scholarly journals Potential Effect of Beetroot Juice Supplementation on Exercise Economy in Well-Trained Females

2021 ◽  
Author(s):  
Stacey P A Forbes ◽  
Lawrence L. Spriet
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Perceived Exertion ◽  
Potential Effect ◽  
Beetroot Juice ◽  
Ratings Of Perceived Exertion ◽  
Exercise Economy ◽  
Higher Power ◽  
Nitrate Supplementation ◽  
Power Outputs

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.

scholarly journals Optic Flow Influences Perceived Exertion During Cycling

2012 ◽  
Vol 34 (4) ◽  
pp. 444-456 ◽  
Author(s):  
David Parry ◽  
Camilla Chinnasamy ◽  
Dominic Micklewright
Keyword(s):  
Heart Rate ◽  
Power Output ◽  
Optic Flow ◽  
Perceived Exertion ◽  
Ratings Of Perceived Exertion ◽  
Video Footage ◽  
Higher Power ◽  
Cycling Time

Optic flow on the retina creates a perception of a person’s movement relative to their surroundings. This study investigated the effect of optic flow on perceived exertion during cycling. Fifteen participants completed a 20-km reference cycling time trail in the fastest possible time followed by three randomly counterbalanced 20-km cycling trials. Optic flow, via projected video footage of a cycling course, either represented actual speed (TTNORM) or was varied by −15% (TTSLOW) and +15% (TTFAST). During TTSLOW, power output and ratings of perceived exertion (RPE), measured every 4 km, were lower during TTSLOW compared with TTNORM and TTFAST. There were no differences in heart rate or cadence. This study is the first to show that different rates of optic flow influence perceived exertion during cycling, with slower optic flow being associated with lower RPE and higher power output.

scholarly journals ACUTE DIETARY NITRATE SUPPLEMENTATION FAILS TO IMPROVE EXERCISE ECONOMY IN ELDERLY

2017 ◽  
pp. 1-4
Author(s):  
M. Driller ◽  
L. Thompson ◽  
J. McQuillan ◽  
R. Masters
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Perceived Exertion ◽  
Double Blind ◽  
Walking Test ◽  
Dietary Nitrate ◽  
Exercise Economy ◽  
Nitrate Supplementation ◽  
Walking Economy ◽  
Experimental Trials

Objective: Improvements in exercise economy following dietary nitrate (NO3-) supplementation in young, athletic populations has been well documented, but little research has focused on whether these same benefits translate to elderly populations. Design: Participants completed two experimental trials in a double-blind, randomized, crossover design. Setting: University laboratory. Participants: Twenty-one elderly participants >65 yr (10 male/11 female, mean ± SD; age: 72 ± 6 yr). Intervention: Each trial consisted of participants ingesting a 70ml dose of either NO3- rich (NIT; 5.0mmol.L-1) or NO3- depleted (PLA; 0.003mmol.L-1) beetroot juice two hours prior to reporting to the laboratory. Measurements: On arrival at the laboratory, blood pressure was assessed followed by a five minute walking economy test on a treadmill (3km.h-1 and 1% gradient). VO2, heart rate and RPE were monitored during the walking test. Results: There were no significant differences (p > 0.05) between NIT and PLA trials for any of the measured variables during the walking test. Furthermore, no differences were found for blood pressure between trials. All results were associated with trivial or unclear effect sizes. Conclusion: Despite recent reports of improved exercise economy in young, athletic populations following NO3- supplementation, the current study did not find any benefit to sub-maximal VO2, heart rate, perceived exertion or blood pressure in elderly participants when performing a 5-minute walk following NO3- supplementation.

scholarly journals Caffeine effects on velocity selection and physiological responses during RPE production

2016 ◽  
Vol 41 (10) ◽  
pp. 1077-1082 ◽  
Author(s):  
James M. Green ◽  
Alyssa Olenick ◽  
Caroline Eastep ◽  
Lee Winchester
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Statistical Significance ◽  
Maximal Oxygen Consumption ◽  
Ratings Of Perceived Exertion ◽  
Caffeine Ingestion ◽  
Recreational Runners ◽  
Velocity Selection

