Long-term aquatic training triggers positive electrical alterations and other parameters in adult female rats

ABSTRACT

The purpose of this study was to assess cardiac electrical alterations and effects on body weight, water and food consumption, and relative weight of organs of adult female rats submitted to long-term swimming training. We used adult Wistar female rats, healthy, divided into n=10 groups, groups S (sedentary) and TR (trained), which had aquatic training for sixty minutes, three times a week, for 16 weeks. We evaluated body weight (W), water and food consumption, heart rate (HR), myocardial angle (SAQRS), intervals QRS, QTc, and PR, and relative weight of adrenal glands, heart, spleen, and kidneys. For statistical analysis, we used the statistical package "SPSS version 17.0"; data distribution was verified by the Kolmogorov-Smirnov normality test. For data with parametric distribution, we used student's t test for independent samples, while for data with nonparametric distribution we applied Mann-Whitney test (p<0.05). Rats from group TR had higher water and food consumption; however, body weight was similar between groups TR and S. Group TR had electrical alterations in HR, myocardial angle (SAQRS), S and T wave, demonstrating significant bradycardia at rest and possible cardiac hypertrophy, in addition to the difference found for relative weight of spleen and kidney. Training protocol used for adult female rats favored positive electrical changes in the heart, resulting in bradycardia during rest and improvement in cardiovascular fitness.

Keywords:
Exercise; Swimming/statistics & numerical data; Heart Rate; Rats, Wistar; Adaptation