RPE-lactate dissociation during extended cycling

Abstract

This study examined the association of blood lactate concentration [La] and heart rate (HR) with ratings of perceived exertion (RPE) during 60 min of steady workload cycling. Physically active college-aged subjects (n = 14) completed an exhaustive cycling test to determine VO(2) (peak) and lactate threshold (2.5 mmol l(-1)). Subjects then cycled for 60 min at the power output associated with 2.5 mmol l(-1) [LA]. HR, [LA], RPE-overall, RPE-legs and RPE-chest were recorded at 5, 10, 20, 30, 40, 50 and 60 min. The 60-min trials were below maximal lactate steady state, with peak lactate concentration occurring at 20 min after which [LA] declined. The 20-min point was therefore considered pivotal, and data at other points were compared to this time point. Repeated measures ANOVA with simple contrasts (alpha = 0.05) showed (a) [LA] at 40, 50 and 60 min was significantly lower than at 20 min, (b) RPE-O and RPE-L were significantly greater at 30, 40, 50 and 60 min than at 20 min, (c) RPE-C was significantly greater at 40, 50 and 60 min than at 20 min, and (d) HR was significantly greater at 30, 40, 50 and 60 min than at 20 min. Significant (P < 0.05) positive correlations were found between HR and RPE-O (r = 0.43), RPE-L (r = 0.48) and RPE-C (r = 0.41) while correlations for [LA]-HR (r = 0.13) and [LA]-RPE (RPE-O: r = -0.11, RPE-L: r = 0.01, RPE-C: r = -0.06) were weak and non-significant. There is a dissociation of RPE and [LA] owing to RPE drift and lactate kinetics in longer duration sub-maximal exercise. Apparently, [LA] is not a strong RPE mediator during extended cycling.

Physiologic responses of older recreational alpine skiers to different skiing modes

“…In contrast, Green et al (2005) found dissociation between LA and RPE, when 14 physically active men and women were tested during extended cycling exercise. They reported that HR and RPE responses were similar but not RPE and LA.…”

Intensidad del ejercicio en ciclismo indoor / Exercise Intensity During Indoor Cycling

“…Utilizando la escala de Borg original (25), López-Miñarro y MuyorRodriguez (3) observaron puntuaciones que indicaban una intensidad entre "duro -muy duro", similares a las puntuaciones obtenidas en nuestro estudio. Algunas variables no examinadas podrían haber afectado sobre el comportamiento de la RPE como el tipo de entrenamiento (26,27), la música (28-31) o la cadencia de pedaleo (32).…”

“…López-Miñaro y Muyor-Rodriguez (3) obtuvieron similares correlaciones entre la RPE y el %FCR (r=0.41; p<0.05) en una sesión de ciclismo indoor, al igual que otros estudios realizados sobre cicloergómetro, aunque no durante la práctica de ciclismo indoor (26,33). Las correlaciones observadas en nuestro estudio entre FC -RPE y entre %FCmáx teórica -RPE fueron similares.…”

Probing the specific ion effects of biocompatible hydrated choline ionic liquids on lactate oxidase biofunctionality in sensor applications

“…25 Consequently, there is considerable interest in lactate biosensors, but despite substantial body of research, the relatively poor stability of L-lactate oxidase (LOx) limits the effectiveness of current devices. 26,27 LOx is a flavin mononucleotide (FMN) enzyme that catalyzes the oxidation of L-lactic acid into pyruvate, producing H 2 O 2 in the process.…”