Apunts Medicina de l'Esport (English Edition) Apunts Medicina de l'Esport (English Edition)
Apunts Med Esport. 2015;50:29-34 - Vol. 50 Num.185 DOI: 10.1016/j.apunts.2014.09.001

Effects of continuous and intermittent endurance exercise in autonomic balance, rating perceived exertion and blood lactate levels in healthy subjects

Hugo Cerda-Kohler a,, Yolanda Pullin b, Jorge Cancino-López c

a Escuela de Kinesiología, Facultad de Medicina, Universidad Mayor, Santiago, Chile
b Facultad de Medicina, Universidad Rafael Landivar, Ciudad de Guatemala, Guatemala
c Laboratorio de Fisiología Clínica y Función Pulmonar, Facultad de Medicina, Escuela de Kinesiología, Universidad Mayor, Santiago, Chile

Abstract

Purpose

The aim of this study was to determinate the changes in the Autonomic Balance, Rating Perceived Exertion (RPE) and blood lactate after continuous versus intermittent exercise protocols.

Methods

En el estudio participaron 7 varones activos y sanos (33 ± 5,1 años). Cada sujeto realizó 2 protocolos de ejercicios: a) un ejercicio continuo al 110% del umbral del lactato (CONT); el protocolo CONT consistió en una carrera continua, siendo la distancia cubierta en metros igual a la distancia de la sesión intermitente, y b) un ejercicio intermitente al 100% de la velocidad pico en cinta (INTT). El protocolo consistió en 30 min de carrera de 15 segundos, intercalados con 15 segundos de descanso pasivo. El balance autónomo se evaluó mediante el ratio LF/HF antes de comenzar los ejercicios, inmediatamente después de finalizar los mismos, y a las 24 h de su finalización; la RPE se evaluó cada 5 min en cada protocolo de ejercicios, y el lactato en sangre se midió inmediatamente tras ambos protocolos. El nivel alfa se estableció en p ≤ 0,05.

Seven active and healthy male (33 ± 5.1 years) participated in the study. Each subject performed two exercise protocols: (i) a continuous exercise at 110% of the lactate threshold (CONT). The CONT protocol consisted in continuous running, and the distance covered was the same in meters as it was in the intermittent session, and (ii) an intermittent exercise at 100% of the Peak Treadmill Velocity (INTT). The protocol consisted of 30 min of 15 s running, interspersed with 15 s of passive rest. Autonomic balance was assessed through the LF/HF ratio, before beginning the exercises, immediately finishing the exercises and 24 h post-exercise; RPE was evaluated every 5 min in each exercise protocol; and blood lactate was measured immediately after both protocols. Alpha level was set at P ≤ .05.

Results

Autonomic balance did not show significant differences between protocols (P = .60). RPE during INTT exercise was significantly higher than CONT exercise (P = .01). Blood lactate levels after exercise did not show significant differences (P = .68). Heart rate variability parameters in the time domain (mean RR and pNN50) show no statistical differences between both protocols pre and 24 h post exercise (P = .24 and P = .61, respectively).