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Caffeine and physical training: effects on cardiac morphology and cardiovascular response
Roberto Ruiz1, Solange de Paula Ramos2, Marli Martins Pinge3
1Associate Postgraduate Program in Physical Education, UEM/UEL, Londrina, PR, Brazil.
Objective:
to analyze the morphological structure of cardiac, blood pressure (BP), heart rate (HR) and heart rate variability (HRV) of rats subjected to physical training with supplementation of caffeine.
Methods:
60 rats were divided into 4 groups: control (CO), control with caffeine (CAF), trained control (TRE) and trained with caffeine (TCAF). All trained groups underwent 4 weeks of swimming, and all caffeine groups were supplemented by voluntary ingestion of caffeine diluted in drinking water.
Results:
there were no changes to BP and HR between groups. Regarding HRV, there was a decrease in LFnorm (low frequency) and LF/HF ratio (low and high frequency) in TCAF and CAF compared to group (p<0.02 and p<0.03, respectively). An increase occurred in CAF compared to the CO in the component LFnorm (p<0.05). The results also showed an increase in the relative weight of heart in the TRE (p<0.04) and TCAF (p<0.03) compared to CO.
Conclusion:
caffeine did not modify the hemodynamic responses. However, physical training resulted in a decrease in sympathetic response and an increase in relative heart weight.
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