Caffeine (CAF) blunts estimated ratings of perceived exertion (RPE) but the effects on RPE production are unclear. This study examined effects of acute caffeine ingestion during treadmill exercise where participants exercised at prescribed RPE 4 and 7. Recreational runners (maximal oxygen consumption = 51.4 ± 9.8 mL·kg−1·min−1) (n = 16) completed a maximal treadmill test followed by trials where they selected treadmill velocity (VEL) (1% grade) to produce RPE 4 and RPE 7 (10 min each). RPE production trials followed CAF (6 mg·kg−1) or placebo (PLA) (counterbalanced) ingestion. Participants were blinded to treadmill VEL but the Omni RPE scale was in full view. Repeated-measures ANOVA showed a main effect (trial) for VEL (CAF ∼5 m·min−1 faster) for RPE 4 (p = 0.07) and RPE 7 (p = 0.03). Mean heart rate and oxygen consumption responses were consistently higher for CAF but failed to reach statistical significance. Individual responses to CAF were labeled positive using a criterion of 13.4 m·min−1 faster for CAF (vs. PLA). Ten of 32 trials (31%) were positive responses. In these, systematic increases were observed for heart rate (∼12 beats·min−1) and oxygen consumption (∼5.7 mL·kg−1·min−1). Blunted/stable respiratory exchange ratio values at higher VEL for positive responders suggest increased free fatty acid reliance during CAF. In conlusion, mean results show a mild effect of CAF during RPE production. However, individual responses more clearly indicate whether a true effect is possible. Trainers and individuals should consider individual responses to ensure effectively intensity regulation.

scholarly journals Cardiorespiratory function associated with dietary nitrate supplementation

2014 ◽  
Vol 39 (2) ◽  
pp. 168-172 ◽  
Author(s):  
Vernon Bond ◽  
Bryan H. Curry ◽  
Richard G. Adams ◽  
Richard M. Millis ◽  
Georges E. Haddad
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Aerobic Exercise ◽  
Minute Ventilation ◽  
Peak Oxygen Consumption ◽  
Beetroot Juice ◽  
Dietary Nitrate ◽  
Cardiorespiratory Function ◽  
Ergometer Exercise ◽  
Nitrate Supplementation

The advent of medical nutrition therapy and nutritional physiology affords the opportunity to link diet to specific cardiovascular mechanisms, suggesting novel treatments for cardiovascular disease. This study tests the hypothesis that beetroot juice increases the plasma nitric oxide (NO) concentration, which is associated with improvements in cardiorespiratory function at rest and during submaximal aerobic exercise. The subjects were 12 healthy, young adult, normotensive African-American females, with a body mass of 61 ± 2 kg, body fat of 28% ± 4%, and peak oxygen consumption of 26 ± 3 mL·kg−1·min−1. The subjects were studied at rest and during cycle ergometer exercise at 40%, 60%, and 80% of peak oxygen consumption. Plasma NO concentration, respiratory quotient (RQ), minute ventilation, systolic and diastolic blood pressure (SBP and DBP), heart rate, and oxygen consumption were compared between isocaloric, isovolumetric placebo control orange juice and experimental beetroot juice treatments on separate days. The beetroot juice treatment increased plasma NO concentration and decreased oxygen consumption, SBP, and the heart rate-SBP product at rest and at 40%, 60%, and 80% of peak oxygen consumption in the absence of significant effects on RQ, minute ventilation, heart rate, and DBP. These findings suggest that, in healthy subjects, beetroot juice treatments increase plasma NO concentration and decrease cardiac afterload and myocardial oxygen demand at rest and during 3 submaximal levels of aerobic exercise. Future studies should determine the cellular and molecular mechanisms responsible for the improvement in cardiorespiratory function associated with dietary nitrate supplementation and whether they translate into better cardiovascular function and exercise tolerance in individuals with a compromised cardiovascular system.

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

2021 ◽  
pp. 1-10
Author(s):  
Ciaran O’Grady ◽  
Louis Passfield ◽  
James G. Hopker
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Perceived Exertion ◽  
Near Infrared ◽  
Minute Ventilation ◽  
Saturation Index ◽  
Rating Of Perceived Exertion ◽  
Maximum Oxygen Consumption ◽  
Higher Power ◽  
Competitive Cyclists

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.

