Effect of Sleep on Cardiorespiratory Fitness of Apparently Healthy Young Adults

Abstract

Background: Sleep dysfunction affects overall health of a person. Exact effect of sleep on cardiorespiratory fitness is less researched area. This study aimed to explore the effect of sleep on cardiorespiratory fitness by examining the difference in VO2 max between normal and poor sleep categories and examine the correlation between PSQI score with VO2 max of young medical students.
Methods: A cross-sectional analytical study was conducted in Clinical Physiology Department, Maharajgunj Medical Campus from March 2023 to September 2024. Participants were categorised into normal and poor sleep categories on the basis of PSQI scores. Participants from both groups performed Queen’s college step test. Heart rate was monitored post exercise to calculate VO2 max. Independent samples t-test was used to compare the VO2 max between the categories. Pearson’s correlation test was used to examine correlation of PSQI score with VO2 max.
Results: A total of 64 participants enrolled in the study out of which 45 were males and 19 were females. Mean PSQI score in male participants was 5.53 ± 2.76 and in female participants was 5.52 ± 3.44. The mean VO2 max in normal sleep category was 42.50 ± 8.61 mL/kg/min and mean VO2 max in poor sleep category was 41.89 ± 7.97 mL/kg/min. There was no significant difference in VO2 max between the two groups (p=0.77). Also, no correlation was found between PSQI score and VO2 max (r=0.029, p=0.591).
Conclusions: Significant impact of sleep quality on cardiorespiratory fitness assessed by VO2 max could not be established in apparently healthy young adults.
Keywords: Cardiorespiratory fitness; Nepal; queen’s college step test; sleep; VO2 max.