Effects of order of presentation of exercise intensities and of sauna baths on perceived exertion during treadmill running

Thirteen male subjects performed a running test on the treadmill consisting of four standard exercise intensities [65%, 75%, 85%, 95% maximal O2 uptake (VO2 max)] presented in ascending, descending or random order. At the end of each exercise intensity, O2 consumption, heart rate (fc), venous blood lactate concentration [( Ia]b) and perceived exertion were assessed. This last variable was determined according to the Borg nonlinear CR-20 scale. The same variables were also determined during exercise at a standard intensity (65% or 95% VO2 max) performed before and after a Finnish sauna bath. Ratings of perceived exertion showed a good test-retest reliability (r = 0.77); they were the same when the exercise intensity was expressed in relative (%VO2 max) or absolute (speed) terms, and were independent of the order of presentation of the exercise. The latter had no effect on fc either but it did, however, influence [Ia]b, which was significantly higher in the descending, as compared to the ascending or random modes of presentation. The sauna bath increased fc at a given exercise intensity, but left perceived exertion and [Ia]b unchanged. It was concluded that at least under the present experimental conditions, fc and venous [Ia]b do not play a major role as determinants of perceived exertion.     

Perceptual and physiological responses to cycling and running in groups of trained and untrained subjects

An interesting aspect, when comparing athletes, is the effect of specialized training upon both physiological performance and perceptual responses. To study this, four groups (with six individuals each) served as subjects. Two of these consisted of highly specialized individuals (racing cyclists and marathon runners) and the other two of non-specialized individuals (sedentary and all-round trained). Cycling on a cycle ergometer and running on a treadmill were chosen as modes of exercise. Variables measured included heart rate, blood lactate and perceived exertion, rated on two different scales. Results show a linear increase of both heart rate and perceived exertion (rated on the RPE scale) in all four groups, although at different absolute levels. Blood lactate accumulation, during cycling and running, differentiates very clearly between the groups. When heart rate and perceived exertion were plotted against each other, the difference at the same subjective rating (RPE 15) between cycling and running amounted to about 15-20 beats.min-1 in the non-specialized groups. The cyclists exhibited almost no difference at all as compared to 40 beats.min-1 for the runners. It can be concluded that specialized training changes both the physiological as well as the psychological response to exercise.     

Construct validity of the OMNI resistance exercise scale

This study examined the construct validity of the Adult OMNI Perceived Exertion Scale for Resistance Exercise (OMNI-RES). Forty (20 men and 20 women) subjects performed 1 repetition of the knee extension exercise at 40, 50, 60, 70, 80, and 90% of the 1 repetition maximum. Active muscle and overall body ratings of perceived exertion (RPE) were collected from the Borg 15-category RPE scale and the OMNI-RES immediately following each repetition. Construct validity was established by correlating RPE from the OMNI-RES with RPE from the Borg RPE scale using regression analysis. The results indicated a positive and linear relationship between RPE from the OMNI-RES and RPE from the Borg scale for both men and women. Validity coefficients ranged from r = 0.94 to 0.97. The high level of construct validity indicates that the OMNI-RES measures the same properties of exertion as the Borg RPE scale during resistance exercise and suggests that the 2 scales can be used interchangeably during resistance exercise.     

A comparison of the physiological exercise intensity differences between shod and barefoot submaximal deep-water running at the same cadence

The purpose of this investigation was to identify whether physiological exercise intensity differed with the use of aquatic training shoes (ATS) during deep-water running (DWR) compared to using a barefoot condition. Eight male intercollegiate (National Collegiate Athletic Association Division III [NCAA III]) varsity distance runners were videotaped from the right sagittal view while running on a treadmill (TR) and while barefoot in deep water at 60-70% of their TR VO2max for 30 minutes. Based on the stride rate of the barefoot DWR trial, a subsequent 30-minute session was completed while wearing ATS. Variables of interest were energy expenditure, oxygen consumption (VO2), heart rate, respiratory exchange ratio (RER), and rating of perceived exertion (RPE). Multivariate omnibus tests revealed statistically significant differences for energy expenditure (p < 0.011), VO2 (p < 0.001), RPE (p < 0.001), and RER (p < 0.002). The post hoc pairwise comparisons revealed significant differences between barefoot and shod DWR conditions for energy expenditure (p < 0.005) and VO2 (p < 0.002), representing a 9 and 7.6% increase in exercise intensity demand while running shod vs. barefoot. These comparisons also revealed significantly higher RPE and RER values while DWR than those found in TR. Wearing the ATS may be recommended as a method of statistically significantly increasing the exercise intensity while running in deep water as compared to not wearing a shoe. Shod compared to TR yields very small differences, which indicates that the shoes may help better match land-based running exercise intensities.     

