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Succi PJ, Dinyer-McNeely TK, Voskuil CC, Abel MG, Clasey JL, Bergstrom HC. Responses to Exercise at the Critical Heart Rate vs. the Power Output Associated With the Critical Heart Rate. J Strength Cond Res 2023; 37:2362-2372. [PMID: 37369084 DOI: 10.1519/jsc.0000000000004547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
ABSTRACT Succi, PJ, Dinyer-McNeely, TK, Voskuil, CC, Abel, MG, Clasey, JL, and Bergstrom, HC. Responses to exercise at the critical heart rate vs. the power output associated with the critical heart rate. J Strength Cond Res 37(12): 2362-2372, 2023-This study examined the physiological (volume of oxygen consumption [V̇ o2 ], heart rate [HR], power output [PO], respiration rate [RR], muscle oxygen saturation [%SmO 2 ]), neuromuscular (electromyographic and mechanomyographic amplitude [EMG AMP and MMG AMP] and mean power frequency [EMG MPF and MMG MPF]), and perceptual (rating of perceived exertion [RPE]) responses during exercise anchored at the critical heart rate (CHR) vs. the PO associated with CHR (PCHR). Nine subjects (mean ± SD ; age = 26 ± 3 years) performed a graded exercise test and 4 constant PO trials to exhaustion at 85-100% of peak PO (PP) to derive CHR and PCHR on a cycle ergometer. Responses were recorded during trials at CHR (173 ± 9 b·min -1 , time to exhaustion [T Lim ] = 45.5 ± 20.2 minutes) and PCHR (198 ± 58 W, T Lim = 21.0 ± 17.8 minutes) and normalized to their respective values at PP in 10% intervals. There were significant ( p ≤ 0.05) mode (CHR vs. PCHR) × time (10%-100% T Lim ) interactions for all variables ( p < 0.001-0.036) except MMG AMP ( p > 0.05). Post hoc analyses indicated differences across time for CHR V̇ o2 (%change = -22 ± 16%), PCHR V̇ o2 (19 ± 5%), CHR RR (24 ± 23%), PCHR RR (45 ± 14%), CHR PO (-33 ± 11%), PCHR HR (22 ± 5%), CHR RPE (22 ± 14%), PCHR RPE (39 ± 6%), CHR %SmO 2 (41 ± 33%), PCHR %SmO 2 (-18 ± 40%), CHR EMG AMP (-13 ± 15%), PCHR EMG AMP (13 ± 13%), CHR EMG MPF (9 ± 8%), CHR MMG MPF (7 ± 11%), and PCHR MMG MPF (-3 ± 14%). The critical heart rate was more sustainable than PCHR but required adjustments in PO which traversed intensity domains and caused dissociations of the responses previously observed in exercise anchored to PO. These dissociations indicated the demands to exercise varied with anchoring scheme and provides an important consideration for practitioners prescribing endurance exercise.
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Affiliation(s)
- Pasquale J Succi
- Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, Kentucky
| | - Taylor K Dinyer-McNeely
- School of Kinesiology, Applied Health & Recreation, Oklahoma State University, Stillwater, Oklahoma; and
| | - Caleb C Voskuil
- Department of Kinesiology, Texas Christian University, Fort Worth, Texas
| | - Mark G Abel
- Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, Kentucky
| | - Jody L Clasey
- Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, Kentucky
| | - Haley C Bergstrom
- Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, Kentucky
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Mendelson BJ, Marciniak RA, Wahl CA, Ebersole KT. Body Composition Is Related to Maximal Effort Treadmill Test Time in Firefighters. Healthcare (Basel) 2023; 11:healthcare11111607. [PMID: 37297747 DOI: 10.3390/healthcare11111607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/19/2023] [Accepted: 05/29/2023] [Indexed: 06/12/2023] Open
Abstract
Firefighting tasks may require near maximal levels of cardiorespiratory fitness. Previous research has indicated that body fat percentage (BF%) and aerobic capacity (VO2peak) are related to the performance of firefighting tasks. Since a standard submaximal treadmill test for firefighters is terminated at 85% of maximal heart rate (MHR), key performance information relating to maximal cardiorespiratory effort may not be measured in a submaximal test. The purpose of this study was to examine the relationships between body composition and time spent running at intensities greater that 85% MHR. Height, weight, body mass index (BMI; kg/m2), BF%, MHR (bpm), VO2peak (mL/kg/min), predicted VO2peak (P-VO2peak; mL/kg/min), submaximal treadmill test time (WFIsub Test Time; min), and maximal treadmill test time (WFImax Test Time; min) were collected in fifteen active-duty firefighters. The results indicated that significant relationships (p < 0.05) existed between BF% and VO2peak, BF% and WFImax Test Time, BF% and Tdiff, and VO2peak and WFImax Test Time. P-VO2peak was not significantly different than VO2peak, and the WFImax Test Time was significantly longer than the WFIsub Test Time. These results indicate that a submaximal treadmill test may reasonably predict VO2peak, but key information about physiological work at intensities greater than 85% MHR may be missed when using submaximal effort tests.
