Peripheral Ratings Of Perceived Exertion Research Articles

Acute effect of high-definition and conventional tDCS on exercise performance and psychophysiological responses in endurance athletes: a randomized controlled trial

Transcranial direct current stimulation (tDCS) has been used aiming to boost exercise performance and inconsistent findings have been reported. One possible explanation is related to the limitations of the so-called “conventional” tDCS, which uses large rectangular electrodes, resulting in a diffuse electric field. A new tDCS technique called high-definition tDCS (HD-tDCS) has been recently developed. HD-tDCS uses small ring electrodes and produces improved focality and greater magnitude of its aftereffects. This study tested whether HD-tDCS would improve exercise performance to a greater extent than conventional tDCS. Twelve endurance athletes (29.4 ± 7.3 years; 60.15 ± 5.09 ml kg−1 min−1) were enrolled in this single-center, randomized, crossover, and sham-controlled trial. To test reliability, participants performed two time to exhaustion (TTE) tests (control conditions) on a cycle simulator with 80% of peak power until volitional exhaustion. Next, they randomly received HD-tDCS (2.4 mA), conventional (2.0 mA), or active sham tDCS (2.0 mA) over the motor cortex for 20-min before performing the TTE test. TTE, heart rate (HR), associative thoughts, peripheral (lower limbs), and whole-body ratings of perceived exertion (RPE) were recorded every minute. Outcome measures were reliable. There was no difference in TTE between HD-tDCS (853.1 ± 288.6 s), simulated conventional (827.8 ± 278.7 s), sham (794.3 ± 271.2 s), or control conditions (TTE1 = 751.1 ± 261.6 s or TTE2 = 770.8 ± 250.6 s) [F(1.95; 21.4) = 1.537; P = 0.24; η2p = 0.123]. There was no effect on peripheral or whole-body RPE and associative thoughts (P > 0.05). No serious adverse effect was reported. A single session of neither HD-tDCS nor conventional tDCS changed exercise performance and psychophysiological responses in athletes, suggesting that a ceiling effect may exist.

Biomechanics of handcycling propulsion in a 30-min continuous load test at lactate threshold: Kinetics, kinematics, and muscular activity in able-bodied participants.

This study aims to investigate the biomechanics of handcycling during a continuous load trial (CLT) to assess the mechanisms underlying fatigue in upper body exercise. Twelve able-bodied triathletes performed a 30-min CLT at a power output corresponding to lactate threshold in a racing recumbent handcycle mounted on a stationary ergometer. During the CLT, ratings of perceived exertion (RPE), tangential crank kinetics, 3D joint kinematics, and muscular activity of ten muscles of the upper extremity and trunk were examined using motion capturing and surface electromyography. During the CLT, spontaneously chosen cadence and RPE increased, whereas crank torque decreased. Rotational work was higher during the pull phase. Peripheral RPE was higher compared to central RPE. Joint range of motion decreased for elbow-flexion and radial-duction. Integrated EMG (iEMG) increased in the forearm flexors, forearm extensors, and M. deltoideus (Pars spinalis). An earlier onset of activation was found for M. deltoideus (Pars clavicularis), M. pectoralis major, M. rectus abdominis, M. biceps brachii, and the forearm flexors. Fatigue-related alterations seem to apply analogously in handcycling and cycling. The most distal muscles are responsible for force transmission on the cranks and might thus suffer most from neuromuscular fatigue. The findings indicate that peripheral fatigue (at similar lactate values) is higher in handcycling compared to leg cycling, at least for inexperienced participants. An increase in cadence might delay peripheral fatigue by a reduced vascular occlusion. We assume that the gap between peripheral and central fatigue can be reduced by sport-specific endurance training.

Perceptually regulated training does not influence the differentiated RPE response following 16-weeks of aerobic exercise in adults with spinal cord injury.