A Cycling Movement Based System for Real-Time Muscle Fatigue and Cardiac Stress Monitoring and Analysis

In this study, we defined a new parameter, referred to as the cardiac stress index (CSI), using a nonlinear detrended fluctuation analysis (DFA) of heart rate (HR). Our study aimed to incorporate the CSI into a cycling based fatigue monitoring system developed in our previous work so the muscle fatigue and cardiac stress can be both continuously and quantitatively assessed for subjects undergoing the cycling exercise. By collecting electrocardiogram (ECG) signals, the DFA scaling exponent α was evaluated on the RR time series extracted from a windowed ECG segment. We then obtained the running estimate of α by shifting a one-minute window by a step of 20 seconds so the CSI, defined as the percentage of all the less-than-one α values, can be synchronously updated every 20 seconds. Since the rating of perceived exertion (RPE) scale is considered as a convenient index which is commonly used to monitor subjective perceived exercise intensity, we then related the Borg RPE scale value to the CSI in order to investigate and quantitatively characterize the relationship between exercise-induced fatigue and cardiac stress. Twenty-two young healthy participants were recruited in our study. Each participant was asked to maintain a fixed pedaling speed at a constant load during the cycling exercise. Experimental results showed that a decrease in DFA scaling exponent α or an increase in CSI was observed during the exercise. In addition, the Borg RPE scale and CSI were positively correlated, suggesting that the factors due to cardiac stress might also contribute to fatigue state during physical exercise. Since the CSI can effectively quantify the cardiac stress status during physical exercise, our system may be used in sports medicine, or used by cardiologists who carried out stress tests for monitoring heart condition in patients with heart diseases.     

The effects of specificity of training on rating of perceived exertion at the lactate threshold

To determine the effects of cycle and run training on rating of perceived exertion at the lactate threshold (LT), college men completed a 40-session training program in 10 weeks (n = 6 run training, n = 5 cycle training, n = 5 controls). Pre- and post-training variables were measured during graded exercise tests on both the bicycle ergometer and treadmill. ANOVA on the pre- and post-training difference scores resulted in similar improvements in VO2max for both testing protocols, regardless of training mode. The run training group increased VO2 at the LT by 58.5% on the treadmill protocol and by 20.3% on the cycle ergometer. Cycle trainers increased VO2 LT only during cycle ergometry (+38.7%). No changes were observed in the control group. No differences for RPE at the LT were found before or after training, or between testing protocols for any group. Perception of exercise intensity at the LT ranged from "very light" to "light". The relationship between RPE and %VO2max was altered by the specific mode of training, with trained subjects having a lower RPE at a given %VO2max (no change in RPE at max.). It was concluded that RPE at the LT was not affected by training, despite the fact that after training the LT occurs at a higher work rate and was associated with higher absolute and relative metabolic and cardiorespiratory demands.     