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Affiliation(s)
- Benjamin J Mendelson
- Human Performance & Sport Physiology Laboratory, Department of Rehabilitation Sciences & Technology, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
| | - Rudi A Marciniak
- Human Performance & Sport Physiology Laboratory, Department of Rehabilitation Sciences & Technology, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
| | - Carly A Wahl
- Department of Kinesiology, Sport, & Recreation, Eastern Illinois University, Charleston, IL 61920, USA
| | - Kyle T Ebersole
- Human Performance & Sport Physiology Laboratory, Department of Rehabilitation Sciences & Technology, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
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Succi PJ, Dinyer TK, Byrd MT, Voskuil CC, Bergstrom HC. Application of V̇ o2 to the Critical Power Model to Derive the Critical V̇ o2. J Strength Cond Res 2022; 36:3374-3380. [PMID: 34474433 DOI: 10.1519/jsc.0000000000004134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
ABSTRACT Succi, PJ, Dinyer, TK, Byrd, MT, Voskuil, CC, and Bergstrom, HC. Application of V̇ o2 to the critical power model to derive the critical V̇ o2 . J Strength Cond Res 36(12): 3374-3380, 2022-The purposes of this study were to (a) determine whether the critical power (CP) model could be applied to V̇ o2 to estimate the critical V̇ o2 (CV̇ o2 ) and (b) to compare the CV̇ o2 with the V̇ o2 at CP (V̇ o2 CP), the ventilatory threshold (VT), respiratory compensation point (RCP), and the CV̇ o2 without the V̇ o2 slow component (CV̇ o2 slow). Nine subjects performed a graded exercise test to exhaustion to determine V̇ o2 peak, VT, and RCP. The subjects performed 4 randomized, constant power output work bouts to exhaustion. The time to exhaustion (T Lim ), the total work (W Lim ), and the total volume of oxygen consumed with (TV̇ o2 ) and without the slow component (TV̇ o2 slow) were recorded during each trial. The linear regressions of the TV̇ o2 vs. T Lim , TV̇ o2 slow vs. T Lim , and W Lim vs. T Lim relationship were performed to derive the CV̇ o2 , CV̇ o2 slow, and CP, respectively. A 1-way repeated-measures analysis of variance ( p ≤ 0.05) with follow-up Sidak-Bonferroni corrected pairwise comparisons indicated that CV̇ o2 (42.49 ± 3.22 ml·kg -1 ·min -1 ) was greater than VT (30.80 ± 4.66 ml·kg -1 ·min -1 ; p < 0.001), RCP (36.74 ± 4.49 ml·kg -1 ·min -1 ; p = 0.001), V̇ o2 CP (36.76 ± 4.31 ml·kg -1 ·min -1 ; p < 0.001), and CV̇ o2 slow (38.26 ± 2.43 ml·kg -1 ·min -1 ; p < 0.001). However, CV̇ o2 slow was not different than V̇ o2 CP ( p = 0.140) or RCP ( p = 0.235). Thus, the CP model can be applied to V̇ o2 to derive the CV̇ o2 and theoretically is the highest metabolic steady state that can be maintained for an extended period without fatigue. Furthermore, the ability of the CV̇ o2 to quantify the metabolic cost of exercise and the inefficiency associated with the V̇ o2 slow component may provide a valuable tool for researchers and coaches to examine endurance exercise.
