BACKGROUND: This study examined if the rating scale of perceived exertion (RPE) could be used to prescribe an individualized exercise intensity at the crossover point (COP) of substrate utilization and monitor such an individualized rehabilitation program in women with metabolic syndrome (MS). Secondly, the study investigated the effects of such a program. METHODS: Nineteen women were evaluated before and after 12 weeks of rehabilitation, which was individualized at RPE corresponding to their respective COP determined by indirect calorimetry. RESULTS: The women succeeded in regulating the exercise intensity using the targeted RPE (11.7 +/- 2.8 corresponding to 40 +/- 15 W) during the training program. Moreover, the rehabilitation program at RPE corresponding to the COP perceived between light and moderate by these women was sufficient to improve the metabolic and cardiovascular risk factors defining MS as well as the physical fitness in these women. Finally, this program, which allowed for a decrease in the prevalence of MS (-33%), was associated with a very high level of adhesion and compliance. CONCLUSIONS: This study suggests that an individualized aerobic rehabilitation program using target RPE seems to be effective and tolerable in women with MS.

BACKGROUND: This study investigated the effects of an exercise program at the intensity corresponding to the crossover point of substrate utilization (COP) on anthropometric measures, health-related quality of life (HRQoL) and cardiorespiratory fitness (i.e., peak oxygen uptake [(V)over dotO(2peak) and peak power output [P-peak) in women with metabolic syndrome (MetS).METHODS: Nineteen obese and post-menopausal women with MetS (age: 54.8 +/- 8.1 years, body mass: 89.0 +/- 12.2 kg, Body Mass Index: 34.5 +/- 4.0 kg/m(2)) followed a 12-week program consisting of three 45-minute sessions per week of cycle ergometer exercise. The imposed exercise intensity corresponded to COP. Before and after the program, HRQoL, (V)over dotO(2peak) and P-peak were measured and then compared.RESULTS: Body mass (89.0 +/- 12.2 vs. 86.2 +/- 11.0 kg), Body Mass Index (34.5 +/- 4.0 vs. 33.4 +/- 3.6 kg/m(2)), waist (10 +/- 10 vs. 100 +/- 9 cm) and hip (117 +/- 11 vs. 114 +/- 11 cm) circumferences, waist-to-hip ratio (0.91 +/- 0.07 vs. 0.88 +/- 0.07), fat mass (43.3 +/- 4.6 vs. 41.9 +/- 4.6%), fat-free mass (56.7 +/- 4.6 vs. 58.2 +/- 4.6%), (V)over dotO(2peak) (16.6 +/- 3.4 vs. 18.1 +/- 4.1 mL/min/kg) and P-peak (102 +/- 22 vs. 125 +/- 27 W) were significantly improved after the exercise program (P<0.05), but HRQoL showed no significant improvement on any subscale (i.e., physical functioning: performance limitation for physical activities including bathing and dressing, role physical: problems with work or other daily activities, bodily pain, general health, vitality, social functioning, role emotional and mental health; P>0.05).CONCLUSIONS: Although a 12-week exercise program at COP improved anthropometric measures and cardiorespiratory fitness in women with MetS, self-perceived HRQoL did not significantly improve. This finding may be linked to a significant but still insufficient reduction in body mass, probably because COP is too weak exercise intensity to induce important energy expenditure.

BACKGROUNDThe twofold aim of the study was to: 1) compare the gas exchange threshold (GET), the first oxyhemoglobin inflection point ([O2Hb]-T), and perceptual threshold as determined during an incremental exercise test, and 2) investigate the link between each threshold and time-to-exhaustion during heavy intensity exercise.METHODSFourteen competitive cyclists performed an incremental exercise test to exhaustion on a cycloergometer to determine the different thresholds and peak workload (Wpeak). The participants then performed a sub-maximal constant workload test (90% Wpeak) to exhaustion to determine time-to-exhaustion. The thresholds were identified from: 1) the first breakpoint in the oxygen uptake vs. carbon dioxide output curve (GET), 2) the [O2Hb]-T, and 3) a rating of 13 in perceived exertion (perceptual threshold: RPE13-T).RESULTSOxygen uptake at the different thresholds was not significantly different (P>0.05). Moreover, GET and [O2Hb]-T were significantly correlated: 1) to each other (r≥0.79; P≤0.001), and 2) to time-to-exhaustion (r=0.81 and r=0.72, respectively; P<0.01). RPE13-T, however, was not significantly correlated with the time-to-exhaustion (P=0.148).CONCLUSIONSThe anaerobic threshold as identified from GET was concomitant to [O2Hb]-T. Both thresholds were correlated to time-to-exhaustion, and could therefore be used as a performance index in middle-duration events.

