The perceptually regulated exercise test is sensitive to increases in maximal oxygen uptake

What I see and what I feel: the influence of deceptive visual cues and interoceptive accuracy on affective valence and sense of effort during virtual reality cycling

Background

How we feel during exercise is influenced by exteroceptive (e.g., vision) and interoceptive (i.e., internal body signals) sensory information, and by our prior experiences and expectations. Deceptive visual cues about one's performance during exercise can increase work rate, without negatively impacting affective valence (good/bad responses) or perceived exertion. However, what is less understood is whether the perception of the exercise experience itself can be shifted, if work rate is held constant. Here we aimed to investigate whether deceptive vision-via illusory hills in a virtual reality (VR) cycling experience-alters affective valence and perceived exertion when physical effort is controlled. We also evaluated whether the accuracy with which one detects interoceptive cues influences the extent to which deceptive visual information can shift exercise experiences.

Methods

A total of 20 participants (10 female; 30.2 ± 11.2 yrs) completed three VR cycling conditions each of 10-min duration, in a randomised, counterbalanced order. Pedal resistance/cadence were individualised (to exercise intensity around ventilatory threshold) and held constant across conditions; only visual cues varied. Two conditions provided deceptive visual cues about the terrain (illusory uphill, illusory downhill; resistance did not change); one condition provided accurate visual cues (flat terrain). Ratings of affective valence (Feeling Scale) and of perceived exertion (Borg's RPE) were obtained at standardised timepoints in each VR condition. Interoceptive accuracy was measured via a heartbeat detection test.

Results

Linear mixed effects models revealed that deceptive visual cues altered affective valence (f2 = 0.0198). Relative to flat terrain, illusory downhill reduced affective valence (Est = -0.21, p = 0.003), but illusory uphill did not significantly improve affective valence (Est = 0.107, p = 0.14). Deceptive visual cues altered perceived exertion, and this was moderated by the level of interoceptive accuracy (Condition-Interoception interaction, p = 0.00000024, f2 = 0.0307). Higher levels of interoceptive accuracy resulted in higher perceived exertion in the illusory downhill condition (vs flat), while lower interoceptive accuracy resulted in lower perceived exertion in both illusory hill conditions (vs flat) and shifts of greater magnitude.

Conclusions

Deceptive visual cues influence perceptual responses during exercise when physical effort does not vary, and for perceived exertion, the weighting given to visual exteroceptive cues is determined by accuracy with which interoceptive cues are detected. Contrary to our hypotheses, deceptive visual cues did not improve affective valence. Our findings suggest that those with lower levels of interoceptive accuracy experience most benefit from deceptive visual cues, providing preliminary insight into individualised exercise prescription to promote positive (and avoid negative) exercise experiences.

Time Flies When You're at RPE13: How Exercise Intensity Influences Perception of Time

Hanson, NJ and Lee, TL. Time flies when you're at RPE13: How exercise intensity influences perception of time. J Strength Cond Res 34(12): 3546-3553, 2020-Previous studies have shown that there are some changes in our perception of time during exercise, but the relationship between intensity level and these perceptions is unclear. Therefore, the purpose of this study was to determine the effect of exercise intensity on prospective time estimations. Twenty-two trained runners (10 male, 12 female; age 25 ± 6 years) participated in three 30-minute treadmill runs that were perceptually regulated at rating of perceived exertion (RPE) levels of 13 ("somewhat hard"), 15 ("hard"), and 17 ("very hard"). Prospective time assessments, in which subjects estimated durations of 1, 3, 7, and 20 seconds, were obtained immediately before exercise, during (at 10 and 20 minutes), and after exercise. A 3 (RPE) × 4 (timepoint) × 4 (estimated duration) repeated-measures analysis of variance was completed. There was a significant main effect of RPE level (p = 0.013). Post hoc tests revealed that time estimations at RPE17 were significantly lower than those at RPE13 (p = 0.021). The main effects of timepoint and estimated duration were not significant (both p ≥ 0.05), and no interactions were present. However, there was a trend for time estimations to decrease in all conditions as exercise progressed, with a rebound after cessation of exercise. This study showed a clear effect of exercise intensity on time perception. Specifically, the subjects perceived time to pass by more slowly as intensity increased.

Submaximal, Perceptually Regulated Exercise Testing Predicts Maximal Oxygen Uptake: A Meta-Analysis Study

BACKGROUND

Recently, several authors have proposed the use of a submaximal 'perceptually regulated exercise test' (PRET) to predict maximal oxygen uptake ([Formula: see text]). The PRET involves asking the individual to self-regulate a series of short bouts of exercise corresponding to pre-set ratings of perceived exertion (RPE). The individual linear relationship between RPE and oxygen uptake (RPE:[Formula: see text]) is then extrapolated to the [Formula: see text], which corresponds to the theoretical maximal RPE (RPE20). Studies suggest that prediction accuracy from this method may be better improved during a second PRET. Similarly, some authors have recommended an extrapolation to RPE19 rather than RPE20.

