[130-133]. Much of the literature dealing with deep-water running with flotation belts concludes that skill levels determine maximal oxygen consumption, but that training levels can easily be achieved equal to land-based training [102,131-138]. It does need to be recognized that while aquatic cross training can present a very significant aerobic challenge to the athlete, there are differences in motor activity, muscle recruitment and cardiovascular performance .
While there are some significant differences in cardiovascular function, the overall cardiac demand appears to be at the least, equivalent [100-102] . For maintenance of cardiorespiratory conditioning in highly fit individuals, water running equals dry land running in its effect on maintenance of maximum VO2 when training intensities and frequencies are matched for training periods of up to 6 weeks, currently the longest published training studies [139-141].
Similarly, when aquatic exercise is compared with land-based equivalent exercise in effect on maximum VO2 gains in unfit individuals, aquatic exercise is seen to achieve equivalent results, and when water temperature is below thermoneutral (37°C), the gains achieved are usually accompanied by a lower heart rate .
Thus, water-based exercise programs may be used effectively to sustain or increase aerobic conditioning in athletes who need to keep weight off a joint, such as when in injury recovery or during an intensive training program in which joint or bone microtrauma is likely with exclusively land-based training. Although research has shown aquatic exercise to be at least the equivalent in aerobic training value to land-based training, a key question frequently raised is whether aquatic exercise programs have sufficient specificity to provide a reasonable training venue for athletes in this situation [100-102,143,144].
A study by Kilgore and co-workers specifically addressed the issue of running kinematics during deep water running as compared with treadmill running and found a very close comparison between the 2 when using a cross-country skiing pattern with respect to knee and ankle kinematics, whereas high-kick running styles did not match the treadmill kinematics .
A 2006 study assessed aquatic training in plyometric performance, finding comparable performance improvement to land plyometric training but with reduced post-training muscle soreness, and of course decreased joint loading .
It is unlikely that aquatic training can substantially improve dry land performance in coordination skills such as hurdles, high jump, or other complex coordination activities, where reflex timing becomes a major part of the performance success. But for many athletic activities, aquatic cross-training can sustain or even build aerobic fitness, with the side benefits of reduced joint loading, decreased muscle soreness and improved performance, and a significant potential for improved respiratory function. Programs typically used for vertical water exercise include buoyancy-assisted deep water running and cross-country skiing, aquatic treadmill running, waist-depth aqua-running, and upper extremity work using resistive devices in cool pool environments.
More on Aquatic Therapy Applications in Rehabilitation
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