Physiological responses to maximal treadmill and deep water running in the young and the middle aged males.

In this study we investigated the effects of age factors on physiological responses to deep water running (DWR) compared with those of treadmill running (TMR) while the water and ambient temperatures were kept in thermoneutral conditions. Fourteen young healthy non-smoker males (Age = 20.4 +/- 3.3 years, Height = 170.7 +/- 6.2 cm, Weight = 65.1 +/- 11.4 kg) and fourteen middle aged healthy non-smoker males (Age = 38.6 +/- 4.4 years, Height = 171.8 +/- 4.7 cm, Weight = 75.4 +/- 9.6 kg) were selected for the study. Two maximal tests, one on the treadmill and the other running in deep water using the Wet Vest (Lincoln life jacket) were completed by each subject. The order of trial was counterbalanced with half of the subjects in each group completing TMR first and the rest of those completing DWR first. Although the young males had significantly (P < 0.05) higher relative VO2max, HRmax than the middle aged males, there were no significant differences in absolute VO2max, respiratory exchange ratio (RER), maximal ventilation (VEmax), ratings of perceived exhaustion (RPE), and peak blood lactate values between the two groups. In conclusion, the VO2max, HRmax, VEmax, and peak blood lactate value in response to DWR were significantly lower than those to TMR in both the young and the middle aged males in the thermoneutral conditions. However, there was no significant interaction between age and exercise modes other than RPE of legs at maximal efforts in the present study. We found that the decrease in the maximal physiological responses to DWR compared to TMR is not different between the young and middle aged males.