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

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.

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.


1998 ◽  
Vol 23 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Dixie L. Thompson ◽  
Keith A. West

A paucity of data exists related to the usefulness of Ratings of Perceived Exertion (RPE) to set exercise intensity in non-laboratory settings. The purpose of this study was to determine if RPE could be used on an outdoor track to generate blood lactate and heart rate (HR) responses similar to those obtained on a treadmill (tm) run. Nine experienced runners (6 males, 3 females; [Formula: see text]) completed a horizontal, incremental tm test. HR, RPE, and lactate were measured for each stage. Subsequently, subjects ran for 30 min on an outdoor track at the RPE corresponding with 2.5 mM lactate during the tm run. Repeated measures ANOVA compared lactate and HR values at 2.5 mM lactate on the tm run and values obtained during the track run. Lactate during the track run was significantly higher (p < .05) than 2.5 mM throughout the 30 min (6.9 ± 2.9, 63 ± 2.9, and 5.8 ± 3.0 mM at 10, 20, and 30 min, respectively). HR at 2.5 mM lactate during the tm run (173 ± 6.1 bpm) was significantly lower (p < .05) than at min 10 and 20 of the track run (182.6 ± 9.3 and 182.9 ± 8.0 bpm, respectively) but not different from min 30 (181.3 ± 10.6 bpm). In summary, it is difficult to generate specific physiological responses using RPE. Key words: RPE, Borg Scale, exercise, lactate, training


2017 ◽  
Vol 12 (3) ◽  
pp. 295-303 ◽  
Author(s):  
Moritz Schumann ◽  
Javier Botella ◽  
Laura Karavirta ◽  
Keijo Häkkinen

Purpose:To compare the effects of a standardized endurance-training program with individualized endurance training modified based on the cumulative training load provided by the Polar training-load feature.Methods:After 12 wk of similar training, 24 recreationally endurance-trained men were matched to a training-load-guided (TL, n = 10) or standardized (ST, n = 14) group and continued training for 12 wk. In TL, training sessions were individually chosen daily based on an estimated cumulative training load, whereas in ST the training was standardized with 4–6 sessions/wk. Endurance performance (shortest 1000-m running time during an incremental field test of 6 × 1000 m) and heart-rate variability (HRV) were measured every 4 wk, and maximal oxygen consumption (VO2max) was measured during an incremental treadmill test every 12 wk.Results:During weeks 1–12, similar changes in VO2max and 1000-m time were observed in TL (+7% ± 4%, P = .004 and –6% ± 4%, P = .069) and ST (+5% ± 7%, P = .019 and –8% ± 5%, P < .001). During wk 13–24, VO2max statistically increased in ST only (3% ± 4%, P = .034). The 1000-m time decreased in TL during wk 13–24 (–9% ± 5%, P = .011), but in ST only during wk 13–20 (–3% ± 2%, P = .003). The overall changes in VO2max and 1000-m time during wk 0–24 were similar in TL (+7% ± 4%, P = .001 and –9% ± 5%, P = .011) and ST (+10% ± 7%, P < .001 and –13% ± 5%, P < .001). No between-groups differences in total training volume and frequency were observed. HRV remained statistically unaltered in both groups.Conclusions:The main finding was that training performed according to the cumulative training load led to improvements in endurance performance similar to those with standardized endurance training in recreational endurance runners.


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.


2020 ◽  
Vol 15 (6) ◽  
pp. 853-861
Author(s):  
Claire A. Molinari ◽  
Florent Palacin ◽  
Luc Poinsard ◽  
Véronique L. Billat

Purpose: To validate a new perceptually regulated, self-paced maximal oxygen consumption field test (the Running Advisor Billat Training [RABIT] test) that can be used by recreational runners to define personalized training zones. Design: In a cross-sectional study, male and female recreational runners (N = 12; mean [SD] age = 43 [8] y) completed 3 maximal exercise tests (2 RABIT tests and a University of Montreal Track Test), with a 48-hour interval between tests. Methods: The University of Montreal Track Test was a continuous, incremental track test with a 0.5-km·h−1 increment every minute until exhaustion. The RABIT tests were conducted at intensities of 11, 14, and 17 on the rating of perceived exertion (RPE) scale for 10, 5, and 3 minutes, respectively, with a 1-minute rest between efforts. Results: The 2 RABIT tests and the University of Montreal Track Test gave similar mean (SD) maximal oxygen consumption values (53.9 [6.4], 56.4 [9.1], and 55.4 [7.6] mL·kg−1·min−1, respectively, P = .722). The cardiorespiratory and speed responses were reliable as a function of the running intensity (RPE: 11, 14, and 17) and the relative time point for each RPE stage. Indeed, the oxygen consumption, heart rate, ventilation, and speed values did not differ significantly when the running time was expressed as a relative duration of 30%, 60%, or 90% (ie, at 3, 6, and 9 min of a 10-min effort at RPE 11; P = .997). Conclusions: The results demonstrate that the RABIT test is a valid method for defining submaximal and maximal training zones in recreational runners.


1998 ◽  
Vol 86 (3_suppl) ◽  
pp. 1153-1154 ◽  
Author(s):  
Thomas J. Pujol ◽  
Mark E. Langenfeld ◽  
Jeramie R. Hinojosa ◽  
Willard H. Iman

17 college-age subjects performed two 20-min. runs at 65% of maximal oxygen consumption. Randomized trials were conducted with an external nasal dilator strip or without. Subjects were polled every 5 min. for over-all rating of perceived exertion, central rating of perceived exertion, and local rating of perceived exertion. The use of an external nasal dilator strip did not significantly lower any of the three.


