One week of step reduction lowers myofibrillar protein synthesis rates in young men
Journal article
Shad, Brandon J., Thompson, Janice L., Holwerda, Andrew M., Stocks, Ben, Elhassan, Yasir S., Philp, Andrew, Van Loon, Luc J. C. and Wallis, Gareth A.. (2019). One week of step reduction lowers myofibrillar protein synthesis rates in young men. Medicine and Science in Sports and Exercise. 51(10), pp. 2125 - 2134. https://doi.org/10.1249/MSS.0000000000002034
Authors | Shad, Brandon J., Thompson, Janice L., Holwerda, Andrew M., Stocks, Ben, Elhassan, Yasir S., Philp, Andrew, Van Loon, Luc J. C. and Wallis, Gareth A. |
---|---|
Abstract | Purpose Across the lifespan, physical activity levels decrease and time spent sedentary typically increases. However, little is known about the impact that these behavioral changes have on skeletal muscle mass regulation. The primary aim of this study was to use a step reduction model to determine the impact of reduced physical activity and increased sedentary time on daily myofibrillar protein synthesis rates in healthy young men. Methods Eleven men (22 ± 2 yr) completed 7 d of habitual physical activity (HPA) followed by 7 d of step reduction (SR). Myofibrillar protein synthesis rates were determined during HPA and SR using the deuterated water (2H2O) method combined with the collection of skeletal muscle biopsies and daily saliva samples. Gene expression of selected proteins related to muscle mass regulation and oxidative metabolism were determined via real time reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Results Daily step count was reduced by approximately 91% during SR (from 13,054 ± 2763 steps per day to 1192 ± 330 steps per day; P < 0.001) and this led to an increased contribution of sedentary time to daily activity (73% ± 6% to 90% ± 3%; P < 0.001). Daily myofibrillar protein synthesis decreased by approximately 27% from 1.39 ± 0.32%·d−1 during HPA to 1.01 ± 0.38%·d−1 during SR (P < 0.05). Muscle atrophy F-box and myostatin mRNA expression were upregulated, whereas mechanistic target of rapamycin, p53, and PDK4 mRNA expression were downregulated after SR (P < 0.05). Conclusions One week of reduced physical activity and increased sedentary time substantially lowers daily myofibrillar protein synthesis rates in healthy young men. |
Keywords | skeletal muscle; physical activity; inactivity; sedentary |
Year | 2019 |
Journal | Medicine and Science in Sports and Exercise |
Journal citation | 51 (10), pp. 2125 - 2134 |
Publisher | Lippincott Williams & Wilkins |
ISSN | 0195-9131 |
Digital Object Identifier (DOI) | https://doi.org/10.1249/MSS.0000000000002034 |
Scopus EID | 2-s2.0-85072171743 |
Open access | Open access |
Page range | 2125 - 2134 |
Research Group | Mary MacKillop Institute for Health Research |
Author's accepted manuscript | License |
Publisher's version | |
Place of publication | United States of America |
https://acuresearchbank.acu.edu.au/item/8q628/one-week-of-step-reduction-lowers-myofibrillar-protein-synthesis-rates-in-young-men
Download files
Author's accepted manuscript
AM_Shad_2019_One_week_of_step_reduction_lowers.pdf | |
License: CC BY-NC 4.0 |
Publisher's version
305
total views413
total downloads1
views this month4
downloads this month