This study investigated the effect of prolonged familiarisation with ratings of perceived exertion (RPE) on the peripheral (RPEP) and central (RPEC) RPE responses to moderate-vigorous exercise in adults with spinal cord injury (SCI). RPEP and RPEC characterise the exertion of the working musculature and cardiorespiratory systems, respectively. Nineteen participants (age, 41.4 ± 11.4 years; peak oxygen uptake, 19.2 ± 7.2 mL·kg-1·min-1) with chronic SCI were randomly assigned to RPE-guided (n = 11; EXP) or active control (n = 8; CON) groups. EXP performed 16-weeks of RPE-guided, supervised aerobic training for 20 min, twice weekly, at RPE 3-6 (Category-Ratio 10 scale). CON had access to the same exercise equipment but received no specific advice on their exercise-training regime. Participants completed a graded exercise test, using an arm crank ergometer at pre- and post-training to determine peak oxygen uptake, with RPEP and RPEC recorded every minute throughout tests. Sixteen weeks training did not improve peak oxygen uptake. RPE decreased post-training at 50% (p = 0.02) and 70% peak oxygen uptake (p = 0.03), though there was no effect of group at either intensity (p = 0.54, 0.42, respectively). At 70% peak oxygen uptake, RPEP was greater than RPEC (4.2 ± 1.7 vs 3.4 ± 1.8, p < 0.005). Training with RPE-guidance for 16 weeks had no additional effect on the differentiated RPE responses to moderate-vigorous exercise in adults with SCI. Novelty In adults with SCI, differentiated RPE responses were not different between those who did, and did not, perform 16 weeks of RPE-guided training. This challenges whether familiarisation with RPE is necessary to be an effective regulator of exercise intensity in this population.

An interdisciplinary examination of attentional focus strategies used during running gait retraining.

The aim was to investigate the biomechanical, physiological, and perceptual responses to different motor learning strategies derived to elicit a flatter foot contact. Twenty-eight rearfoot-striking recreational runners (age 24.9±2.8years; body mass 78.8±13.6kg; height 1.79±0.09m) were matched by age, mass, and height and assigned to one verbal cue group: internal focus of attention (IF), external focus of attention (EF), and a clinically derived condition (CLIN) incorporating an IF followed by an EF statement. Participants completed two treadmill runs at 10kmh-1 for 6minutes each: normal running (control) followed by the experimental condition (IF, EF, or CLIN). Lower limb kinematics, oxygen consumption ( ), and central and peripheral ratings of perceived exertion (RPE) were recorded for each run. Compared to the control condition, foot angle was reduced in the IF (difference=5.86°, d=2.58) and CLIN (difference=3.00°, d=1.31) conditions, but unchanged in the EF condition (difference=0.33°, d=0.14), while greater knee flexion at initial contact in the EF and CLIN conditions was observed (difference=-5.19°, d=1.97; difference=-3.66°, d=1.39, respectively). A higher was observed in the CLIN condition (difference=-4.56mLkg-1 min-1 , d=2.29), but unchanged in the IF (difference=-1.87mLkg-1 min-1 , d=0.94) and EF conditions (difference=-0.37mLkg-1 min-1 , d=0.19). All experimental conditions increased central and peripheral RPE (difference=-1.08, d=0.54 and difference=-2.39, d=1.33, respectively). Providing gait retraining instructions using an internally directed focus of attention was the most effective way to target specific changes in running kinematics, with no detrimental effect on physiological responses. Yet, perceptual effort responses increased regardless of the type of cue provided.

Improvements in Cycling but Not Handcycling 10 km Time Trial Performance in Habitual Caffeine Users

