The Response of Autonomous Heart System, Plasma Electrolytes and Blood Pressure to Aerobic Exercises in Different Training Conditions

The aim of this study was to investigate different effects of short-term aerobic exercises in land and water environments on blood pressure controlling mechanisms. 30 healthy young men were selected as study subjects. Then, all subjects were randomly divided into study groups (control group: mean ± SD, age 26.8 ± 1.39 years, land aerobic exercise group: 25.9 ± 1.85 years and water aerobic exercise group: 26.4 ± 1.71 years). The intervention groups participated in aerobic exercises in land and water with an intensity of approximately 70% of heart rate reserve for 3 weeks with consecutive daily sessions. All parameters of heart rate variability, plasma electrolytes and blood pressure were measured in the pretest and after exercise intervention. In order to compare differences through research stages, one-way ANOVA was used. The results showed that aerobic exercise in land environment made a significant difference in the parameters of heart rate variability (P=0.01) and insignificant difference in plasma electrolytes and blood pressure compared with the control group (P≥0.05). But, aerobic exercise in water environment showed no significant difference in heart rate variability, plasma electrolytes and blood pressure (P≥0.05). In general, it can be concluded that the aerobic exercise in land is likely to affect the blood pressure levels through the path of the nervous control. However, little control of blood pressure levels following aerobic exercise in water cannot be attributed to neural changes and plasma electrolytes, and there may be other influential factors in this regard that need further investigation.