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Purpose: The mediators of the perception of effort during exercise are still unclear. The aim of the present study was to examine physiological responses during runs using a rating of perceived exertion (RPE)-clamp model at the RPE corresponding to the gas exchange threshold (RPEGET) and 15% above GET (RPEGET+15%) to identify potential mediators and performance applications for RPE during treadmill running.Methods: Twenty-one runners ([Formula: see text]max = 51.7 ± 8.3 ml kg-1 min-1) performed a graded exercise test to determine maximal oxygen consumption and the RPE associated with GET and GET + 15% followed by randomized 60 min RPE-clamp runs at RPEGET and RPEGET+15%. Mean differences for [Formula: see text], heart rate (HR), minute ventilation ([Formula: see text]), respiratory frequency ([Formula: see text], respiratory exchange ratio (RER), and velocity were compared across each run.Results: After minute 14, [Formula: see text], RER and velocity did not differ across conditions, but decreased across time (p < 0.05). There was a significant (p < 0.05) condition × time interaction for [Formula: see text], where values were significantly higher during RPE-clamp runs at RPEGET+15% and decreased across time in both conditions. There were no differences across condition or time for HR, and only small difference between conditions for [Formula: see text].Conclusions: HR and [Formula: see text] may play a role in mediating the perception of effort, while [Formula: see text], RER, and [Formula: see text] may not. Although HR and [Formula: see text] may mediate the maintenance of a perceptual intensity, they may not be sensitive to differentiate perceptual intensities at GET and GET + 15%. Thus, prescribing exercise using an RPE-clamp model may only reflect a sustainable [Formula: see text] within the moderate intensity domain. [ABSTRACT FROM AUTHOR]

The purpose of this study was to describe the ... responses relative to ... peak at 4 different intensities within the severe domain and, based on the ?? responses, identify intensity zones above critical velocity (CV). Twelve runners (mean ± SD age = 23.2 ± 3.0 years) performed an incremental treadmill test (ITT) to exhaustion to determine the ... peak and velocity associated with ... peak (... peak). Critical velocity was determined from 4 exhaustive, constant velocity, randomly ordered treadmill runs (V1, V2, V3, and V4; V1 = highest, V4 = lowest). The ... responses were recorded during each of the constant velocity runs. Mean differences among ... peak values from the ITT and the highest value recorded during the constant velocity runs were examined. The ... values at exhaustion for V1 (3.32 ± 0.10 L·min-1, p = 0.15) and V2 (3.27 ± 0.91 L·min-1, p = 0.13) were not significantly different from ... peak (3.39 ± 0.96 L·min-1) from the ITT. The ... values at exhaustion for V3 (3.18 ± 0.88 L·min-1; p = 0.007) and V4 (3.09 ± 0.86 L·min-1; p = 0.003), however, were significantly less than the ... peak from the ITT. There were intensity-dependent ... responses above CV. Based on these findings, we have hypothesized 3 intensity zones (first severe intensity zone [SIZ1], second severe intensity zone [SIZ2], and extreme intensity zone [EIZ]) within the severe and extreme domains, which are characterized by specific ... responses and may be used to design programs that maximize aerobic performance adaptations. [ABSTRACT FROM AUTHOR]

The verification phase is becoming the norm for confirming V̇O2max during a graded exercise test (GXT), but the use of such testing in untrained participants in the heat remains unknown. Purpose: This study aimed to assess the V̇O2 uptake obtained during a GXT and subsequent verification phase in untrained participants in a hot environment. Methods: Twelve sedentary males completed a GXT followed by a biphasic supramaximal-load verification phase in a hot environment (39°C, 32% relative humidity). Rest between tests occurred in a temperate chamber and lasted until gastrointestinal temperature returned to baseline. Results: Mean verification phase V̇O2max (37.8 ± 4.3 mL·kg−1·min−1) was lower than GXT (39.8 ± 4.1 mL·kg−1·min−1; P = 0.03) and not statistically equivalent. Using an individualized analysis approach, only 17% (2/12) of participants achieved a V̇O2 plateau during the GXT. Verification phase confirmed GXT V̇O2max in 100% of participants, whereas the traditional and the new age-dependent secondary V̇O2max criteria indicated GXT V̇O2max achievement at much lower rates (8/12 [67%] vs 7/12 [58%], respectively). Correlational indices between GXT and verification phase V̇O2max were strong (intraclass correlation coefficient = 0.95, r = 0.86), and Bland–Altman analysis revealed a low mean bias of −2.1 ± 1.9 mL·kg−1·min−1 and 95% limits of agreement (−5.8 to 1.7 mL·kg−1·min−1). Conclusions: Very few untrained males achieved a V̇O2 plateau during GXT in the heat. When conducting GXT in a hot condition, the verification phase remains a valuable addition to confirm V̇O2max in untrained males. [ABSTRACT FROM AUTHOR]