Caffeine supplementation during whole-/lower-body exercise is well-researched, yet evidence of its effect during upper-body exercise is equivocal. The current study explored the effects of caffeine on cycling/handcycling 10 km time trial (TT) performance in habitual caffeine users. Eleven recreationally trained males (mean (SD) age 24 (4) years, body mass 85.1 (14.6) kg, cycling/handcycling peak oxygen uptake (peak) 42.9 (7.3)/27.6 (5.1) mL∙kg∙min−1, 160 (168) mg/day caffeine consumption) completed two maximal incremental tests and two familiarization sessions. During four subsequent visits, participants cycled/handcycled for 30 min at 65% mode-specific peak (preload) followed by a 10 km TT following the ingestion of 4 mg∙kg−1 caffeine (CAF) or placebo (PLA). Caffeine significantly improved cycling (2.0 (2.0)%; 16:35 vs. 16:56 min; p = 0.033) but not handcycling (1.8 (3.0)%; 24:10 vs. 24:36 min; p = 0.153) TT performance compared to PLA. The improvement during cycling can be attributed to the increased power output during the first and last 2 km during CAF. Higher blood lactate concentration (Bla) was reported during CAF compared to PLA (p < 0.007) and was evident 5 min post-TT during cycling (11.2 ± 2.6 and 8.8 ± 3.2 mmol/L; p = 0.001) and handcycling (10.6 ± 2.5 and 9.2 ± 2.9 mmol/L; p = 0.006). Lower overall ratings of perceived exertion (RPE) were seen following CAF during the preload (p < 0.05) but not post-TT. Lower peripheral RPE were reported at 20 min during cycling and at 30 min during handcycling, and lower central RPE was seen at 30 min during cycling (p < 0.05). Caffeine improved cycling but not handcycling TT performance. The lack of improvement during handcycling may be due to the smaller active muscle mass, elevated (Bla) and/or participants’ training status.

Plasma cytokine and exertional responses in relation to exercise intensity and volume of exercising muscle mass during arm-crank ergometry.

This original study investigated the effect of submaximal exercise intensity and volume of contracting muscle mass on plasma inflammation-mediating cytokine and perceived exertional responses to acute arm-crank ergometry (ACE). Twelve recreationally active but upper limb untrained males performed 30 min of (i) low-intensity (40% peak oxygen uptake) ACE (LOW); (ii) moderate-intensity (60% peak oxygen uptake) ACE (MOD); and (iii) concurrent low-intensity (40% peak oxygen uptake) ACE plus lower limb cycle ergometry to match total power output in MOD (HYB). Plasma concentrations of interleukin (IL)-6, IL-10, IL-1ra, adrenaline, and cortisol were determined at rest, immediately postexercise, and 1 h and 2 h postexercise. Heart rate (HR) and differentiated ratings of perceived exertion (RPE) were also recorded. Plasma IL-6 concentrations were elevated (p < 0.05) immediately postexercise and 1 h postexercise (∼ 2.5-fold) in all trials and 2 h postexercise in MOD (3-fold). Plasma IL-1ra concentrations were elevated (p < 0.05) 2 h postexercise in MOD only (2-fold). No plasma IL-10, cortisol, and adrenaline responses were observed. HR and differentiated RPE were significantly higher during MOD than HYB and LOW. Peripheral RPE were significantly higher than central and overall RPE in each trial. Thirty minutes of moderate intensity ACE initiated a plasma cytokine response associated with the protective effect of regular exercise against cardiovascular and metabolic disease risk. Further work is required to establish an optimal intensity and duration of upper limb exercise to maximise the anti-inflammatory potential whilst managing the risk of over-use injury.

Prediction of peak oxygen uptake from differentiated ratings of perceived exertion during wheelchair propulsion in trained wheelchair sportspersons