Omni Scale Rating of Perceived Exertion at Ventilatory Breakpoint by Direct Observation of Children's Kinematics

2007 ◽  
Vol 104 (3) ◽  
pp. 975-984 ◽  
Author(s):  
Robert J. Robertson ◽  
Fredric L. Goss ◽  
Deborah J. Aaron ◽  
A. C. Utter ◽  
E. Nagle
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Perceived Exertion ◽  
Treadmill Exercise ◽  
Rating Of Perceived Exertion ◽  
Ratings Of Perceived Exertion ◽  
Trained Observer ◽  
Self Rating ◽  
Code Group ◽  
Omni Scale

Direct kinematic observation was used to measure ratings of perceived exertion at the ventilatory breakpoint (RPE-Vpt) in 10- to 14-yr.-old girls ( n = 22) and boys ( n = 22). RPE for the overall body, legs, and chest were simultaneously estimated by a trained observer and self-rated by a subject during treadmill exercise using the Children's OMNI-Walk/Run Scale. Subjects' heart rate and oxygen consumption were measured during each minute of exercise. Vpt for the girls and boys, respectively, were 64.2 and 66.5% VO2 max. RPE-Vpt ranged from 6.0 to 6.5 Overall, 7.1 to 7.6 Legs, and 5.0 to 5.5 Chest for both the observation and self-rating procedures. Responses indicated (a) RPE-Vpt (Overall, Legs, Chest) did not differ ( p>.05) between the observer and self-rating procedures and (b) Observer RPE-Vpt-Legs was greater ( p<.05) than RPE-Vpt-Chest. Findings validated direct kinematic observation to code group-normalized RPE-Vpt for girls and boys performing treadmill exercise.

Difference in Pacing Between Time- and Distance-Based Time Trials in Trained Cyclists

2016 ◽  
Vol 11 (8) ◽  
pp. 1018-1023 ◽  
Author(s):  
Chris R. Abbiss ◽  
Kevin G. Thompson ◽  
Marcin Lipski ◽  
Tim Meyer ◽  
Sabrina Skorski
Keyword(s):  
Power Output ◽  
Perceived Exertion ◽  
Average Power ◽  
Ratings Of Perceived Exertion ◽  
Similar Time ◽  
Long Duration ◽  
Higher Power ◽  
Average Power Output ◽  
Rate Of Decline ◽  
Power Outputs

The purpose of this study was to compare the pacing profiles between distance- and duration-based trials of short and long duration. Thirteen trained cyclists completed 2 time-based (6 and 30 min) and 2 distance-based (4 and 20 km) self-paced cycling time trials. Participants were instructed to complete each trial with the highest average power output. Ratings of perceived exertion (RPEs) were measured throughout the trials. Average power output was not different between the 4-km and 6-min trials (324 ± 46 vs 325 ± 45 W; P = .96) or between the 20-km and 30-min trials (271 ± 44 vs 267 ± 38 W; P = .24). Power output was greater on commencement of the distance-based trials when short and long trials were analyzed together. Furthermore, the rate of decline in power output over the 1st 40% of the trial was greater in the 20-km trial than in the 30-min trial (P = .01) but not different between the 4-km and the 6-min trials (P = .13). RPE was greater in the 4-km trial than in the 6-min trial but not different between the 20-km and 30-min trials. These findings indicate that athletes commenced distance-based time trials at relatively higher power outputs than a similar time-based trial. Such findings may result from discrete differences in our ability to judge or predict an exercise endpoint when performing time- and distance-based trials.

Psychophysical and physiological comparison of squat and semi-squat lifting by young males

1999 ◽  
Vol 2 (1) ◽  
pp. 17-26
Author(s):  
Leon Straker ◽  
Carol Cain
Keyword(s):  
Heart Rate ◽  
Perceived Exertion ◽  
Ratings Of Perceived Exertion ◽  
Lower Heart Rate ◽  
Young Males ◽  
Squat Lifting

A comparison between semi-squat and squat techniques was made for floor to knuckle height lifting using maximum acceptable weight (MAW), ratings of perceived exertion (RPE) and heart rate. Semi-squat lifting resulted in greater MAW with lower RPE and lower heart rate compared to squat lifting. Discomfort was most commonly reported in knees/quadriceps with squat lifting. Twelve of the 13 subjects preferred the semi-squat technique. The results provide evidence that the semi-squat technique may have benefits over the squat technique for lifting a medium sized box from floor to knuckle height.

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