Effect of Acute Sleep Fragmentation on Skeletal Muscle Blood Flow During Handgrip Exercise

Authors

Gabriel Narvaez, Texas Tech UniversityFollow
Joaquin Gonzales, Texas Tech UniversityFollow

Abstract

Sleep fragmentation (arousals from sleep) has been shown to impair vascular function due to elevated inflammation and oxidative stress. Previous research on this topic has focused on resting vascular function, with little information available about the effect of poor sleep on hyperemic responses to exercise. PURPOSE: To test the hypothesis that acute sleep fragmentation impairs skeletal muscle blood flow during exercise. METHODS: Fifteen adults (7F, 8M, age- 25 ± 5 y, BMI 23.5 ± 2.5 kg/m2) participated in a randomized crossover study that included one night of habitual sleep and one night of sleep fragmentation separated by at least 7 days washout period. Sleep was assessed at home by wrist actigraphy. Arousals from sleep was increased by an audio alarm that went off every 30 minutes during the night.  In the laboratory, forearm blood flow (FBF) was measured using Doppler ultrasound with participants in the supine position.  Handgrip exercise was performed with the right hand using an electronic force transducer and consisted of single contractions and rhythmic exercise both performed at 15%, 30%, and 45% MVC. Single 1-second contractions were performed with the 30 cardiac cycles post-contraction included in analysis and 2 minutes of rest between contractions. Rhythmic handgrip exercise was performed for 3 minutes with the last 30-second average included in analysis and each intensity separated by 5 minutes of rest. Paired sample t-tests and Wilcoxon Signed Rank tests were used to compare sleep variables and resting blood flow. A two-way repeated measures ANOVA was used to compare changes in blood flow from rest (FBF) following single contractions and rhythmic exercise (sleep condition x intensity). Normally distributed data is presented as mean ± SD and non-normally distributed data presented as median (interquartile range).  RESULTS: Time in bed on the night of habitual sleep (443 ± 50 min) and the night of fragmented sleep were similar (443 ± 45 min, p=0.96). Wake after sleep onset, index of disrupted sleep, was significantly greater following sleep fragmentation compared to habitual sleep [63 (42, 92) to 117 (89, 138) min, p

Recommended Citation

Narvaez, Gabriel and Gonzales, Joaquin (2026) "Effect of Acute Sleep Fragmentation on Skeletal Muscle Blood Flow During Handgrip Exercise," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 18, Article 34.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss18/34