To assess the validity of predicting peak oxygen uptake (VO(2peak)) from differentiated ratings of perceived exertion (RPE) obtained during submaximal wheelchair propulsion. Three subgroups of elite male wheelchair athletes [nine tetraplegics (TETRA), nine paraplegics (PARA), eight athletes without spinal cord injury (NON-SCI)] performed an incremental speed exercise test followed by graded exercise to exhaustion (VO(2peak) test). Oxygen uptake (VO₂), heart rate (HR) and differentiated RPE (Central RPE(C), Peripheral RPE(P) and Overall RPE(O)) were obtained for each stage. The regression lines for the perceptual ranges 9-15 on the Borg 6-20 scale ratings were performed to predict VO(2peak). There were no significant within-group mean differences between measured VO(2peak) (mean 1.50 ± 0.39, 2.74 ± 0.48, 3.75 ± 0.33 L min(-1) for TETRA, PARA and NON-SCI, respectively) and predicted VO(2peak) determined using HR or differentiated RPEs for any group (P > 0.05). However, the coefficients of variation (CV %) between measured and predicted VO(2peak) using HR showed high variability for all groups (14.3, 15.9 and 9.7%, respectively). The typical error ranged from 0.14 to 0.68 L min(-1) and the CV % between measured and predicted VO(2peak) using differentiated RPE was ≤11.1% for TETRA, ≤7.5% for PARA and ≤20.2% for NON-SCI. Results suggest that differentiated RPE may be used cautiously for TETRA and PARA athletes when predicting VO(2peak) across the perceptual range of 9-15. However, predicting VO(2peak) is not recommended for the NON-SCI athletes due to the large CV %s (16.8, 20.2 and 18.0%; RPE(C), RPE(P) and RPE(O), respectively).

Overall and peripheral ratings of perceived exertion during a graded exercise test to volitional exhaustion in individuals of high and low fitness

This study assessed the relationship between differentiated ratings of perceived exertion (RPE) and heart rate with oxygen uptake (VO2) during two graded exercise tests (GXT) to exhaustion on a cycle ergometer in 49 men and women (19-50 years) of high and low fitness. The study also assessed whether sub-maximal RPE values elicited during the GXTs could provide appropriate estimates of maximal aerobic power (VO2max) Peripheral RPE (RPEP) was higher than overall RPE (RPEO) at exhaustion in both groups (P<0.001), but the reliability of the terminal RPEO was higher (0.75 and 0.40, respectively). Fitness did not moderate the relationship of RPEO and RPEP with VO2 during the GXTs (P>0.05). However, the correlation for RPEP and VO2 was higher for women compared to men (0.98 and 0.96, respectively, P<0.05), although this is of little practical significance. In both groups, RPEO was almost as highly correlated with VO2 as heart rate during GXTs terminated at exhaustion (approximately 0.955-0.980). There were no differences between predicted and measured VO2max when VO2 values were extrapolated from sub-maximal RPEO (13, 15 and 17) intensities (42.1+/-12.5, 43.4+/-11.5, 44.2+/-11.3 and 43.3+/-10.0 ml kg(-1) min(-1), respectively). However, VO2max predicted from sub-maximal RPEP intensities was significantly lower (P<0.05). In conclusion, terminal RPEO was a more reliable measure of the RPE, and provided more accurate estimates of VO2max in healthy participants of high and low fitness when elicited from sub-maximal exercise intensities.

Ratings Of Perceived Exertion (RPE) During Elliptical Trainer, Treadmill And Recumbent Bike Exercise

Previous research has reported that dual action (arms & legs) elliptical trainer (ET) exercise elicits a higher physiological response than is perceived by the individual (Batte et al., 2003), which may be an important factor in an individual's selection of exercise equipment. To date, research has not compared this response across different types of exercise machines. PURPOSE To compare RPE, VO2 and HR across ET, a dual action (arms + legs) recumbent bike (DB), a treadmill (TM), and single-action (legs only) recumbent bike (SB). METHODS Ten males and four females (Age: 21±2 yr; Height: 177.9±10.0 cm; Weight: 77.4±13.7 kg) volunteered as subjects. Each subject warmed up for 5 min on a stationary upright bike, and then completed 6 minutes of exercise on each machine in randomized order with 3 min rest period between bouts. The metabolic workload was standardized across machines at ∼31.3 ml·kg−1·min−1. Heart rate (HR, bpm) and oxygen uptake (VO2, ml·kg−1·min−1) were sampled continuously during exercise, and overall RPE (O-RPE), central RPE (C-RPE), and peripheral RPE (P-RPE) were measured at the end of each exercise bout. A one-way repeated measures ANOVA was calculated to determine differences across machines. RESULTS No significant differences were found in VO2 (p=0.690; VO2ET: 31.1±6.2; VO2DB: 32.9±6.1; VO2SB: 30.8 ± 6.2; VO2TM: 30.6±3.0), HR (p=0.620; HRET: 164±17; HRDB:166 ± 16; HRSB: 167 ± 15; HRTM: 159±16), or C-RPE (p=0.256; C-RPEET: 11 ± 2; C-RPEDB: 12±2; C-RPESB: 12 ± 3; C-RPETM: 11±3) across machines, confirming that subjects worked at equivalent metabolic workloads. P-RPE was significantly less (p<0.002) in ET (10±2) versus DB (12±2); SB: (13±3); and TM (11±3). O-RPE was significantly less (p<0.007) in ET (11±2) and TM (12±3) versus DB (13±2) and SB (13±3). CONCLUSION These results indicate that P-RPE is less at similar metabolic workloads on the elliptical trainer than on single and dual action recumbent cycles and that O-RPE was reduced during ET and TM exercise when compared to SB and DB. These findings may have implications in selecting exercises that help promote exercise adherence.

