The Study: Relationship between sleep and muscle strength among Chinese university students: a cross-sectional study              

 The Facts: 

a. “Poor sleep quality and short sleep duration are associated with an increased risk for muscle mass reduction.” 

b. The authors noted that a previous study had suggested that short sleep duration was associated with increased inflammation in adolescents. 

c. They also indicate that sleep disruption was associated with impaired secretion of insulin-like growth factor-1. 

d. Additionally they note that increased inflammation is a risk for lower muscle strength and that insulin-like growth factor-1 modulates both muscle mass and muscle function.  

e. They also note previous studies showing a relationship between muscle mass and sleep.  

f. This study examined both sleep quality and duration and their relationship to muscle strength.  

g. The subjects were 10,125 female and male university students. 

h. Strength was assessed using a hand grip dynamometer. 

i. Sleep quality and length were assessed with self-reporting. 

j. “…a positive association between sleep quality and muscle strength was observed in both male and female students.” 

k. Male subjects who were sleeping 6 hours were measurably weaker than those who slept 7 to 8 hours. 

l. No significant difference was noted between those men who slept 7 to 8 hours and those who slept more than 8 hours. 

m. In the women, although there was an association between sleep quality and strength there was not a significant association between sleep duration and strength. 

 Take Home:

Sleep quality and duration are both factors that can affect muscular function however, the exact ways in which sleep disruptions may impact strength seem to differ between men and women.   

Reviewer's Comments:

The authors note previous studies relating disruptions of sleep in women to hormonal changes during the normal menstrual cycle and may partially explain some of the differences in how strength was affected in women vs. men. They also noted that self-reported sleep quality and duration were used in previous studies as opposed to actually measuring them so there could have been some decrease in accuracy. 

First, there are limitations in all studies. But I think we often don’t give enough credit to the importance of sleep to our health. (Some of us have spent decades getting by on three hours sleep per night!) I now sleep a lot more unless there’s something good on Hallmark’s Movies and Mysteries or a great old movie on Turner Classic Movies. In fact   I’m sure I’ll be watching “It Happened on Fifth Avenue” on Christmas Eve.  God bless us everyone. I wish everyone a Merry Christmas.

 Reviewer:  Roger Coleman DC

Editor’s Comments: I was a week late getting this article posted, but I hope all our readers had a wonderful Christmas holiday. We wish you all a successful and happy New Year. 

Editor: Mark R. Payne DC

Reference: Y Chen, Y Cui, S Chen, Z Wu. Relationship between sleep and muscle strength among Chinese university students: a cross-sectional study. J Musculoskeletal Neuronal Interact. 2017 Dec 1;17(4):327-333  

Link to Abstract: https://pubmed.ncbi.nlm.nih.gov/29199194/  

Link to Full Text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5749041/