Cardiopulmonary, blood metabolite and rating of perceived exertion responses to constant exercises performed at different intensities until exhaustion.

Objective: This study analysed cardiopulmonary, metabolic and rating of perceived exertion (RPE) responses during exercise bouts performed below, at and above the second lactate threshold (LT2) intensity.

Methods: 10 healthy men performed constant workloads to exhaustion at the first lactate threshold (LT1), LT2 and 25% of the difference between LT2 and maximal aerobic power output (TW(25%)) identified during an incremental test. The time to exhaustion (TE) was 93.

The influence of peripheral afferent signals on the rating of perceived exertion and time to exhaustion during exercise at different intensities.

This study determined which peripheral variables would better predict the rating of perceived exertion (RPE) and time to exhaustion (TE) during exercise at different intensities. Ten men performed exercises at first lactate threshold (LT1), second lactate threshold (LT2), 50% of the distance from LT1 to LT2 (TT(50%) ), and 25% of the distance from LT2 to maximal power output (TW(25%) ). Lactate, catecholamines, potassium, pH, glucose, V(·)O₂, VE, HR, respiratory rate (RR) and RPE were measured and plotted against the exercise duration for the slope calculation.

Low carbohydrate diet affects the oxygen uptake on-kinetics and rating of perceived exertion in high intensity exercise.

The aim of this study was to determine if the carbohydrate (CHO) availability alters the rate of increase in the rating of perceived exertion (RPE) during high intensity exercise and whether this would be associated with physiological changes. Six males performed high intensity exercise after 48 h of controlled, high CHO (80%) and low CHO (10%) diets. Time to exhaustion was lower in the low compared to high CHO diet.

Ventilation behavior during upper-body incremental exercise.

This study tested the ventilation (VE) behavior during upper-body incremental exercise by mathematical models that calculate 1 or 2 thresholds and compared the thresholds identified by mathematical models with V-slope, ventilatory equivalent for oxygen uptake (VE/V(O2)), and ventilatory equivalent for carbon dioxide uptake (VE/V(CO2)). Fourteen rock climbers underwent an upper-body incremental test on a cycle ergometer with increases of approximately 20 W · min(-1) until exhaustion at a cranking frequency of approximately 90 rpm. The VE data were smoothed to 10-second averages for VE time plotting.