INTRODUCTION:On the basis of theoretical evidence, intensity at the crossover point (COP) of substrate utilization could be considered as potential exercise intensity for metabolic syndrome (MetS). This study aimed to examine the effects of a training program at COP on exercise capacity parameters in women with MetS and to compare two metabolic indices (COP and the maximal fat oxidation rate point LIPOXmax®) with ventilatory threshold (VT). METHODS:Nineteen women with MetS volunteered to perform a 12-wk training program on a cycle ergometer, with intensity corresponding to COP. Pre- and posttraining values of anthropometric and exercise capacity parameters were compared to determine the effects of exercise training. The pre-post training change of COP, LIPOXmax®, and VT were also investigated. RESULTS:After training, anthropometric parameters were significantly modified, with reduction of body mass (3.0% ± 3.0%, P < 0.001), fat mass (3.3% ± 3.4%, P < 0.001), and body mass index (3.2% ± 3.4%, P < 0.001). Exercise capacity was improved after the training program, with significant increase of maximal power output (25.0% ± 18.4%, P < 0.001) and maximal oxygen uptake (V˙O2max, 9.0% ± 11.2%; P < 0.01). Lastly, when expressed in terms of power output, COP, LIPOXmax®, and VT occurred at a similar exercise intensity, but the occurrence of these three indices is different when expressed in terms of oxygen uptake, HR, or RPE. CONCLUSIONS:This study highlights the effectiveness of a 12-wk training program at COP to improve physical fitness in women with MetS. The relations between metabolic indices and VT in terms of power output highlight the determination of VT from a shorter maximal exercise as a useful method for determining metabolic indices in MetS.

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.

The present study examined the effects of a training program at a special exercise intensity-the crossover point of substrate utilization (COP)-on the metabolic abnormalities and cardiovascular risk factors in obese women with metabolic syndrome (MetS). Eighteen postmenopausal obese women with MetS (age, 54.8 +/- 8.4 years; height, 160 +/- 6 cm) followed a 12-week training program consisting of three 45-minute sessions/wk on a cycle ergometer. The intensity imposed during the training sessions corresponded to COP. Before and after the training program, anthropometric, biological, and blood pressure data were collected and compared. After the training program, body mass (88.4 +/- 12.3 kg vs. 85.7 +/- 11.1 kg), fat mass (43.2 +/- 4.8% vs. 41.8 +/- 4.8% body mass), body mass index (34.3 +/- 3.9 kg/m(2) vs. 33.2 +/- 3.6 kg/m(2)), and waist circumference (105 +/- 10 cm vs. 100 +/- 9 cm) were significantly lower (p < 0.01). Moreover, fasting plasma glucose was significantly lower after the training program (114 +/- 20 mg/dL vs. 107 +/- 15 mg/dL; p = 0.02) and the quantitative insulin-sensitivity check index was significantly higher (0.58 +/- 0.08 vs. 0.61 +/- 0.05; p = 0.05). A significant reduction in systolic blood pressure was also observed (141 +/- 15 mmHg vs. 129 +/- 11 mmHg; p = 0.02). After the program, the number of patients with fasting plasma hyperglycemia and arterial hypertension was significantly decreased by 54.4% and 44.4%, respectively, and the number of patients with MetS was nonsignificantly reduced by 22.2% (p = 0.10). The present study shows that a training program at COP is an efficient means to treat MetS. Copyright (C) 2014, The Society of Chinese Scholars on Exercise Physiology and Fitness. Published by Elsevier (Singapore) Pte Ltd. All rights reserved.

