Muscular adaptations and insulin‐like growth factor‐1 responses to resistance training are stretch‐mediated. Issue 1 (30th October 2013)

• Record Type: Journal Article
• Authors: McMahon, Gerard; Morse, Christopher I.; Burden, Adrian; Winwood, Keith; Onambélé, Gladys Leopoldine
• Is Part Of: Muscle & nerve. Volume 49:Issue 1(2014:Jan.)
• Page Start: 108
• Page End: 119
• Publication Date: 2013-10-30
• Subjects: Neuromuscular diseases -- Periodicals; Muscles -- Periodicals; Nerves -- Periodicals; 616.74
• DOI: 10.1002/mus.23884
• Languages: English
• ISSNs: 0148-639X

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p> <italic>Introduction</italic>: Modulation of muscle characteristics was attempted through altering muscle stretch during resistance training. We hypothesized that stretch would enhance muscle responses. <italic>Methods</italic>: Participants trained for 8 weeks, loading the quadriceps in a shortened (SL, 0–50° knee flexion; <italic>n</italic> = 10) or lengthened (LL, 40–90°; <italic>n</italic> = 11) position, followed by 4 weeks of detraining. Controls (CON; <italic>n</italic> = 10) were untrained. Quadriceps strength, vastus lateralis architecture, anatomical cross‐sectional area (aCSA), and serum insulin‐like growth factor‐1 (IGF‐1) were measured at weeks 0, 8, 10, and 12. <italic>Results</italic>: Increases in fascicle length (29 ± 4% vs. 14 ± 4%), distal aCSA (53 ± 12% vs. 18 ± 8%), strength (26 ± 6% vs. 7 ± 3%), and IGF‐1 (31 ± 6% vs. 7 ± 6%) were greater in LL compared with SL muscles (<italic>P</italic> &lt; 0.05). No changes occurred in CON. Detraining decrements in strength and aCSA were greater in SL than LL muscles (<italic>P</italic> &lt; 0.05). <italic>Conclusions</italic>: Enhanced muscle <italic>in vivo</italic> (and somewhat IGF‐1) adaptations to resistance training are concurrent with muscle stretch, which warrants its inclusion within training. <italic>Muscle Nerve</italic><bold>49</bold>: 108–119, 2014</p> </abstract>