BURGE, C. M., M. F. CAREY, and W. R. PAYNE. Rowing performance, fluid balance and metabolic function following dehydration and rehydration. Med. Sci. Sports Exerc., Vol. 25, No. 12, pp. 1358–1364, 1993. Eight international class lightweight rowers were examined to determine the efficacy of rehydrating with water following 24 h of dehydration on body fluid balance, metabolic function, and rowing performance. The rowers performed a maximal rowing trial on a Gjessing rowing ergometer (4200 revs, 3-kg resistance) while euhydrated (ET) and following partial rehydration (RT). Body weight was reduced using exercise together with food and fluid restriction over 24 h and was followed by consumption of 1.5 1 of water over 2 h. Body weight decreased 5.16 ± 0.14% (P < 0.05) and plasma volume decreased 12.5 ± 1.4% (P < 0.05) after dehydration. Rehydration restored plasma volume by 6.02 ± 0.62%. Rowing trial time increased significantly from 7.02 ±0.17 min for the ET to 7.38 ± 0.21 min for the RT (P < 0.05). The net plasma lactate accumulation decreased significantly from 8.77 ± 0.31 mmol.1-1 for the ET to 6.77 ± 0.24 mmol.1-1 for the RT (P < 0.05). Glycogen content (glycosyl units) of the vastus lateralis decreased by 203.6 ± 18.6 mmol.kg-1 DW during the ET compared with 139.9 ± 13.4 mmol.kg-1 DW during the RT (P < 0.05). These results demonstrate that the dehydration/rehydration protocol reduced maximal rowing performance due to lowered plasma volume and decreased muscle glycogen utilization.