Napping Plus Caffeine: Laboratory and Field Studies in Shift Workers
Summary
This research combined a randomized laboratory study and a field trial to test naps, caffeine, and their combination as countermeasures for night-shift fatigue. In the lab, 68 healthy adults were assigned to one of four groups: nap only, caffeine only, nap plus caffeine, or placebo. All active strategies improved alertness and reaction times compared with placebo, but the combined approach produced the strongest benefits. In the field study with 53 shift workers, naps plus caffeine similarly reduced sleepiness and improved performance during night shifts.
Why It Matters For Night Shift Workers and Night Owls
This study demonstrates that using naps and caffeine together is more effective than relying on either alone. Naps help recover lost sleep, while caffeine provides a temporary boost in alertness, and the combination delivers stronger protection against fatigue. For night-shift workers, this suggests a practical strategy: take a short nap before or during a shift and follow with caffeine for sustained performance. For workplaces, the findings highlight the value of supporting combined countermeasures as part of fatigue management programs.
Notes
Classic shift‑work countermeasure data.