Introduction: Exercise-induced dehydration (EID) is associated with impairments in aerobic and anaerobic exercise performance primarily due to disturbance of the physiological function of the cardiovascular and central nervous systems and metabolic pathways. Regardless, dehydration is often used to manipulate mass in sports with strict mass categories to be adhered to, such as boxing. Although the impact of dehydration has been assessed in endurance exercise, little is known about the potential for performance enhancement over short durations, particularly when body mass is a key determinant of performance. One such example is UK hill climb cycling where races are ~60-300s in duration. Aims and Hypothesis: This study aimed to reduce body mass via a fluid restriction (FR) and EID intervention and monitor the effects on the power output normalised to body mass during short duration, maximal exercise such as experienced by hill climb cyclists. It was hypothesised that despite dehydration causing a decrease in raw power output (W), the drop in body mass would be sufficient to result in a significantly increased normalised power (W/kg). Methods: 10 well-trained cyclists (Mean±SD: 36±16 years, 77±13kg, 179±10cm and VO2max 44±3ml/kg/min) performed a short, 180s maximal cycling exercise test (SMET) on two separate days in either a euhydrated (EUH) or dehydrated (DEH) condition. Dehydration was induced via overnight FR and EID wearing an insulated bodysuit. The order of testing was randomised. Power output (W) was recorded during the SMET and normalised to body mass (W/kg) and reported at 5, 30, 60, 90, 120, 150 and 180s. Paired samples t-tests were used to compare conditions. Results: Mean body mass decreased by 2.02±1.28% following dehydration. Although raw power fell at all time points except 5 and 30s, the reductions in body mass resulted in small but significant increases in normalised power at 5 and 30s, no change at 60, 90, 120 or 150s and a significant reduction in normalised power at 180s (Table 1). Discussion: Despite dehydration reducing raw power output overall, the fall in body mass resulted in no significant detriment to normalised power up to 150s of exercise. Beyond this timepoint, the physiological effects of dehydration overwhelmed the ergogenic effects of decreased body mass and led to a drop in normalised power. In conclusion dehydration may be a viable performance enhancement strategy for short events less than 150s in duration when normalised power is a key determinant of performance.