scholarly journals Variability in Submaximal Self-Paced Exercise Bouts of Different Intensity and Duration

Author(s):  
Ciaran O’Grady ◽  
Louis Passfield ◽  
James G. Hopker

Purpose: Rating of perceived exertion (RPE) as a training-intensity prescription has been extensively used by athletes and coaches. However, individual variability in the physiological response to exercise prescribed using RPE has not been investigated. Methods: Twenty well-trained competitive cyclists (male = 18, female = 2, maximum oxygen consumption =55.07 [11.06] mL·kg−1·min−1) completed 3 exercise trials each consisting of 9 randomized self-paced exercise bouts of either 1, 4, or 8 minutes at RPEs of 9, 13, and 17. Within-athlete variability (WAV) and between-athletes variability (BAV) in power and physiological responses were calculated using the coefficient of variation. Total variability was calculated as the ratio of WAV to BAV. Results: Increased RPEs were associated with higher power, heart rate, work, volume of expired oxygen (VO2), volume of expired carbon dioxide (VCO2), minute ventilation (VE), deoxyhemoglobin (ΔHHb) (P < .001), and lower tissue saturation index (ΔTSI%) and ΔO2Hb (oxyhaemoglobin; P < .001). At an RPE of 9, shorter durations resulted in lower VO2 (P < .05) and decreased ΔTSI%, and the ΔHHb increased as the duration increased (P < .05). At an RPE of 13, shorter durations resulted in lower VO2, VE, and percentage of maximum oxygen consumption (P < .001), as well as higher power, heart rate, ΔHHb (P < .001), and ΔTSI% (P < .05). At an RPE of 17, power (P < .001) and ΔTSI% (P < .05) increased as duration decreased. As intensity and duration increased, WAV and BAV in power, work, heart rate, VO2, VCO2, and VE decreased, and WAV and BAV in near-infrared spectroscopy increased. Conclusions: Self-paced intensity prescriptions of high effort and long duration result in the greatest consistency on both a within- and between-athletes basis.

2020 ◽  
pp. 1-5
Author(s):  
Megan Wagner ◽  
Kevin D. Dames

Context: Bodyweight-supporting treadmills are popular rehabilitation tools for athletes recovering from impact-related injuries because they reduce ground reaction forces during running. However, the overall metabolic demand of a given running speed is also reduced, meaning athletes who return to competition after using such a device in rehabilitation may not be as fit as they had been prior to their injury. Objective: To explore the metabolic effects of adding incline during bodyweight-supported treadmill running. Design: Cross-sectional. Setting: Research laboratory. Participants: Fourteen apparently healthy, recreational runners (6 females and 8 males; 21 [3] y, 1.71 [0.08] m, 63.11 [6.86] kg). Interventions: The participants performed steady-state running trials on a bodyweight-supporting treadmill at 8.5 mph. The control condition was no incline and no bodyweight support. All experimental conditions were at 30% bodyweight support. The participants began the sequence of experimental conditions at 0% incline; this increased to 1%, and from there on, 2% incline increases were introduced until a 15% grade was reached. Repeated-measures analysis of variance was used to compare all bodyweight-support conditions against the control condition. Main Outcome Measures: Oxygen consumption, heart rate, and rating of perceived exertion. Results: Level running with 30% bodyweight support reduced oxygen consumption by 21.6% (P < .001) and heart rate by 12.0% (P < .001) compared with the control. Each 2% increase in incline with bodyweight support increased oxygen consumption by 6.4% and heart rate by 3.2% on average. A 7% incline elicited similar physiological measures as the unsupported, level condition. However, the perceived intensity of this incline with bodyweight support was greater than the unsupported condition (P < .001). Conclusions: Athletes can maintain training intensity while running on a bodyweight-supporting treadmill by introducing incline. Rehabilitation programs should rely on quantitative rather than qualitative data to drive exercise prescription in this modality.