Comparison of kettlebell swings and treadmill running at equivalent rating of perceived exertion values

The purpose of this study was to compare metabolic demand of a kettlebell (KB) swing routine with treadmill (TM) running at equivalent rating of perceived exertion (RPE). Thirteen subjects (11 male, 2 female, age = 21.4 ± 2.1 years, weight = 73.0 ± 9.2 kg) completed a 10-minute KB swing routine consisting of 35-second swing intervals followed by 25-second rest intervals. Men used a 16-kg KB, and women used an 8-kg KB. After 48 hours of rest, the subjects completed a 10-minute TM run at equivalent RPEs as measured during the swing workout. Metabolic data were monitored each minute during each exercise using an automated cart, with the final 7 minutes used for analysis. The RPE and heart rate (HR) recorded at minutes 5, 7, 9, and 10 increased by 2-3 and 7-9%, respectively, for each exercise, producing a significantly increasing pattern but no significant difference between exercises. Average HR and RPE were not significantly different between KB and TM and averaged 90 and 89%, respectively, of age-predicted HRmax. Oxygen consumption, METS, pulmonary ventilation, and calorie expenditure were significantly higher for TM (25-39%) than for KB. Respiratory exchange ratio (TM = 0.94 ± 0.04, KB = 0.95 ± 0.05) and respiratory rate (TM = 38 ± 7, KB = 36 ± 4 b·min) were not significantly different between the exercises at any time point. During TM and KB exercises matched for RPE, the subjects are likely to have higher oxygen consumption, work at a higher MET level, and burn more kilocalories per minute during TM running than during KB swings. However, according to the American College of Sports Medicine standards, this KB drill could provide sufficient exercise stress to produce gains in aerobic capacity.     

Consistency of the counting talk test for exercise prescription

The purpose of this study was to assess the consistency of the counting talk test (CTT) method for estimating exercise intensity across various modes of exercise in healthy young adults. Thirty-six individuals completed the study, which required participation in 3 separate sessions within a 2-week time period. During the first session, the individuals completed a maximal effort treadmill test from which each individual's heart rate reserve (HRR) was calculated. During the second and third sessions, the subjects participated in 2 modes of exercise in each session for a total of 4 different modes of exercise. The individuals exercised at 40% HRR, 50% HRR, 60% HRR, 75% HRR, and 85% HRR. The heart rate (HR), CTT, and rating of perceived exertion (RPE) were recorded at each workload. Based on the individual's resting CTT (CTT(rest)), the %CTT for each exercise stage was then calculated. Pearson correlations demonstrated moderate to good correlations between the CTT and HRR methods and the CTT and RPE methods for estimating exercise intensity. This study found that for the individuals with CTT(rest) <25, moderate to vigorous intensity exercise as recommended by the American College of Sports Medicine HRR guidelines could be achieved by exercising at a level of 40-50% CTT(rest). Individuals with a CTT(rest) ≥25, exercising at a level of 30-40% CTT(rest) would place them in the moderate to vigorous exercise intensity range. A high degree of reliability was demonstrated using the CTT method across the various modes of aerobic exercise. As such, independent of the exercise mode, the CTT was found to be an easy and consistent method for prescribing moderate to vigorous aerobic exercise intensity.     

Neural control of the forearm cutaneous vasoconstrictor response to dynamic exercise.

This study was designed to evaluate the relative importance of intended effort ("central command") and of the absolute intensity of dynamic exercise to the cutaneous vasoconstrictor response to the onset of exercise in humans. Skin blood flow (laser-Doppler flowmetry) was measured from the forearm in six healthy individuals during 3-min periods of high- and low-intensity exercise with and without partial neuromuscular blockade. Cutaneous vascular conductance (CVC) was calculated from the ratio of skin blood flow to mean arterial pressure and expressed as a percent change from rest. A rating of perceived exertion (RPE) was expressed as a subjective measure of intended effort. Under control conditions, CVC decreased by 22% (median; range 7-42%, P less than 0.05) during high-intensity exercise [218 (186-268) W; RPE 16 (14-19) exertion units]. In contrast, during control low-intensity exercise [106 (88-128) W; RPE 10 (9-14) exertion units], during low-level exercise with curare [77 (54-98) W; RPE 13 (11-16) exertion units], and during maximal exercise with curare [106 (88-124) W; RPE 19 (18-20) exertion units], CVC did not change significantly. These results suggest that factors related to the activity of the exercising muscle and its metabolism rather than intended effort determine the cutaneous vasoconstrictor response to the initiation of intense dynamic exercise in humans.     

