Two 15‑Minute Naps on the Night Shift: Effects on Sleepiness, Fatigue, and HRV
Summary
This field study followed 15 night-shift nurses to test whether two 15-minute naps during a shift could improve alertness and physiological stress markers. While both nap and no-nap groups reported rising fatigue and sleepiness toward early morning, the nap group showed more stable heart rate variability, with a lower LF/HF ratio and no sudden morning spike in parasympathetic activity. These findings suggest short naps may help reduce physiological strain even if they don’t immediately change how tired workers feel.
Why It Matters For Night Shift Workers and Night Owls
For night-shift nurses, this study shows that very short naps can support the body’s stress response during overnight hours. Even though workers still felt sleepy, naps helped keep the heart and nervous system more balanced, which may reduce strain and improve recovery. For individuals, it suggests that quick rest breaks can benefit health even if you don’t feel more awake afterward. For workplaces, it highlights the value of scheduling short nap breaks to protect long-term well-being and safety.
Notes
Includes HRV/sympathetic activity outcomes.