Autonomic, cardiovascular & physiological responses in strength training protocols

Abstract

Introduction: Strength training is a recurrent practice among several publics and the topic of several studies, yet there is a shortage of previous studies that analyzed these parameters in the same subjects in training sessions involving volume, interval and different repetitions maximum ranges. Objective: The study was aimed at measuring and comparing the acute effect of different ST (strength training) protocols on HR (heart rate), HRV (heart rate variability), [LAC] (lactate concentration), [CK] (creatine kinase) and SPE (subjective perceived exertion). Methods: Eleven individuals with previous experience were recruited and in three sessions they performed three different training models, namely: high load (4 sets at 90% of 1RM, 180s rest between sets), medium load (3 sets at 75% of 1 RM, 90s rest between sets), and low load (2 sets at 50% of 1 RM, 45s rest between sets) in free squat, bench press, deadlift and bent-over row exercises. Results: There was no difference in CK between low load (resistance) and medium load (hypertrophy) (p = 0.60), between resistance and high load (strength) (p = 0.84), and between hypertrophy and strength (p = 0.91), while there was higher lactate accumulation in training with medium and low loads in comparison to training with high loads (p <0.001). Conclusion: It can be noted that workouts with high loads, few repetitions and longer intervals (maximum strength) generate lower blood lactate concentrations and SPE values when compared to training with lower loads and shorter intervals (resistance training and hypertrophy). Additionally, when evaluating autonomic and cardiovascular variables, it would appear that manipulating the percentage of 1RM and the interval time does not generate significant changes in HRV, blood pressure (BP) and HR when the repetitions are executed until failure. Level of evidence II; Prospective comparative study.