Crossmodal session rating of perceived exertion response at low and moderate intensities

Session rating of perceived exertion (SRPE) permits global effort estimations after an exercise bout and has shown promise for evaluating training load. However, factors mediating SRPE are not well understood. The purpose of this study was to compare SRPE between cycling and treadmill exercise at low and moderate intensities. In a counterbalanced order, male subjects (n = 7) completed a VO2max trial on a cycle ergometer and a motor-driven treadmill. Then, participants completed trials at 50 and 75% mode-specific VO2max on a cycle ergometer (BK75, BK50) and a treadmill (TM75, TM50) to achieve ～ 400-kcal energy expenditure per trial. Acute RPE (i.e., during exercise) at 5 minutes, midway, and test termination were recorded with SRPE (20-minutes postexercise) expressed as overall (SRPEO), legs (SRPEL), and breathing also recorded were heart rate (HR) and change in rectal temperature (ΔTrec). Significance was accepted at p ≤ 0.05. Repeated-measures analysis of variance revealed significantly greater SRPE for higher intensities within each mode. Crossmodal comparisons also show a higher SRPE at moderate (75% VO2max) intensities [SRPEO] = BK75: 7.6 ± 1.0, TM75: 6.9 ± 1.3) vs. lower (50% VO2max) intensities (BK50: 4.6 ± 1.4, TM50: 4.6 ± 1.1). Within modes, SRPE corresponded well with ΔTrec and HR. Acute RPE was linked with intensity and drifted upward across time. Results indicated that overall and differentiated SRPEs are magnified with exercise intensity with the corresponding disruption in internal environment potentially mediating subjective responses. From a practical application standpoint, SRPE provides a subjective assessment for immediate evaluation of daily training. Results indicate that, when using SRPE to monitor training, consideration should be given to responses across differing exercise modes.     

Ratings of perceived exertion in chronic obstructive pulmonary disease--a possible indicator for exercise training in patients with this disease

The purpose of this study was to evaluate the usefulness of ratings of perceived exertion (RPE) as an indicator of exercise intensity in patients with chronic obstructive pulmonary disease (COPD). The subjects were ten male patients with COPD, whose mean forced expiratory volume in 1 s was 1.09 1, SD 0.41, and ten healthy middle-aged men. Ramp incremental exercise on a cycle-ergometer was performed and RPE was determined by the Borg 15-point scale. The absolute oxygen uptake at each RPE was significantly greater in the healthy subjects than in the patients with COPD. However, oxygen uptake calculated as a percentage of maximal at any RPE did not differ significantly between the two groups. Arterial blood lactate concentration at points 15 to 19 on the RPE scale was increased in healthy subjects (P less than 0.05-P less than 0.001), while the dyspnoea index at points 11 to 19 on the RPE scale was higher in patients with COPD (P less than 0.05-P less than 0.001). The main complaints on stopping exercise were dyspnoea in the patients with COPD and fatigue in the healthy subjects. Although the nature of RPE may have been different in the two groups, RPE could be a possible indicator of exercise intensity when physicians prescribe exercise to patients with COPD.     

Heart rate and perceptual response to exercise with different pedalling speed in normal subjects and patients

The perceived exertion rating (RPE) scale of Borg was used to investigate the relationship between perceived exertion and pedalling rate. Normal subjects and patients with chronic obstructive lung disease (Cold) were studied in repeated test series. Work load, applied in a random order, varied from 2.5 to 10 mkp/s (patients) and 5 to 20 mkp/s (normals). Pedalling rate varied from 2.5 to 10 mkp/s (patients) and 5 to 20 mkp/s (normals). Pedalling rate varied from 40 to 60, 80, 100 rpm. At constant work load, RPE decreases during increasing pedalling rate. With respect to validity, RPE, showing a closer relationship to work load than to heart rate, seems to reflect perception of physical stress rather than perception of physiological strain. In addition, the results raise the question of standardization of pedalling rate in bicycle ergometry.     