2016 ◽  
Vol 11 (8) ◽  
pp. 1094-1099 ◽  
Author(s):  
Katrina Taylor ◽  
Jeffrey Seegmiller ◽  
Chantal A. Vella

Purpose:To determine whether a decremental protocol could elicit a higher maximal oxygen consumption (VO2max) than an incremental protocol in trained participants. A secondary aim was to examine whether cardiac-output (Q) and stroke-volume (SV) responses differed between decremental and incremental protocols in this sample. Methods:Nineteen runners/triathletes were randomized to either the decremental or incremental group. All participants completed an initial incremental VO2max test on a treadmill, followed by a verification phase. The incremental group completed 2 further incremental tests. The decremental group completed a second VO2max test using the decremental protocol, based on their verification phase. The decremental group then completed a final incremental test. During each test, VO2, ventilation, and heart rate were measured, and cardiac variables were estimated with thoracic bioimpedance. Repeated-measures analysis of variance was conducted with an alpha level set at .05. Results:There were no significant main effects for group (P = .37) or interaction (P = .10) over time (P = .45). VO2max was similar between the incremental (57.29 ± 8.94 mL · kg–1 · min–1) and decremental (60.82 ± 8.49 mL · kg–1 · min–1) groups over time. Furthermore, Q and SV were similar between the incremental (Q 22.72 ± 5.85 L/min, SV 119.64 ± 33.02 mL/beat) and decremental groups (Q 20.36 ± 4.59 L/min, SV 109.03 ± 24.27 mL/beat) across all 3 trials. Conclusions:The findings suggest that the decremental protocol does not elicit higher VO2max than an incremental protocol but may be used as an alternative protocol to measure VO2max in runners and triathletes.


2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Honggang Yin

Objective  Heart rate variability (HRV) is a non-invasive clinical indicator of cardiovascular health, to date there has been little agreement on what HRV recovery following exercise. The present study aimed to evaluate the acute effects of cardio pulmonary exercise test (CPET) on cardiac autonomic activity in adolescent individuals. Methods Fifty-two healthy participants (Male=26, age: 20.31±1.49 years, height: 176±5.67 cm, body mass: 69.08±10.27 kg. Female=26, age: 20.62±0.98 years, height: 162.46±5.39 cm, body mass: 53.42±7.31 kg) underwent CEPT measurements of HRmax and VO2peak. Tests were performed on the Master Screen CPX model according to the Bruce protocol (JAEGER, Germany). Predicted peak heart rate was calculated as 220-age. HRV measurements were collected using the SphygmoCor device (AtCor Medical, Australia) at baseline, 5, 30 and 60 min after the CPET. Differences between groups were assessed using an independent t-test. The HRV variables were analyzed using a 2-factor [sex (male, female); time (Baseline, Post-5min, Post-30min, Post-60min)] repeated-measures ANOVA. Results  There were significant differences in VO2peak (51.09±4.41 vs. 37.59±3.62 ml min-1 kg-1) (P<0.05), RPE (ratings of perceived exertion)、RER (respiratory exchange ratio) were similar between groups (P>0.05). There were significant increases (P<0.01) in heart rate, markers of sympathetic activity (nLF) and sympathovagal balance (nLF/nHF) for 60 min after the CEPT trial, there were also significant decreases (P<0.01) in markers of vagal tone (RMMSD, nHF) for 60 min. There were no significant interactions between groups from rest to recovery from maximal exercise for any HRV variables. The overall change in ln LF/HF was of greater proportion in male participants(P<0.05) within 5 min. Conclusions  Our findings indicate that the change of autonomic recovery was difference between male and female within 5 min, and it takes longer than 60 min to recover following an acute bout of CPET trial.


2008 ◽  
Vol 20 (1) ◽  
pp. 28 ◽  
Author(s):  
NA Schie ◽  
A Stewart ◽  
P Becker ◽  
GG Rogers

Objective. Athletes frequently report training to music, yet there have been relatively few studies that have addressed the benefit of exercising with music. Design. Volunteer men and women (N=30), aged between 18 and 40 years, performed an initial familiarisation session. Part of this session involved the measurement of maximal oxygen consumption. With at least a 48-hour intervening period, this was then followed by a first 20-minute submaximal cycling session, at 80% of maximal oxygen consumption. At least 48 hours later a second submaximal cycling session was performed. Subjects were randomly divided into two groups. Group A cycled without music and group B cycled with music for the first submaximal cycling session. Subjects underwent the same testing procedure for the second submaximal cycling session, but this time group A cycled to music and group B cycled without music. Subjects served as their own controls. Setting. The study was performed in the physiology exercise laboratory, at the University of the Witwatersrand. Main outcome measures. During the submaximal sessions heart rate, perceived exertion (Borg scale) and plasma lactate concentration were assessed. Subjects completed a post-test questionnaire once both submaximal cycling sessions were completed. Results. There were no significant differences in physiological variables (change in plasma lactate and heart rate), nor were there any significant differences in Borg scale ratings when the subjects cycled with and without music. However, according to the post-test questionnaire 67% of subjects identified the cycling session with music to be easier than the session without music. Conclusion. Listening to music while performing submaximal cycling resulted in no physiological benefit. Yet, the cycling session done in conjunction with music was deemed, by the majority of the subjects, to be easier than the cycling session without music. South African Journal of Sports Medicine Vol. 20 (1) 2008: pp. 28-31


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