L'utilisation de la calorimétrie indirecte d'effort pourrait permettre d'individualiser la prescription de l'intensité d'exercice chez le patient présentant un syndrome métabolique (SM). L'objectif de cette étude est d'examiner l'effet d'un programme de réadaptation au point de croisement des débits d'oxydation glucidique et lipidique (PCGL) sur les anomalies métaboliques et les risques cardiovasculaires chez des femmes présentant un SM. 14 femmes présentant un SM (âge = 55,8 ± 8,5 ans; masse = 88,0 ± 13,1 kg; taille = 160,1 ± 5,8 cm) ont réalisé un test à l'effort maximal permettant d'évaluer la consommation pic d'oxygène (VO2pic) et un test de calorimétrie indirecte d'effort pour déterminer le PCGL. Les mesures de masse corporelle, circonférences de la taille et des hanches, pourcentage de masse grasse, tension artérielle et dosages sanguins (triglycérides, cholestérol total, HDL, LDL, glycémie, insuline, leptine) ont été effectuées. Puis, ces femmes ont suivi un programme de 12 semaines de réadaptation à l'effort constitué de 3 séances hebdomadaires de 45 minutes à PCGL sur bicyclette ergométrique. Après ce programme, ces paramètres ont tous été réévalués. Les valeurs obtenues avant et après la période de réadaptation étaient comparées par un test t de Student apparié. Les valeurs de VO2pic ont augmenté et les mesures anthropométriques et la moyenne de tension artérielle systolique de nuit étaient plus faibles après la période de réadaptation (p < 0,05). Cependant, les mesures sanguines n'étaient pas significativement modifiées après cette période hormis la glycémie à jeun qui diminuait (1,18 ± 0,22 vs 1,07 ± 0,16 g. L-1; p < 0,05. Les diminutions des anomalies métaboliques (i.e., modifications de la composition corporelle et amélioration du contrôle glycémique) et l'augmentation de la VO2pic attestent de l'efficacité de ce programme de réadaptation à l'effort individualisé au PCGL chez ces femmes.

Habituellement, il est recommandé de prescrire une intensité d'exercice initiale comprise entre 40 et 60 % de la consommation pic d'oxygène (VO2pic) chez les sujets ayant une faible condition physique. D'un point de vue pratique, d'autres auteurs préfèrent utiliser un pourcentage de la fréquence cardiaque de réserve (FCréserve), ou une valeur de perception de l'effort (RPE). L'objectif de cette étude est donc d'examiner la relation entre ces variables chez des patientes obèses. Soixante deux patientes obèses et sédentaires (âge : 50,7 ± 8,2 ans; masse corporelle : 103,6 ± 16,2 kg; taille : 162 ± 8 cm; indice de masse corporelle : 39,7 ± 6,4 kg/m2;; masse grasse : 46,6 ± 4,5 %) ont réalisé un test progressif sur ergocycle. Durant chaque palier, les pourcentages de VO2pic, de FCréserve et les RPE étaient mesurés. Les relations entre ces variables étaient ensuite étudiées. Des corrélations significatives étaient trouvées entre chaque variables (RPE – % VO2pic, r = 0,74; RPE – % FCréserve, r = 0,72; % VO2pic – % FCréserve, r = 0,85; p < 0,05). À 40 et 60 % VO2pic (i.e., l'intensité d'exercice recommandée pour les sujets ayant une faible condition physique), les RPE étaient de 9 et 12, tandis que les FCréserve étaient de 36 et 56 %, respectivement. À 36 et 56 % FCréserve, les RPE étaient de 10 et 12. Ces résultats suggèrent qu'un effort perçu entre 10 et 12 sur l'échelle RPE permet d'atteindre l'intensité d'exercice recommandée pour les patients obèses ayant une faible condition physique. Cependant, des études complémentaires doivent encore être menées pour confirmer que la prescription d'une intensité d'exercice à partir de RPE 10–12 permet réellement d'atteindre les effets physiologiques attendus chez des patientes obèses.