Effect of training on the rating of perceived exertion at the ventilatory threshold

The purpose of this study was to determine the effect of training on the rating of perceived exertion (RPE) at the ventilatory threshold. College students were assigned to either training (n = 17) or control (n = 10) groups. Trainers completed 18 interval training sessions (five X 5 min cycling at 90-100% VO2max) and 8 continuous training sessions (40 min running or cycling) in 6 weeks. Pre- and post-training, cardiorespiratory, metabolic, and perceptual variables were measured at the ventilatory threshold during graded exercise tests on a cycle ergometer. Ventilatory threshold was that point above which VE X VO2-1 increased abruptly relative to work rate. Post-training means of trained and control subjects were compared using analysis of covariance, with pre-training values as covariates. Following training, the adjusted means for the trained subjects were significantly greater (p less than 0.05) than for controls for VO2max (6%), and for work rate (20%), VO2 (23%), and %VO2max (13%) at the ventilatory threshold. However, adjusted means for RPE at the ventilatory threshold were not significantly different (2%). Both before and after training, exercise at the ventilatory threshold was perceived as 'somewhat hard' to 'hard' (RPE = 13-15) by both groups. The relationship between RPE and %VO2max was altered by training, with trained subjects having a lower RPE at a given %VO2max. It is concluded that RPE at the ventilatory threshold is not affected by training, despite that after training the ventilatory threshold occurs at a higher work rate and is associated with higher absolute and relative metabolic and cardiorespiratory demands.     

Preferred method of selecting exercise intensity in adult women

Heart rate (HR) and rating of perceived exertion (RPE) are both recommended methods of determining exercise intensity for healthy adults. The purpose of this study was to determine how adult women self-select their exercise intensity during aerobic exercise. We interviewed 100 women exercisers who had been engaged regularly in an exercise program for at least 3 months to determine their method of gauging aerobic exercise intensity. Subjects exercised for about 45.1 +/- 21.4 minutes per session (4.4 +/- 1.4 times per week). The vast majority (84%) exclusively used self-selected effort perception to monitor their exercise intensity. Only 16% were familiar with an RPE chart. Although HR is touted heavily in fitness centers and on aerobic ergometers, self-selected effort perception (and not HR) is the method of choice by women who are experienced at aerobic exercise. It is recommended that fitness center personnel increase their efforts to educate the public regarding the appropriate use of effort perception as a method of gauging exercise intensity.     

Concurrent validity of an OMNI rating of perceived exertion scale for bench stepping exercise

To develop and validate a modified OMNI rating of perceived exertion (RPE) scale for use during bench stepping exercise (OMNI-BS). Thirty women (age: 19.8 ± 1.8 years) undertook 2 experimental trials, separated by 7 days. Concurrent validity was established by examining the relation between physiological criterion variables, oxygen consumption (VO2), and heart rate (HR), with the concurrent variable, RPE from OMNI-BS, during 2 trials in which the intensity increased linearly (test 1) and intermittently (test 2). The first test consisted of 3-minute stages. Subjects stepped up and down on the bench at 120 b·min(-1). The test was terminated owing to subject fatigue. Exercise intensity increased as bench height increased every 3 minutes. The second test consisted of three 3-minute exercise bouts that reproduced exercise stage 1 (low intensity), stage 3 (moderate intensity), and stage 5 (high intensity) performed in the first test. The order of these 3 exercise bouts was counterbalanced. Intraclass correlation analysis from experimental trials indicated a strong positive association between RPE and VO2 (r = 0.96 and r = 0.95) and HR (r = 0.95 and r = 0.95). Concurrent validity for the OMNI-BS RPE scale was established for women performing bench stepping exercise.     

Effects of the production of perceived exertion during cycle ergometry

Physiological and biomechanical effects of aerobic exercise varying in intensity were studied on the basis of the subjects’ perceived exertion. It was demonstrated that exercise regulated with the use of a 50–100 rating scale was characterized by reliably stable heart-rate and respiratory reactions and biomechanical responses. The relative working heart rate (HR) expressed in percent of the individual HRmax was found to be closely correlated with the values on the 50–100 scale within a wide range during exercise with constant or increasing perceived exertion.     

