Revista Brasileira de Medicina do Esporte
On-line version ISSN 1806-9940
OVANDO, Angélica Cristiane; EICKHOFF, Heloisa Meinke; DIAS, Jonathan Ache and WINKELMANN, Eliane Roseli. Effect of water temperature in cardiovascular responses during aquatic walking. Rev Bras Med Esporte [online]. 2009, vol.15, n.6, pp. 415-419. ISSN 1806-9940. http://dx.doi.org/10.1590/S1517-86922009000700002.
The purpose of this study was to investigate the effect of water temperature in cardiovascular responses: heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP), while walking in water at different temperatures (29°C, 33°C e 37°C). Ten men, mean age 23.2 ± 2.25 years, mean weight 78.4 ± 4.01 kg, mean stature 1.774 ± 0.017 m, participated in the study. Each individual underwent water walking in different days for each temperature during 30 min, with a controlled cadence of 55 steps per minute, at a depth in the xiphoid process. During aquatic walking, the HR and blood pressure (BP) were measured at the 5th, 10th, 20th, and 30th minute of walking. Despite the 75.4% (p<0.001) main effect of water temperature on the HR, we also identified a significant effect of 91.8% (p=0.001) of exercise time. HR increased most during exercise in water at 37°C (71.3 ± 8.4 to 114.6 ± 4.4), showing significant difference compared to 29°C (p<0.01) and 33°C (p<0.05) temperatures, which were not different from each other. Water temperature seemed to have little effect on the SBP, we have only identified differences between 29°C and 33°C temperatures in the 20' e 30' minutes (p<0.05). DBP has decreased at all temperatures studied, and it was more expressive in 37°C (70.0 ± 5.0 to 40.0 ± 2.5) showing significant difference compared to 29°C and 33°C (p<0.05) temperatures, which were not different from each other. Considering the effect of water temperature on HR and DBP during water walking, it is suggested that water temperature should be considered when walking in water, and temperatures between 29 and 33C are recommended for less cardiovascular strain during water walking.
Keywords : immersion; exercise; heart rate; blood pressure.