PERCEIVED TASK EXPECTATIONS AND THE HUMAN WALK-RUN TRANSITION

PURPOSE To examine the effect of expected task duration on the preferred walk-run transition speed (PTS) in human locomotion and the hypothesis that the transition is made to minimize metabolic energy expenditure. METHODS Twelve male subjects performed treadmill locomotion trials lasting 50 s, 100 s, 5 min, 10 min, and 30 min. In each condition trial duration was known before testing. Speed was increased in 10 steps, every 0.1 m•s−1 starting at 1.4 m•s−1, and the PTS was recorded. Subjects also walked and ran at 40, 55, 70, 85, 100, 115, and 130% of the 30 min PTS while oxygen consumption data were recorded. The metabolically optimal transition speed (MOTS) was determined as the intersection of the metabolic transport cost functions (calculated as oxygen consumption divided by speed of locomotion) for extended walking and running. Subjects moved on the treadmill at – 90% of the MOTS in trials lasting 30 s, 3 min, 15 min, and 40 min. Running was more metabolically costly than walking at this speed. Subjects were informed regarding trial duration prior to testing in the 30 s, 3 min, and 15 min conditions, but not in the 40 min condition. Central and peripheral ratings of perceived exertion (RPE) were obtained at all speeds. RESULTS The PTS decreased with increasing task duration (2.22 ± 0.1 vs. 2.06 ± 0.1 m•s−1, p < 0.05) and the PTS for each duration condition occurred prior to the MOTS (p < 0.05). Central RPE values increased across the walk-run transition while peripheral RPE values decreased (p < 0.05). With increasing task duration, subjects preferred running to walking at – 90% of the MOTS (p < 0.05). Moreover, subjects experienced difficulty selecting the appropriate gait when the task duration was ambiguous. CONCLUSION The minimization of metabolic energy expenditure is not the primary trigger for the transition between walking and running. Rather, the transition is made to reduce peripheral sensations of effort associated with fast walking. Additionally, task-relevant information influences the decision whether to walk or run.

Perceived exertion and the preferred cycling cadence.

