title: A Model for Identifying Intensity Zones Above Critical Velocity.
abstract: Bergstrom, HC, Housh, TJ, Cochrane-Snyman, KC, Jenkins, NDM, Byrd, MT, Switalla, JR, Schmidt, RJ, and Johnson, GO. A model for identifying intensity zones above critical velocity. J Strength Cond Res 31(12): 3260-3265, 2017-The purpose of this study was to describe the V[Combining Dot Above]O2 responses relative to V[Combining Dot Above]O2peak at 4 different intensities within the severe domain and, based on the V[Combining Dot Above]O2 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 V[Combining Dot Above]O2peak and velocity associated with V[Combining Dot Above]O2peak (vV[Combining Dot Above]O2peak). Critical velocity was determined from 4 exhaustive, constant velocity, randomly ordered treadmill runs (V1, V2, V3, and V4; V1 = highest, V4 = lowest). The V[Combining Dot Above]O2 responses were recorded during each of the constant velocity runs. Mean differences among V[Combining Dot Above]O2peak values from the ITT and the highest value recorded during the constant velocity runs were examined. The V[Combining Dot Above]O2 values at exhaustion for V1 (3.32 ± 0.10 L·min, p = 0.15) and V2 (3.27 ± 0.91 L·min, p = 0.13) were not significantly different from V[Combining Dot Above]O2peak (3.39 ± 0.96 L·min) from the ITT. The V[Combining Dot Above]O2 values at exhaustion for V3 (3.18 ± 0.88 L·min; p = 0.007) and V4 (3.09 ± 0.86 L·min; p = 0.003), however, were significantly less than the V[Combining Dot Above]O2peak from the ITT. There were intensity-dependent V[Combining Dot Above]O2 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 V[Combining Dot Above]O2 responses and may be used to design programs that maximize aerobic performance adaptations.
authors.affiliation: Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, Kentucky.
authors.forename: Haley C
authors.initials: HC
authors.lastname: Bergstrom
authors.affiliation: Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska.
authors.forename: Terry J
authors.initials: TJ
authors.lastname: Housh
authors.affiliation: Department of Kinesiology and Health Promotion, California State Polytechnic University, Pomona, Pomona, California.
authors.forename: Kristen C
authors.initials: KC
authors.lastname: Cochrane-Snyman
authors.affiliation: Department of Health and Human Performance, Oklahoma State University, Stillwater, Oklahoma.
authors.forename: Nathaniel D M
authors.initials: NDM
authors.lastname: Jenkins
authors.affiliation: Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, Kentucky.
authors.forename: M Travis
authors.initials: MT
authors.lastname: Byrd
authors.affiliation: Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, Kentucky.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Switalla
authors.affiliation: Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schmidt
authors.affiliation: Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska.
authors.forename: Glen O
authors.initials: GO
authors.lastname: Johnson
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D005080:Exercise Test; D005221:Fatigue / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D012420:Running / Q000502:physiology*; D055815:Young Adult