The purpose was to study the relationships between psychological factors and perceptually-based values (Ratings of Perceived Exertion: RPE and Estimated Time Limit: ETL). The researchers obtained the scores of several psychological factors (anxiety, extraversion-introversion, neuroticism-stability, self-esteem, motivation, psychological resistance and endurance, desire for success, social desirability, dynamism, competitiveness, activity control, risk-taking, emotional control, aggressiveness, sociability, cooperation, acceptance of a judgment, and leadership) among 23 cyclists. The cyclists performed a graded exercise test in which the researchers collected RPE and ETL at 150, 200, 250 and 300W. Correlations between RPE/ETL and psychological factors were examined. RPE was correlated with leadership, psychological resistance and endurance. ETL was significantly correlated with psychological endurance. These results suggest a link between psychological factors, effort perception, and the time limits predicted by teleoanticipation. These relationships varied according to intensity.

The ability to predict performance is of great interest for athletes and coaches. It is helpful for the selection of athletes to a team, the prescription of individualized training and the determination of the optimal pacing strategy. However, it is often difficult to judge the time to exhaustion without maximal exercise testing, which is often difficult to schedule during a competitive season. Consequently, the purpose of this review is to present a recent tool based on subjective prediction of time to exhaustion than can be achieved without requiring a maximal effort. This tool is the estimated time limit (ETL) scale. This review summarizes all experimentations that have studied the ETL scale. These studies suggest that the ETL scale may be used to predict time to exhaustion.

L'activité physique (AP) a des effets bénéfiques sur l'obésité. Pourtant, les patients obèses adhèrent peu aux programmes d'AP en partie à cause de la monotonie des exercices continus (EC) proposés. Pour pallier cela, des exercices intermittents (EI) peuvent être prescrits. L'objectif de cette étude est de déterminer l'exercice (EC vs EI) le mieux ressenti (procurant le plus de sensations positives) par des patientes obèses. Vingt huit patientes obèses (âge : 51,5 ± 7,0 ans; masse corporelle : 101,3 ± 17,3 kg; taille : 162 ± 7 cm; indice de masse corporelle : 38,5 ± 5,6 kg/m2;; masse grasse : 45,5 ± 4,5 %) ont réalisé un test progressif sur ergocycle pour déterminer leur seuil d'adaptation ventilatoire (SV). Ensuite, les sujets réalisaient 2 exercices sous-maximaux (EC et EI) avec une intensité relative (à 100 % SV) et une durée (32 minutes) identiques. Lors de l'EC, les patientes pédalaient continuellement à 100 % SV, tandis que lors de l'EI, la puissance oscillait toutes les 2 minutes entre 80 % et 120 % SV. Durant chaque exercice, le sentiment éprouvé (SE) et la fréquence cardiaque (FC) étaient relevés toutes les deux minutes, puis moyennés. L'exercice rapportant les SE les plus élevés correspondait à l'exercice le mieux ressenti. Les patientes obèses rapportaient des SE plus élevées lors de l'EI (0,3 ± 1,8 et 1,0 ± 1,5; p = 0,02). Les résultats individuels montre que 18 patientes avaient un SE plus élevé lors de l'EI, 7 patientes donnaient des SE plus élevées lors de l'EC, et 3 patientes rapportaient un même SE moyen. Lors des exercices, la FC moyenne était non significativement différente (115 ± 14 et 113 ± 16 bpm pour l'EC et l'EI, respectivement; p = 0,21). Ces résultats suggèrent une préférence pour les EI en comparaison aux EC. Les EI et les EC rapportaient des adaptations cardiaques similaires. Par conséquent, comme les EI semblent procurer plus de sensations positives que les EC, il peut donc être conseillé d'utiliser les EI en association aux EC, pour peut-être diminuer la monotonie des programmes d'AP, et accroître éventuellement l'adhésion des patientes obèses à ces programmes.