2002 ◽  
Vol 95 (3_suppl) ◽  
pp. 1047-1062 ◽  
Author(s):  
Mee-Lee Leung ◽  
Pak-Kwong Chung ◽  
Raymond W. Leung

This study evaluated the validity and reliability of the Chinese-translated (Cantonese) versions of the Borg 6–20 Rating of Perceived Exertion (RPE) scale and the Children's Effort Rating Table (CERT) during continuous incremental cycle ergometry with 10- to 11-yr.-old Hong Kong school children. A total of 69 children were randomly assigned, with the restriction of groups being approximately equal, to two groups using the two scales, CERT ( n = 35) and RPE ( n = 34). Both groups performed two trials of identical incremental continuous cycling exercise (Trials 1 and 2) 1 wk. apart for the reliability test. Objective measures of exercise intensity (heart rate, absolute power output, and relative oxygen consumption) and the two subjective measures of effort were obtained during the exercise. For both groups, significant Pearson correlations were found for perceived effort ratings correlated with heart rate ( rs ≥ .69), power output ( rs ≥ .75), and oxygen consumption ( rs ≥ .69). In addition, correlations for CERT were consistently higher than those for RPE. High test-retest intraclass correlations were found for both the effort ( R = .96) and perceived exertion ( R = 89) groups, indicating that the scales were reliable. In conclusion, the CERT and RPE scales, when translated into Cantonese, are valid and reliable measures of exercise intensity during controlled exercise by children. The Effort rating may be better than the Perceived Exertion scale as a measure of perceived exertion that can be more validly and reliably used with Hong Kong children.


2008 ◽  
Vol 16 (1) ◽  
pp. 14-23 ◽  
Author(s):  
David R. Dolbow ◽  
Richard S. Farley ◽  
Jwa K. Kim ◽  
Jennifer L. Caputo

The purpose of this study was to examine the cardiovascular responses to water treadmill walking at 2.0 mph (3.2 km/hr), 2.5 mph (4.0 km/hr), and 3.0 mph (4.8 km/hr) in older adults. Responses to water treadmill walking in 92 °F (33 °C) water were compared with responses to land treadmill walking at 70 °F (21 °C) ambient temperature. After an accommodation period, participants performed 5-min bouts of walking at each speed on 2 occasions. Oxygen consumption (VO2), heart rate (HR), systolic blood pressure (SBP), and rating of perceived exertion (RPE) were significantly higher during therapeutic water treadmill walking than during land treadmill walking. Furthermore, VO2, HR, and RPE measures significantly increased with each speed increase during both land and water treadmill walking. SBP significantly increased with each speed during water treadmill walking but not land treadmill walking. Thus, it is imperative to monitor HR and blood pressure for safety during this mode of activity for older adults.


2020 ◽  
Vol 5 (1) ◽  
pp. 15 ◽  
Author(s):  
Andrea Fusco ◽  
William Sustercich ◽  
Keegan Edgerton ◽  
Cristina Cortis ◽  
Salvador J. Jaime ◽  
...  

Rating of perceived exertion (RPE) and session RPE (sRPE) are reliable tools for predicting exercise intensity and are alternatives to more technological and physiological measurements, such as blood lactate (HLa) concentration, oxygen consumption and heart rate (HR). As sRPE may also convey some insights into accumulated fatigue, the purpose of this study was to examine the effects of progressive fatigue in response to heavier-than-normal training on sRPE, with absolute training intensity held constant, and determine its validity as marker of fatigue. Twelve young adults performed eight interval workouts over a two-week period. The percentage of maximal HR (%HRmax), HLa, RPE and sRPE were measured for each session. The HLa/RPE ratio was calculated as an index of fatigue. Multilevel regression analysis showed significant differences for %HRmax (p = 0.004), HLa concentration (p = 0.0001), RPE (p < 0.0001), HLa/RPE ratio (p = 0.0002) and sRPE (p < 0.0001) across sessions. Non-linear regression analysis revealed a very large negative relationship between HLa/RPE ratio and sRPE (r = −0.70, p < 0.0001). These results support the hypothesis that sRPE is a sensitive tool that provides information on accumulated fatigue, in addition to training intensity. Exercise scientists without access to HLa measurements may now be able to gain insights into accumulated fatigue during periods of increased training by using sRPE.