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Affiliation(s)
- Pasquale J Succi
- Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, Kentucky
| | - Taylor K Dinyer
- Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, Kentucky
| | - M Travis Byrd
- Department of Cardiovascular Disease, Mayo Clinic, Scottsdale, Arizona
| | - Caleb C Voskuil
- Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, Kentucky
| | - Haley C Bergstrom
- Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, Kentucky
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Colucci E, Corso SD, Borges JP, Nery LE, Malaguti C. CRITICAL VS ESTIMATED HEART RATE IN ELDERLY SUBJECTS. REV BRAS MED ESPORTE 2020. [DOI: 10.1590/1517-869220202602195867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
ABSTRACT Introduction: Heart rate (HR) has been a simple and easy-to-use physiological parameter widely used to determine exercise intensity. The critical power fatigue limit model, known as the critical heart rate (CHR), can be extrapolated to HR. However, an estimate for a CHR mathematical model has not yet been extrapolated for upper limb exercise in the elderly. Objective: To compare the mathematical model previously used to estimate CHR with the heart rate values at the critical power (CP) during arm-ergometer exercises in elderly subjects. Methods: After an initial maximum-incremental exercise test on a cycle arm-ergometer, seven elderly people performed four high-intensity constant-load tests to the limit of tolerance (Tlim), to determine CP and critical heart rate (CHR). For each power output, the heart rate of the last five seconds (HRlim) and total time to exhaustion (in minutes) were obtained. The slope coefficients of the regression lines between HRlim and Tlim were defined as CHR, and between Wlim and Tlim as CP. A square-wave test was performed on a different day, in the power determined as equivalent to CP, and the heart rate at CP (CPHR) was assessed. Results: The HR-Tlim relationship was found to be hyperbolic in all subjects, who were able to sustain upper-limb exercise at CP for 20 min. CP attained 66.8±9.4% of peak work rate in the ramp test. The real average HR measured in the CP test was strikingly similar to the CHR calculated by the mathematical model of PC (137.6±16.9 versus 139.7±13.3bpm, respectively, p=0.53). There was strong correlation between the real and the estimated CHR. Conclusion: This study indicated that the maximal sustainable exercise intensity can be based on a physiological variable such as HR, and the CHR test can define exercise endurance, which can be useful in performance assessment and training prescription. Level of evidence II; Diagnostic studies – Investigating a diagnostic test.
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Bergstrom HC, Housh TJ, Cochrane KC, Jenkins NDM, Zuniga JM, Buckner SL, Goldsmith JA, Schmidt RJ, Johnson GO, Cramer JT. Factors underlying the perception of effort during constant heart rate running above and below the critical heart rate. Eur J Appl Physiol 2015; 115:2231-41. [DOI: 10.1007/s00421-015-3204-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 06/15/2015] [Indexed: 10/23/2022]
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Bergstrom HC, Housh TJ, Cochrane KC, Jenkins NDM, Buckner SL, Goldsmith JA, Zuniga JM, Schmidt RJ, Johnson GO, Cramer JT. Application of the Critical Heart Model to Treadmill Running. J Strength Cond Res 2015; 29:2237-48. [PMID: 25647653 DOI: 10.1519/jsc.0000000000000869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The mathematical model used to estimate critical power has been applied to heart rate (HR) measurements during cycle ergometry to derive a fatigue threshold called the critical heart rate (CHR). This study had 2 purposes: (a) determine if the CHR model for cycle ergometry could be applied to treadmill running and (b) examine the times to exhaustion (Tlim) and the VO2 responses during constant HR runs at the CHR. Thirteen runners (mean ± SD; age = 23 ± 3 years) performed an incremental treadmill test to exhaustion. On separate days, 4 constant velocity runs to exhaustion were performed. The total number of heart beats (HBlim) for each velocity was calculated as the product of the average 5-second HR and Tlim. The CHR was the slope coefficient of the HBlim vs. Tlim relationship. The Tlim and VO2 responses were recorded during a constant HR run at the CHR. Polynomial regression analyses were used to examine the patterns of responses for VO2 and velocity. The HBlim vs. Tlim relationship (r = 0.995-1.000) was described by the linear equation: HBlim = a + CHR (Tlim). The CHR (176 ± 7 b·min, 91 ± 3% HRpeak) was maintained for 47.84 ± 11.04 minutes. There was no change in HR but quadratic decreases in velocity and VO2. These findings indicated that the CHR model for cycle ergometry was applicable to treadmill running and represented a sustainable (30-60 minutes) intensity but cannot be used to demarcate exercise intensity domains.
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Affiliation(s)
- Haley C Bergstrom
- 1Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, Kentucky; 2Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska; and 3Department of Exercise Science, Creighton University, Omaha, Nebraska
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