurance 27(12-37)%, both being significant compared with REF. No change in workability, productivity or self-rated health was demonstrated. Secondary analysis showed exercise self-efficacy to be a significant predictor of compliance. Regardless of training schedule and supervision, similar degrees of compliance were shown together with reduced musculoskeletal pain and improved muscle performance. These findings provide evidence that a great degree of flexibility is legitimate for companies in planning future implementation of physical exercise programs at the workplace. ClinicalTrials.gov, number NCT01027390.
authors: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark. Electronic address: tdalager@health.sdu.dk.
authors: Tina
authors: T
authors: Dalager
authors: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark. Electronic address: tbredahl@health.sdu.dk.
authors: Thomas G V
authors: TG
authors: Bredahl
authors: Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark. Electronic address: mtpedersen@nexs.ku.dk.
authors: Mogens T
authors: MT
authors: Pedersen
authors: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark. Electronic address: eboyle@health.sdu.dk.
authors: Eleanor
authors: E
authors: Boyle
authors: National Research Centre for the Working Environment, Copenhagen, Denmark. Electronic address: lla@arbejdsmiljoforskning.dk.
authors: Lars L
authors: LL
authors: Andersen
authors: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark. Electronic address: gsjogaard@health.sdu.dk.
authors: Gisela
authors: G
authors: Sjøgaard
mesh_terms: D000328:Adult; D016000:Cluster Analysis; D003718:Denmark; D004650:Employee Performance Appraisal; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D059352:Musculoskeletal Pain / Q000175:diagnosis / Q000534:rehabilitation*; D009934:Organization and Administration; D010349:Patient Compliance / Q000706:statistics & numerical data*; D055070:Resistance Training / Q000379:methods*; D012720:Severity of Illness Index; D016037:Single-Blind Method; D013647:Task Performance and Analysis; D013997:Time Factors; D017132:Workplace
keywords: Exercise self-efficacy; Physical activity; Strength training; Workplace intervention