I'hirty-two male subjects were randomly assigned to one of four groups. Groups A and B were pre-loaded with glucose, Groups C and D were not. Groups A and D carried out a pursuit rotor task under 50 dBA (non-stressful), white noise. Groups B and C carried out the same task under SOdBA (stressful) white noise. Blood samples were taken from eeoh subject, and blood glucose levels as well as time on target were measured.Statistical analysis of the results showed that noise stress impaired performance and that pre-loading with glucose attenuated the impairment. This change in performance was accompanied by 6 reduction in the high blood glucose level caused by pre-loading. Pre-loading in the non-stressful condition impaired performance without an associated faU in the high blood glucose level. A suggestion is made that blood glucose levels may be used as an indicant of stress.