1999 ◽  
Vol 9 (4) ◽  
pp. 434-442 ◽  
Author(s):  
Samuel N. Cheuvront ◽  
Robert J. Moffatt ◽  
Kyle D. Biggerstaff ◽  
Shawn Bearden ◽  
Paul McDonough

Claims that ENDUROX™ enhances performance by altering metabolic responses to exercise were tested. In a double-blind crossover design, 10 male subjects were randomly assigned to consume 400 mg of placebo or 800 mg ENDUROX™ for 7 days. Cycle ergometry was performed for 30 minutes at 25%, followed by 10 min at 65% of peak oxygen consumption. After a 1-week washout period, subjects performed the identical exercise protocol following 7 days of reciprocal supplemental conditions. Expired gases were collected and analyzed continuously for oxygen consumption, minute ventilation, and respiratory exchange ratio. Heart rate, blood pressure, rating of perceived exertion, blood lactate, and serum glycerol data were also collected at regular intervals. A two-way ANOVA with repeated measures revealed no significant main or interaction effects involving group differences (p > 0.05) between trials for any variable during rest, 25% or 65% (VO2 peak), or recovery. Our findings do not support the ergogenic claims for ENDUROX™.


EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
PG Green ◽  
D Holdsworth ◽  
C Monteiro ◽  
T Betts ◽  
N Herring

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): British Heart Foundation (BHF) and Local Departmental Research Funding Background Fusion pacing as part of cardiac resynchronization therapy (CRT) requires correct timing of left ventricular pacing to right ventricular activation.  The SyncAV algorithm, available in Quadra Allure and Assura CRT devices, is designed to allow optimal fusion pacing by dynamic reassessment of intrinsic atrio-ventricular (AV) conduction to adjust the paced/sensed AV delay. However, it is unclear whether AV optimisation continues to maintain resynchronisation during exercise, or whether potential loss of fusion pacing with changes in intrinsic AV conduction could lead to decreased exercise capacity. Cardio-pulmonary exercise testing (CPET) is the gold standard method for assessing exercise performance. Purpose To assess exercise capacity using the SyncAV algorithm for fusion pacing, compared with conventional biventricular pacing with fixed AV delays (AVD) for CRT. Methods  Patients at least 6 months post-CRT implant were recruited in a prospective single-centre randomized single-blind crossover study.  Patients performed 2 CPET tests at least 1 week apart, with randomization to either SyncAV with fusion pacing or conventional biventricular pacing with a fixed AVD of 120ms. All other programming was optimised to produce the narrowest QRS duration possible at rest in each case. Results Nine patients (5 male, age 70 ± 10 years, mean ± standard deviation) were recruited, with both ischaemic and non-ischaemic aetiology of heart failure.  All had clinical or echocardiographic response to CRT.  There was no difference in peak oxygen consumption (V̇O2max) between programming (1.47 ± 0.57 vs 1.50 ± 0.65 l/min for fixed AVD and SyncAV groups respectively, p = 0.59), or oxygen consumption at anaerobic threshold (VT1) (0.72 ± 0.20 vs 0.74 ± 0.25 l/min, p = 0.57). There was no difference in oxygen pulse (V̇O2/heart rate - a surrogate of stroke volume) at peak (12.3 ± 3.8 vs 13 ± 5.0 ml/beat , p = 0.28) or VT1 (8.4 ± 2.2 vs 8.7 ± 2.1 ml/beat, p = 0.67) and also no change in time to V̇O2max (1400 ± 491 vs 1367 ± 543 seconds, p = 0.38) or VT1 (518 ± 211 vs 534 ± 200 seconds, p = 0.75).  Average heart rate at the median stage of exercise showed no difference between programming (96 ± 18 vs 93 ± 15 bpm respectively, p = 0.32).  There was no difference in BORG Rating of Perceived Exertion (BORG-RPE) score at either peak exercise (median 19 [interquartile range (IQR) 2] vs 17 [IQR 2], p = 0.23) or at the median stage of exercise (median 13 [IQR 1] vs 13 [IQR 2], p = 0.30).  Conclusion Fusion pacing using the SyncAV algorithm does not appear to improve exercise capacity compared to optimised conventional biventricular pacing with fixed AVD.