Effects of delayed onset muscle soreness on selected physiological responses to submaximal running

This study examined the effects of delayed-onset muscle soreness (DOMS) on selected physiological responses to submaximal exercise. Seven male and four female subjects (Ss) aged 21-37 years completed two submaximal running sessions at an individualized pace corresponding to a blood lactate concentration (bLa) of approximately 2.5 mmol x L(-1). Following the first session (T1), Ss performed a series of lower extremity resistance exercises designed to induce DOMS. Subjects were then retested (T2) 24-30 hours later, during which time all Ss experienced DOMS. Oxygen uptake, heart rate (HR), respiratory exchange ratio, rating of perceived exertion (RPE), and bLa were measured every 6 minutes. Significant trial effects (p < 0.05) were observed for HR and RPE. HR was significantly higher during T1 at minutes 6 and 12 (p < 0.05), and RPE values were significantly higher at T2 during all recording periods (p < 0.05). Results from this study suggest that DOMS does not affect submaximal oxygen uptake. However, DOMS does appear to affect one's perception of effort.     

Differential perceived exertion measured using a new visual analogue scale during pedaling and running

The purpose of this study was to evaluate the differential perceived exertion measured using a new set of Visual Analogue Scales (VAS) during pedaling and running. The subjects were eleven healthy males. They performed an incremental maximal test and then three 4-min stages of exercise, for both pedaling and running. During the tests, VO2, V(CO2), V(E), f, and HR were monitored continuously. Bla and perceptual variables including VAS consisting of four scales (VAS 1-VAS 4) and Borg's RPE were measured at the end of each stage. Although the VO2 (%VO2max)) and HR for both pedaling and running were not significantly different, Bla in pedaling was significantly higher than that in running. A significant interaction (mode, stage) was also obtained. The VAS 1 of pedaling was significantly higher than that of running. A significant interaction in VAS 1 (mode, stage) was obtained. The VAS 2 of pedaling was significantly higher than that of running. The subjects indicated that local pain became stronger than central pain in pedaling, but they were almost equal in running. In both pedaling and running, leg pain became stronger than arm pain (VAS 3). VAS 4 showed that during running, breathing difficulty and heart pain were almost equal in perceived intensity. However, during pedaling, breathing difficulty became greater than heart pain. Thus, a new four-part visual analogue scale was found to be useful for monitoring exercise intensity. In addition, the new VAS gave us more information in relation to the differential perceived exertion reflected in the different physiological responses obtained by different exercise modes.     

Training state improves the relationship between rating of perceived exertion and relative exercise volume during resistance exercises

ABSTRACT: Testa, M, Noakes, TD, and Desgorces, F-D. Training state improves the relationship between rating of perceived exertion and relative exercise volume during resistance exercises. J Strength Cond Res 26(11): 2990-2996, 2012-The aim of this study was to investigate how the rating of perceived exertion (RPE) during resistance exercises was influenced by the exercise volume and athletes' training state. Eighty physical education students (well trained, less well trained, and novices) rated their perceived exertion of multilift sets using the category-ratio scale. These sets were performed with moderate (60-80% of 1-repetition maximum [1RM]) and heavy loads (80-100% of 1RM) involving low volume of exercise (5.5 ± 1.1 reps for moderate and 1.3 ± 0.4 reps for the heavy load) and high volume of exercise (moderate load: 17.5 ± 2.1 reps; high load: 2.9 ± 0.6 reps). The exercise volume of the sets was expressed relatively to individual maximal capacities using the maximum number of repetition (MNR) for the load lifted. General linear model describes that RPE was related to MNR % with a training state effect (p < 0.01) observed only for sets involving a low MNR % and without effect of absolute volume and exercise intensity (high MNR sets: adjusted R = 0.65 and 0.78 and low MNR sets adjusted R = 0.37 and 0.34 in low MNR tests). High standard errors of estimated relative volume appeared when using the RPE from low exercise volume sets (12.8 and 14.4% of actual relative volume). Coaches should consider the RPE resulting from high exercise-induced physical strain to estimate the actual relative volume and to estimate the individual MNR at a given load.