[Truncated abstract] Broadly, research literature on the physiological aspects of water polo game play is limited, but particularly so in the women's game. Moreover, significant changes to game rules in recent years are likely to have had an impact on the game demands. Therefore, this research project sought to investigate the physiological characteristics of contemporary elite female water polo players and the demands of match play. Overall, the five studies comprising this thesis aimed to improve the practical knowledge of coaches and sport scientists concerning the training and monitoring of players. Study one (Chapter 3) compared two water polo-specific field tests of aerobic and/or match fitness (MSST, multistage shuttle swim test; and WIST, water polo intermittent shuttle test) with a traditional incremental swimming test to exhaustion (IST, 5 x 200 m). Prior to this study, the physiological responses to the MSST and WIST were not well understood. Additionally, the degree of association between these two tests was unknown. Therefore, 14 Australian National Women's Water Polo Squad players performed the MSST and WIST, and 13 players from a National Water Polo League club performed the MSST, WIST and IST, on separate occasions. Peak heart rate, blood lactate and ratings of perceived exertion were obtained for all tests. Expired air was collected post test for the National League players. The results showed that the National Squad players performed significantly better in the MSST (636 ± 114 vs. 437 ± 118 m, p < 0.001) and WIST (270 ± 117 vs. 115 ± 57 m, p < 0.001) than the National League players. ... Absolute decrement yielded TE of 0.55 s (-0.42-0.81), CV of 26.0% (19.3-41.0) and ICC of -0.002 (-0.44-0.44). Relative (%) decrement yielded TE of 1.6% (1.2-2.3), CV of 27.2% (20.1-42.9) and ICC of -0.02 (-0.46-0.42). Results indicate that total time was a reliable measure, whilst decrement was not. Similar to land-based RSA tests, total time should be the criterion measure of performance in the RST. The RST can form part of a specific battery of field tests for water polo, and can also be used as a conditioning tool. The final study (Chapter 7) was a nutritional-intervention study. Based on the time-motion data from study three, a 59-min match simulation test (MST) was designed to mimic the activity profiles and physical demands of water polo match play. Using a randomized cross-over double-blind design, 12 Australian National Women's Water Polo Squad players ingested 0.3 g·kg-1 of NaHCO3 or placebo, 90 min before performing the MST, which included 56 x 10-m maximal-sprint swims as the performance measure. Although pre-exercise ingestion of NaHCO3 was effective in enhancing extracellular pH and bicarbonate levels, the percentage difference in mean sprint times between trials showed no substantial effects of NaHCO3 (0.4; ±0.9%, effect size = 0.09; ±0.23, p = 0.51). The results suggest that elite water polo players should not expect enhancement in intermittent-sprint performance from NaHCO3 supplementation. These findings are contrary to previous NaHCO3 studies on simulated team-sport performance, but this investigation is unique in that it examined highly-trained athletes performing sport-specific tasks. In conclusion, the findings of this thesis add to the existing literature on the applied physiology of women's water polo. It is hoped that the knowledge gained from these findings will lead to more appropriate conditioning, testing and selection outcomes.