L'utilisation de la calorimétrie indirecte d'effort pourrait permettre d'individualiser la prescription de l'intensité d'exercice chez le patient présentant un syndrome métabolique (SM). L'objectif de cette étude est d'examiner l'effet d'un programme de réadaptation au point de croisement des débits d'oxydation glucidique et lipidique (PCGL) sur l'utilisation des substrats énergétiques à l'exercice chez des femmes présentant un SM. 14 femmes présentant un SM (âge = 55,8 ± 8,5 ans; masse = 88,0 ± 13,1 kg; taille = 160,1 ± 5,8 cm) ont réalisé un test à l'effort maximal permettant d'évaluer la consommation pic d'oxygène (VO2pic) et la puissance pic (Ppic), et un test de calorimétrie indirecte d'effort pour déterminer le PCGL. Lors de chaque palier, la perception de l'effort (RPE) et la consommation d'oxygène (VO2) étaient mesurées. Puis, ces femmes ont suivi un programme de 12 semaines de réadaptation à l'effort constitué de 3 séances hebdomadaires de 45 minutes à PCGL sur bicyclette ergométrique. Après ce programme, les 2 tests étaient réitérés. Les valeurs obtenues avant et après la période de réadaptation étaient comparées par un test t de Student apparié. Les valeurs de VO2pic et Ppic ont augmenté après la période de réadaptation (17,5 ± 4,1 ml. min-1.kg-1 vs 18,7 ± 4,4 ml. min-1.kg-1; 102,1 ± 25,5 W vs 122,1 ± 30,43 W; p < 0,05). Cependant, au PCGL, les valeurs de puissance n'étaient pas significativement modifiées après cette période (40,5 ± 16,8 vs 39,9 ± 9,6 % Ppic; p > 0,05). Seul la RPE au PCGL était significativement plus faible après la période (12,1 ± 2,8 vs 10,5 ± 3,2; p < 0,05). Ce programme de réadaptation au PCGL ne semble donc pas avoir d'effet sur le PCGL mais a permis de diminuer l'effort perçu chez ces femmes présentant un SM.

The most common tool used for measuring effort perception is the rating scale of perceived exertion (RPE) developed by Borg. This scale is also used for various outcomes in the general population. The validity and reliability of this scale have already been reported in obese patients. However, the relevance of measuring perceived exertion in obese patients is still poorly known. This review of the literature presents the Borg RPE scale (i.e., validity, reliability and recommendations) and its main advantages during graded exercise tests (e.g., comparison of physical capacity, predicting physiological variables, verifying exhaustion and exercise safety) and rehabilitation programs (e.g., individualized exercise intensity, evaluation of the impact of a rehabilitation program and even determining the perceptual preference) in obese patients. This review of the literature underlines the relevance and usefulness of the Borg RPE scale, which is still underused in obese patients. However, additional studies are still necessary before using this scale routinely in all obese patients (regardless of the severity of their obesity or associated complications).

Objective. - The objective was to examine the relationship between rating of perceived exertion (RPE) at the point of maximal lipids oxidation (LIPOXmax), physiological responses and psychological profile in trained competitive cyclists.Patients and methods. - Twenty-one competitive cyclists performed an exercise test in order to determine RPE at LIPOXmax. During this exercise test, physiological responses at LIPOXmax were measured. Moreover, a psychological profile for each cyclist has been evaluated from questionnaires (levels of anxiety, desire for success, self-esteem, psychological resistance and endurance, dynamism, competitiveness, activity control, risk-taking, emotional control, extroversion introversion, leadership, aggressiveness, sociability, cooperation, acceptance of a judgment, and social desirability). Multiple linear regression analysis was performed to determine the physiological and psychological factors linked to RPE at LIPOXmax.Results. - Only the percentage of maximal oxygen uptake ((V) over dotO(2) max), leadership and psychological endurance explained significantly the RPE at LIPOXmax.Conclusion. - More the cyclists have a low RPE at LIPOXmax, more their LIPOXmax (in (V) over dotO(2) max) was low. Cyclists with high level of leadership (i.e., persuasive, with command ability) and/or psychological endurance (i.e., persistent, obstinate) have lower RPE at LIPOXmax than the cyclists with lower level of leadership and/or psychological endurance. (C) 2011 Elsevier Masson SAS. All rights reserved.