Benjamim CJR, Monteiro LRL, Pontes YMDM, Silva AAMD, Souza TKMD, Valenti VE, Garner DM, Cavalcante TCF. Caffeine slows heart rate autonomic recovery following strength exercise in healthy subjects.
Rev Port Cardiol 2021;
40:399-406. [PMID:
34274079 DOI:
10.1016/j.repce.2020.07.021]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 07/08/2020] [Indexed: 11/28/2022] Open
Abstract
INTRODUCTION AND OBJECTIVES
Studies assessing the effects of caffeine (CAF) on the cardiovascular system have demonstrated that CAF can delay cardiac recovery following exercise. This study intended to assess the impact of CAF intake before physical exercise on heart rate variability (HRV) and cardiovascular parameters.
METHODS
This is a prospective, crossover, controlled clinical trial conducted at the University of Pernambuco, Petrolina, PE, Brazil. The experimental protocol was split into three stages with a minimum of 48 hours between them. Exercises intensity was standardized based on the one repetition maximum test (1RM), obtaining the load of each volunteer for the intensity of 75% of 1RM. In the second and third phases, the control protocols were applied and 300 mg caffeine was given 45 minutes before training. HRV indices were determined at the subsequent times: 0 to 5 minutes of rest (before) and during 30 minutes of recovery (Rec) (after exercise), divided into six intervals, each of 5 minutes.
RESULTS
The final sample involved 30 volunteers. CAF delayed HRV recovery after resistance exercise. In general, CAF impaired recovery of HRV after resistance exercise. Significant changes were observed in the RMSSD, SDNN, TINN, SD1, low frequency and high frequency indices between the control and CAF group.
CONCLUSION
CAF protocol delayed parasympathetic regulation of heart rhythm following exercise, slowing recovery of HR, blood pressure and HRV indices after exercise.
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