Physiological and cardiovascular changes associated with deep water running in the young - Possible implications for the elderly

The increased number of people taking part in deep water running (DWR) is a ttributable to the weight-independent characteristic of this form of exerci se. Deep water runners should, however, be aware of the respiratory and car diovascular repercussions that result from exercising in water. It has been well documented that water immersion (WI) alone results in decrements in r espiratory and cardiovascular parameters in young individuals immersed in w ater to the neck. These decrements become more pronounced with exercise, su ch that maximal oxygen consumption and heart rate (HR) are lower during DWR compared with running on land. Age also seems to influence these parameter s; Derion et al. found little to no change in cardiac output, stroke volume and HR during WI in older individuals compared with the decrease experienc ed in younger individuals. In contrast, gender appears to have no effect on WI or DWR response. Although differences in acute metabolic responses have been observed in num erous studies, training studies examining the effectiveness of using a DWR training programme found that DWR produced equivocal training responses whe n compared with fit and highly trained individuals running on land. Less co nvincing evidence has been provided fur untrained individuals seeking benef its from a DWR training programme, as some studies showed significant impro vements while others did not. Then is a current lack of knowledge regarding the use of this form of exercise by frail elderly individuals and/or those with osteoporosis.