Vigorous intensity heart rate-clamp exercise does not elicit recommended oxygen consumption rates

This study examined the power output adjustments and subsequent shifts in metabolic (V̇O ) demands as well as minute ventilation ( ), respiratory rate (RR), and rating of perceived exertion (RPE) responses during vigorous intensity (77-95% HR ) heart rate (HR)-clamp cycle ergometry. Fifteen males (mean ± SD age = 25.9 ± 4.4 years) performed a graded exercise test to exhaustion to determine peak parameters and three, randomly ordered, HR-clamp trials to exhaustion, up to 60 min, at the lower (HR = 77% HR ), middle (HR = 86% HR ), and higher (HR = 95% HR ) end of the vigorous intensity range. Time course of changes were examined. The times to exhaustion (T ) for the HR , HR , and HR trials were 56.05 ± 10.09, 44.22 ± 19.00, and 9.74 ± 7.54 min, respectively. There were significant decreases in power output, , and across time for each trial, but no changes in RR, and increases in RPE (p