Haley C Bergstrom1, Terry J Housh2, Kristen C Cochrane2, Nathaniel D M Jenkins2, Jorge M Zuniga3, Samuel L Buckner4, Jacob A Goldsmith5, Richard J Schmidt2, Glen O Johnson2, Joel T Cramer2. 1. Department of Kinesiology and Health Promotion, University of Kentucky, 221 Seaton Building, Lexington, KY, 40506-0219, USA. hbergstrom@uky.edu. 2. Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA. 3. Department of Exercise Science, Creighton University, Omaha, NE, USA. 4. Department of Health, Exercise, and Recreation Management, University of Mississippi, Oxford, MS, USA. 5. Department of Exercise and Health Promotion, Florida Atlantic University, Boca Raton, FL, USA.
Abstract
PURPOSE: This study examined: (1) the sustainability of the critical heart rate (CHR) minus 5 b min(-1) (CHR - 5) and CHR plus 5 b min(-1) (CHR + 5); (2) the ratings of perceived exertion (RPE), velocity, [Formula: see text], minute ventilation ([Formula: see text]), breathing frequency (f b ), and electromyographic amplitude (EMG AMP) and EMG mean power frequency (MPF) responses during treadmill running at CHR - 5 and CHR + 5 to determine what factors underlie the perception of effort when heart rate (HR) is held constant; and (3) the relationships among RPE, [Formula: see text], and HR, to determine which variable(s) reflect exhaustion during exercise performed at a constant HR. METHODS: The CHR was determined in eight runners (mean ± SD; age = 24 ± 3 years) from a series of four exhaustive, constant velocity runs. The RPE, velocity, [Formula: see text], [Formula: see text], f b , EMG AMP, and EMG MPF responses were recorded during runs at the CHR - 5 and CHR + 5. RESULTS: At CHR - 5, RPE, f b, and EMG MPF increased, while velocity, [Formula: see text], [Formula: see text], and EMG AMP decreased. At CHR + 5, RPE and f b increased, velocity, [Formula: see text], [Formula: see text], and EMG AMP decreased, and EMG MPF remained constant. CONCLUSIONS: The close association between f b and RPE throughout the run at CHR - 5 and during the last 50 % of the run at CHR + 5 indicated that muscle afferents may have provided feedback from metabolic and mechanical stimuli that contributed to the perceptual responses. In addition, only RPE consistently indicated exhaustion and the current findings supported its use to monitor exercise performed at a constant HR.
PURPOSE: This study examined: (1) the sustainability of the critical heart rate (CHR) minus 5 b min(-1) (CHR - 5) and CHR plus 5 b min(-1) (CHR + 5); (2) the ratings of perceived exertion (RPE), velocity, [Formula: see text], minute ventilation ([Formula: see text]), breathing frequency (f b ), and electromyographic amplitude (EMG AMP) and EMG mean power frequency (MPF) responses during treadmill running at CHR - 5 and CHR + 5 to determine what factors underlie the perception of effort when heart rate (HR) is held constant; and (3) the relationships among RPE, [Formula: see text], and HR, to determine which variable(s) reflect exhaustion during exercise performed at a constant HR. METHODS: The CHR was determined in eight runners (mean ± SD; age = 24 ± 3 years) from a series of four exhaustive, constant velocity runs. The RPE, velocity, [Formula: see text], [Formula: see text], f b , EMG AMP, and EMG MPF responses were recorded during runs at the CHR - 5 and CHR + 5. RESULTS: At CHR - 5, RPE, f b, and EMG MPF increased, while velocity, [Formula: see text], [Formula: see text], and EMG AMP decreased. At CHR + 5, RPE and f b increased, velocity, [Formula: see text], [Formula: see text], and EMG AMP decreased, and EMG MPF remained constant. CONCLUSIONS: The close association between f b and RPE throughout the run at CHR - 5 and during the last 50 % of the run at CHR + 5 indicated that muscle afferents may have provided feedback from metabolic and mechanical stimuli that contributed to the perceptual responses. In addition, only RPE consistently indicated exhaustion and the current findings supported its use to monitor exercise performed at a constant HR.
Authors: Clayton L Camic; Terry J Housh; Glen O Johnson; C Russell Hendrix; Jorge M Zuniga; Michelle Mielke; Richard J Schmidt Journal: Eur J Appl Physiol Date: 2009-10-08 Impact factor: 3.078
Authors: K C Cochrane; T J Housh; H C Bergstrom; N D M Jenkins; G Johnson; R J Schmidt; J T Cramer Journal: Int J Sports Med Date: 2015-02-20 Impact factor: 3.118
Authors: Haley C Bergstrom; Terry J Housh; Taylor K Dinyer; Travis M Byrd; Nathaniel D M Jenkins; Kristen C Cochrane-Snyman; Pasquale J Succi; Richard J Schmidt; Glen O Johnson; Jorge M Zuniga Journal: J Musculoskelet Neuronal Interact Date: 2020-03-03 Impact factor: 2.041