OBJECTIVES

The purpose of the meta-analysis was to examine the validity of the method of predicting [Formula: see text] from the RPE:[Formula: see text] during a PRET, and to determine the level of agreement and accuracy of predicting [Formula: see text] from an initial PRET and retest using RPE19 and RPE20.

DATA SOURCES

From a systematic search of the literature, 512 research articles were identified.

STUDY ELIGIBILITY CRITERIA

The eligible manuscripts were those which used the relationship between the RPE≤15 and [Formula: see text], and used only the Borg's RPE scale.

PARTICIPANTS AND INTERVENTIONS

Ten studies (n = 274 individuals) were included.

STUDY APPRAISAL AND SYNTHESIS METHODS

For each study, actual and predicted [Formula: see text] from four subgroup outcomes (RPE19 in the initial test, RPE19 in the retest, RPE20 in the initial test, RPE20 in the retest) were identified, and then compared. The magnitude of the difference regardless of subgroup outcomes was examined to determine if it is better to predict [Formula: see text] from extrapolation to RPE19 or RPE20. The magnitude of differences was examined for the best PRET (test vs retest).

RESULTS

The results revealed that [Formula: see text] may be predicted from RPE:[Formula: see text] during PRET in different populations and in various PRET modalities, regardless of the subgroup outcomes. To obtain greater accuracy of predictions, extrapolation to RPE20 during a retest may be recommended.

LIMITATIONS

The included studies reported poor selection bias and data collection methods.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

The [Formula: see text] may be predicted from RPE:[Formula: see text] during PRET, especially when [Formula: see text] is extrapolated to RPE20 during a second PRET.

Prediction of peak oxygen uptake in children using submaximal ratings of perceived exertion during treadmill exercise

Purpose

This study assessed the utility of the Children’s Effort Rating Table (CERT) and the Eston–Parfitt (EP) Scale in estimating peak oxygen uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak) in children, during cardiopulmonary exercise testing (CPET) on a treadmill.

Methods

Fifty healthy children (n = 21 boys; 9.4 ± 0.9 years) completed a continuous, incremental protocol until the attainment of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak. Oxygen uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2) was measured continuously, and ratings of perceived exertion (RPE) were estimated at the end of each exercise stage using the CERT and the EP Scale. Ratings up to- and including RPE 5 and 7, from both the CERT (CERT 5, CERT 7) and EP Scale (EP 5, EP 7), were linearly regressed against the corresponding \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2, to both maximal RPE (CERT 10, EP 10) and terminal RPE (CERT 9, EP 9).

Results

There were no differences between measured- and predicted \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak from CERT 5, CERT 7, EP 5 and EP 7 when extrapolated to either CERT 9 or EP 9 (P > 0.05). Pearson’s correlations of r = 0.64–0.86 were observed between measured- and predicted \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak, for all perceptual ranges investigated. However, only EP 7 provided a small difference when considering the standard error of estimate, suggesting that the prediction of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak from EP 7 would be within 10 % of measured \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak.

Conclusions

Although robust estimates of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak may be elicited using both the CERT and EP Scale during a single CPET with children, the most accurate estimates of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak occur when extrapolating from EP 7.

Can previously sedentary females use the feeling scale to regulate exercise intensity in a gym environment? an observational study

BACKGROUND

Recent research suggests that the Feeling Scale (FS) can be used as a method of exercise intensity regulation to maintain a positive affective response during exercise. However, research to date has been carried out in laboratories and is not representative of natural exercise environments. The purpose of this study was to evaluate whether sedentary women can self-regulate their exercise intensity using the FS to experience positive affective responses in a gym environment using their own choice of exercise mode; cycling or treadmill.

METHODS

Fourteen females (24.9 years ± 5.2; height 166.7 ± 5.7 cm; mass 66.3 ± 13.4 kg; BMI 24.1 ± 5.5)) completed a submaximal exercise test and each individual's ventilatory threshold ([Formula: see text]) was identified. Following this, three 20 min gym-based exercise trials, either on a bike or treadmill were performed at an intensity that was self-selected and perceived to correspond to the FS value of +3 (good). Oxygen uptake, heart rate (HR) and ratings of perceived exertion (RPE) were measured during exercise at the participants chosen intensity.

RESULTS

Results indicated that on average participants worked close to their [Formula: see text] and increased their exercise intensity during the 20-min session. Participants worked physiologically harder during cycling exercise. Consistency of oxygen uptake, HR and RPE across the exercise trials was high.

CONCLUSION

The data indicate that previously sedentary women can use the FS in an ecological setting to regulate their exercise intensity and that regulating intensity to feel 'good' should lead to individuals exercising at an intensity that would result in cardiovascular gains if maintained.

