Cognitive Performance during Successive Sustained Physical Work Episodes
NAVAL HEALTH RESEARCH CENTER SAN DIEGO CA
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During times of emergency, e.g., military operations, humans must often work continuously for long hours at physically demanding tasks while remaining mentally alert. In this repeated measures study, eleven pairs one experimental and one control of Marines N22 experienced one 12-hour baseline and two 20-hour continuous work episodes CWE. The 20-hour CWEs were separated by five hours which included a 3-hour nap from 0400-0700. Each hour of CWE was split into two half-hour sessions. During the first half-hour subjects performed alpha-numeric A-N visual vigilance tasks. The experimental member of each pair spent this first 30 minutes also walking on a treadmill in full combat gear 25 kg at approximately 30 percent max V02 heart rate for a total distance of approximately 114 km. The controls performed the A-N task sitting quietly at a video terminal. During the second half-hour, all subjects performed selected combinations of computer generated tasks. The results indicated that the exercise of treadmill walking did not accentuate sleep loss effects on the cognitive measures studied. Sleep loss day differences was significant for the visual vigilance task CWl 80.9, correct CW2 70.6.
- Anatomy and Physiology