Author(s):  
Jennifer N. Ahrens ◽  
Lisa K. Lloyd ◽  
Sylvia H. Crixell ◽  
John L. Walker

People of all ages and fitness levels participate regularly in aerobic-dance bench stepping (ADBS) to increase fitness and control body weight. Any reasonable method for enhancing the experience or effectiveness of ADBS would be beneficial. This study examined the acute effects of a single dose of caffeine on physiological responses during ADBS in women. When compared with a placebo, neither a 3- nor a 6-mg/kg dose of caffeine altered physiological responses or rating of perceived exertion (RPE) in 20 women (age 19–28 y) of average fitness level, not habituated to caffeine, while they performed an ADBS routine. Since neither dose of caffeine had any effect on VO2, Vco2, minute ventilation, respiratory-exchange ratio, rate of energy expenditure, heart rate, or RPE during ADBS exercise, it would not be prudent for a group exercise leader to recommend caffeine to increase energy cost or decrease perception of effort in an ADBS session. Furthermore, caffeine ingestion should not interfere with monitoring intensity using heart rate or RPE during ADBS.


2018 ◽  
Vol 13 (9) ◽  
pp. 1215-1222 ◽  
Author(s):  
Theo Ouvrard ◽  
Alain Groslambert ◽  
Gilles Ravier ◽  
Sidney Grosprêtre ◽  
Philippe Gimenez ◽  
...  

Purpose: To identify the impact of a leading teammate in front of a cyclist on psychological, physiological, biomechanical, and performance parameters during an uphill maximal effort. Methods: After familiarization, 12 well-trained competitive cyclists completed 2 uphill time trials (UTTs, 2.7 km at 7.4%) in randomized order; that is, 1 performed alone (control condition) and 1 followed a simulated teammate during the entire UTT (leader condition). Performance (UTT time) and mean power output (PO) were recorded for each UTT. For physiological parameters, mean heart rate and postexercise blood lactate concentration were recorded. Psychological parameters (rating of perceived exertion, pleasure, and attentional focus) were collected at the end of each trial. Results: Performance (UTT time) significantly improved by 4.2% (3.1%) in the leader condition, mainly due to drafting decrease of the aerodynamic drag (58% of total performance gains) and higher end spurt (+9.1% [9.1%] of mean PO in the last 10% of the UTT). However, heart rate and postexercise blood lactate concentration were not significantly different between conditions. From a psychological aspect, higher pleasure was observed in the leader condition (+41.1% [51.7%]), but attentional focus was not significantly different. Conclusions: The presence of a leading teammate during uphill cycling had a strong impact on performance, enabling higher speed for the same mean PO and greater end spurt. These results explain why the best teams competing for the general classification of the most prestigious and contested races like the Grand Tours tend to always protect their leader with teammates during decisive ascents.


Author(s):  
Stacey P A Forbes ◽  
Lawrence L. Spriet

This study examined if acute dietary nitrate supplementation (140 ml beetroot juice, BRJ) would reduce oxygen consumption (V̇O2) during cycling at power outputs of 50 and 70% V̇O2max in 14 well-trained female Canadian University Ringette League athletes. BRJ had no effect on VO2 or heart rate but significantly reduced ratings of perceived exertion (RPE) at both intensities. Individually, 4 participants responded to BRJ supplementation with a ≥3% reduction in V̇O2 at the higher power output. • Acute BRJ supplementation did not improve exercise economy in well-trained females, but significantly reduced RPE. However, 4/14 subjects did respond with a ≥3% V̇O2 reduction.


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