In this study, we aimed to investigate physiological determinants of endurance performance that best predict 5000-m average run velocity before and after endurance training. Thirty-nine previously untrained participants completed a 5000-m run; a constant velocity test (measuring running economy); and an incremental treadmill test to determine maximal oxygen uptake, final treadmill velocity, and velocity and oxygen uptake at lactate threshold, before and after six weeks of endurance training. Maximal oxygen uptake, final treadmill velocity, and velocity and oxygen uptake at threshold all increased significantly after training (p < 0.05). Average velocity for 5000 m increased significantly (p < 0.05). Running economy was not significantly altered. Correlation analysis revealed final treadmill velocity was most strongly related to 5000-m performance, in both untrained and trained states (r = 0.89, 0.83). Lactate threshold velocity (r = 0.73, 0.76), maximal oxygen uptake (r = 0.55, 0.51) and oxygen uptake at threshold (r = 0.45, 0.45) also showed significant correlations. In contrast, running economy was not significantly related to performance. These results demonstrate that final treadmill velocity in an VO2max test is the single best predictor of 5000-m performance in untrained and trained states. Furthermore, stepwise regression analysis showed that only velocity at lactate threshold significantly improved the accuracy of prediction provided by final treadmill velocity alone.

Little is known about the relationship between real and perceived water competence among youth in the context of drowning prevention or of their perceptions of their risk of drowning. This study reports the findings of an international project entitled Can You Swim? Collegiate physical education students (n = 373) were assessed in a two-part study using an initial questionnaire survey to provide self-estimates of water competency and risk perception, followed by six practical tests in the water. Correlation coefficients between perceived and real swimming (r s = 0.369) and floating (r s = 0.583) skills were significant but only moderate in strength. No significant gender differences in real or perceived water competency were found. Significantly more males than females estimated lower risk of drowning associated with a series of aquatic scenarios (p = 0.016). The implications of these findings on drowning prevention and the need for further investigation are discussed.While the role of swimming proficiency in drowning prevention may appear axiomatic, its protective capacity is not well understood. Brenner, Saluja, and Smith (2003) have argued that increased swimming competency is almost certain to be protective in a drowning situation and, if so, then differences in swimming competency may help explain why some are at greater risk of drowning than others. The relationship between swimming competency, swimming lessons, and the risk of drowning for young children has been the subject of some inquiry (Brenner, Moran, Stallman, Gilchrist, & McVan, 2006), but little is known about this relationship with respect to young adults, one of the most at-risk groups of drowning in most developed countries.A systematic, large-scale review of childhood and youth drowning noted that even though studies have shown that swimming lessons improved the ability to dive,

Study design: To establish benchmark normative data for dive entries performed by young adults of the age range most likely to sustain a diving spinal cord injury. Data acquired from analysis of the dives performed, along with survey information, were used to determine which factors make the most contribution to the level of risk in diving. Objectives: To identify in¯uential variables which could contribute to risk of spinal cord injury for each of four types of dives. The types of dives investigated were: dive entries from deck level to tread water (Treadwater); deck level to swim 25 m (Deck); starting block height to swim 25 m (Block); and a running dive entry to swim 25 m (Running). Setting: Victoria, Australia. Methods: Ninety-®ve ®rst year university students (average age 19.9 years) performed three or four dives which were video-recorded for later analysis. Maximum depth reached was used as an indicator of risk, and velocity at maximum depth, distance at maximum depth, angle of entry and¯ight distance were measured for each dive. Participants also completed a questionnaire designed to elicit information about their swimming and diving background. Unlike previous diving studies, participants were recreational rather than competitive swimmers. They were not aware that the dive was the focal point, assuming that the researchers were investigating their swimming and treadwater ability. Results: A stepwise multiple regression was applied to predict depth for each dive condition, and demonstrated that four variables were able to account for 56% of the variance for Treadwater, 68% for Deck; 73% for Running and 79% for Block. In all conditions involving swimming after the dive (ie Deck, Block and Running), beta weights showed that distance at maximum depth had the greatest in¯uence on the depth of a dive. Flight distance and angle of entry were the next most in¯uential variables. For the Treadwater condition, beta weights showed angle of entry was the most in¯uential variable, followed by velocity at maximum depth, distance at maximum depth and swim rank. Conclusion: It is recommended that divers strive to surface in as short a distance as possible by maximising¯ight distance and aiming for a low entry angle. Implementation of steering-up techniques will assist in minimising dive depth.

This paper examines multifaceted aspects of diving entries into water which are the cause of many critical injuries (costed at $A150 million) and therefore have important safety ramifications. Wedge and compression fractures are most commonly found in the cervical area of the spine with off-centre impacts with the pool or sea bottom. Diving-related injuries range from 2.3 in a South African study to 21% of spinal cord injuries in Poland. Alcohol and diving do not mix because of diminished awareness and information processing. Children aged under 13 years suffer fewer cervical injuries (1 to 4%), but complication rates are relatively high for this group. Sports trauma (diving-related in particular) is one of the more prevalent causes of spinal cord injury in children aged 6 to 15 years. The highest incidence occurs among those aged 10 to 14, followed by the group aged 5 to 9 years. This contradicts the common perception that 15-to 19-year-olds comprise the highest risk group. Boys are more frequently injured, and swimming pools are more common as an injury location then is the case with adults. The role played by water depth has been conclusively ascertained; technique, and therefore education, appear to be more important considerations in injury prevention. Although 89% of injuries occur in water < 1.52m, injuries are rare in water of 0.46 to 0.61m. Care with pool design to avoid sudden depth changes and the resultant "spinal wall' is necessary. Minimum depth values for diving vary from 1 to 1.52 m. Velocities and angles of entry are considered to ascertain the body's decelerative capacity upon entry. The scoop, racing start dive has been shown to require at least 1.22 m of water even when practised by trained divers; the risks involved must therefore be weighed against the fact that it may be no faster than more conventional dives. While it may be safe to perform kneeling and crouching dives into shallowers water, standing dives by untrained divers require a greater margin of error. Lack of education is an issue which needs to be addressed and this paper makes recommendations for safety practices such as steering up to the surface, head protection with the arms and only diving when absolutely necessary.

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