To determine whether an association exists between peripheral comfort level, as reflected by differentiated RPE measures, and the preferred cadences of subjects who differed in cycling experience and fitness level. Twelve experienced cyclists (C), ten runners (R), and ten less-trained noncyclists (LT), all of whom were male, pedaled at three power outputs (C, R: 100, 150, 200 W; LT: 75, 100, 150 W) and six cadences (50, 65, 80, 95, 110 rpm, and their freely chosen cadence) for 5 min per condition. Differentiated ratings of perceived exertion (RPE) were recorded during the fifth minute of the exercise. It was hypothesized that the preferred cadence selected by C, R, and LT would be the same as the cadence at which the peripheral RPE was minimized. Comparison of means failed to support this hypothesis. Irrespective of rating scale (peripheral, central, overall), the cadences at which RPE was minimized were lower than the preferred cadences, except for LT at 150 W, where there was no significant difference between the preferred cadence and the cadences at which the peripheral and overall RPE were minimized. C tended toward a more curvilinear RPE-cadence relationship compared with R and LT. Mean data for all groups showed that only the peripheral RPE decreased from 50 to 65 rpm, whereas peripheral, overall, and central RPE remained essentially unchanged from 65 to 80 rpm but increased from 80 to 110 rpm. There was a trend for the cadences at which RPE was minimized for C to be higher than the cadences that minimized RPE in either R or LT. For all groups, the cadences at which peripheral RPE was minimized were significantly higher than the cadences at which either the overall or central ratings were minimized. The small magnitudes of change in the RPE score across cadence, particularly in C and R, suggest that RPE may not be a critical variable in cadence selection during submaximal power output cycling.

A COMPARISON OF DIFFERENT TYPES OF MUSIC ON RATINGS OF PERCEIVED EXERTION AND HEART RATE DURING MODERATE INTENSITY EXERCISE 339

The use of ratings of perceived exertion to monitor intensity may become inaccurate if individuals use passive external distractors during exercise. The purpose of this study was to compare the effects of different types of music on ratings of perceived exertion (RPE) and heart rate (HR) during 20 min of moderate intensity exercise. Thirty physically active subjects (age 18-30 y) participated in the study. Each subject performed a graded exercise test on a cycle ergometer to determine peak aerobic power (VO2 peak). Four 20 min exercise sessions were performed on a cycle ergometer at an intensity equal to 70% of VO2 peak. The four sessions were randomly assigned from the following conditions: fast upbeat music (FM), classical music (CM), self-selected music (SM), and no music (NM). The exercise was performed in a soundproof, visually sterile room. Heart rate, overall RPE (O-RPE), peripheral RPE (P-RPE), and central RPE (C-RPE) were measured at 5 min intervals. Repeated measures ANOVAs and paired t-tests employing Bonferroni correction were used to identify differences among the means. No significant difference(p>0.05) was observed in HR among the four conditions indicating a similar metabolic intensity was achieved during each exercise bout. No significant differences were found for P-RPE, C-RPE and O-RPE among the four conditions(p>0.05). A significant time effect was found within each condition(p≤0.05), with each time measurement significantly different from all other measurements (p≤0.017). These results indicate that music does not act as a passive external distractor influencing peripheral, central or overall ratings of perceived exertion. The lack of differences among the treatment conditions indicates RPE is effective for monitoring exercise intensity when individuals use a passive external distraction such as listening to different types of music.

Metabolic Demands and Perceived Exertion during Cardiopulmonary Resuscitation

Emergency situations often require continuous execution of one-person cardiopulmonary resuscitation (CPR) for periods of time in excess of 30 minutes. The limited research which has examined the demands of the procedure has focused on central physiological measures, despite (1) the use of a subjective end-point for termination of CPR (i.e., exhaustion) as stated in professional guidelines, and (2) significant peripheral involvement in the form of muscular exertion, a phenomenon more closely linked to Ratings of Perceived Exertion (RPE) than to central factors. To examine subjective responses to performing CPR, 8 healthy, sedentary subjects [ M age = 20.8 (yr.) ± .4; weight (kg) 82.6 ± 7.1; height (cm) 183.7 ± 2.8] reported differentiated Ratings of Perceived Exertion (RPE) following 10 minutes of one-person CPR testing. While metabolic data observed during CPR support previous research suggesting that the energy demands of performing CPR are relatively low, both peripheral and over-all RPE were significantly higher than central (respiratory-metabolic) RPE. Over-all RPE was also significantly greater than peripheral RPE. The data suggest research investigating CPR demands based on central measures may underestimate actual as well as perceived demands of performing the procedure. In addition, the considerable interindividual variability in the relative energy cost (% VO2max) of performing one-person CPR suggests that the fitness level of the individual may be a limiting factor in the ability to perform CPR for extended periods of time.