Prediction of maximal or peak oxygen uptake from ratings of perceived exertion

Maximal or peak oxygen uptake (V˙O2 max and V˙O2 peak , respectively) are commonly measured during graded exercise tests (GXTs) to assess cardiorespiratory fitness (CRF), to prescribe exercise intensity and/or to evaluate the effects of training. However, direct measurement of CRF requires a GXT to volitional exhaustion, which may not always be well accepted by athletes or which should be avoided in some clinical populations. Consequently, numerous studies have proposed various sub-maximal exercise tests to predict V˙O2 max or V˙O2 peak . Because of the strong link between ratings of perceived exertion (RPE) and oxygen uptake (V˙O2), it has been proposed that the individual relationship between RPE and V˙O2 (RPE:V˙O2) can be used to predict V˙O2 max (or V˙O2 peak) from data measured during submaximal exercise tests. To predict V˙O2 max or V˙O2 peak from these linear regressions, two procedures may be identified: an estimation procedure or a production procedure. The estimation procedure is a passive process in which the individual is typically asked to rate how hard an exercise bout feels according to the RPE scale during each stage of a submaximal GXT. The production procedure is an active process in which the individual is asked to self-regulate and maintain an exercise intensity corresponding to a prescribed RPE. This procedure is referred to as a perceptually regulated exercise test (PRET). Recently, prediction of V˙O2max or V˙O2 peak from RPE:V˙O2 measured during both GXT and PRET has received growing interest. A number of studies have tested the validity, reliability and sensitivity of predicted V˙O2 max or V˙O2 peak from RPE:V˙O2 extrapolated to the theoretical V˙O2 max at RPE20 (or RPE19). This review summarizes studies that have used this predictive method during submaximal estimation or production procedures in various populations (i.e., sedentary individuals, athletes and pathological populations). The accuracy of the methods is discussed according to the RPE:V˙O2 range used to plot the linear regression (e.g., RPE9–13 versus RPE9–15 versus RPE9–17 during PRET), as well as the perceptual endpoint used for the extrapolation (i.e., RPE19 and RPE20). The V˙O2 max or V˙O2 peak predictions from RPE:V˙O2 are also compared with heart rate-related predictive methods. This review suggests that V˙O2 max (or V˙O2 peak ) may be predicted from RPE:V˙O2 extrapolated to the theoretical V˙O2 max (or V˙O2 peak) at RPE20 (or RPE19). However, it is generally preferable to (1) extrapolate RPE:V ˙ O 2 to RPE19 (rather than RPE20); (2) use wider RPE ranges (e.g. RPE ≤ 17 or RPE9–17) in order to increase the accuracy of the predictions; and (3) use RPE ≤ 15 or RPE9–15 in order to reduce the risk of cardiovascular complications in clinical populations.

Ramp-incremented and RPE-clamped test protocols elicit similar VO2max values in trained cyclists

PURPOSE

The present study compared the efficacy of ramp incremented and ratings of perceived exertion (RPE)-clamped test protocols for eliciting maximal oxygen uptake (VO2max).

METHODS

Sixteen trained cyclists (age 34 ± 7 years) performed a ramp-incremented protocol and an RPE-clamped protocol 1 week apart in a randomized, counterbalanced order. The RPE-clamped protocol consisted of five, 2-min stages where subjects self-selected work rate and pedal cadence to maintain the prescribed RPE. After completing both test protocols subjects were asked which they preferred.

RESULTS

The mean ± SD test time of 568 ± 72 s in the ramp protocol was not significantly different to the 600 ± 0 s in the RPE-clamped protocol (mean difference = 32 s; p = 0.09), or was the VO2max of 3.86 ± 0.73 L min(-1) in the ramp protocol significantly different to the 3.87 ± 0.72 L min(-1) in the RPE-clamped protocol (mean difference = 0.002 L min(-1); p = 0.97). Furthermore, no significant differences were observed for peak power output (p = 0.21), maximal minute ventilation (p = 0.97), maximal respiratory exchange ratio (p = 0.09), maximal heart rate (p = 0.51), and post-test blood lactate concentration (p = 0.58). The VO2max attained in the preferred protocol was significantly higher than the non-preferred protocol (mean difference = 0.14 L min(-1); p = 0.03).

CONCLUSION

The RPE-clamped test protocol was as effective as the ramp-incremented protocol for eliciting VO2max and could be considered as a valid alternative protocol, particularly where a fixed test duration is desirable.

Use of a perceptually-regulated test to measure maximal oxygen uptake is valid and feels better

A maximal, perceptually-regulated exercise test (PRETmax) whereby participants control the intensity according to preset ratings of perceived exertion (RPE) may induce more positive affective responses than a conventional 'experimenter controlled' incremental ramp test (Iramp). The authors aimed to assess (1) if a PRETmax could be used to measure VO(2max) and (2) if affective responses differed between the PRETmax and Iramp. Sixteen participants (age 20.5, s=1.2 y) completed a PRETmax which required them to adjust the resistance on a recumbent cycle ergometer to correspond to prescribed RPEs of 9, 11, 13, 15, 17 and 20 and an Iramp. Both tests ended with volitional exhaustion. Affect was recorded every minute throughout exercise using the Feeling Scale (FS). There was no difference (P>0.05) between VO(2max) measured by PRETmax (43.5, s=4.1 ml kg(-1) min(-1)) and Iramp (44.3, s=4.9 ml kg(-1) min(-1)). Participants reported feeling significantly less negative (P<0.001) throughout the PRETmax compared to Iramp (average mean difference FS = 1.4, s=0.1). The PRETmax has application in situations where the direct measurement of VO(2max) is required and the affective responses of the individual are considered to be important.