Changes in ratings of perceived exertion and psychological affect in the early stages of exercise

Evaluating the effects of PeakATP® supplementation on visuomotor reaction time and cognitive function following high-intensity sprint exercise

The purpose of this study was to examine the effects of 14-days adenosine 5'-triphosphate (ATP) supplementation (PeakATP®) on reaction time (RT), multiple object tracking speed (MOT), mood and cognition. Twenty adults (22.3 ± 4.4 yrs., 169.9 ± 9.5 cm, 78.7 ± 14.6 kg) completed two experimental trials in a double-blind, counter-balanced, crossover design. Subjects were randomized to either PeakATP® (400 mg) or placebo (PLA) and supplemented for 14-days prior to each trial. During each trial, subjects completed a three-minute all-out test on a cycle ergometer (3MT), with measures of visuomotor RT [Dynavision D2 Proactive (Mode A) and Reactive (Mode B) tasks], MOT (Neurotracker), mood (Profile of Mood States Questionnaire; POMS) and cognition (Automated Neuropsychological Assessment Metrics; ANAM) occurring before (PRE), immediately post (IP) and 60 min post-3MT (60P). Subjects ingested an acute dose of the assigned supplement 30 min prior to completing PRE assessments for each trial. Trials were separated by a 14-day washout period. PeakATP® significantly attenuated declines in hits (p = 0.006, ηp2 = 0.235) and average RT (AvgRT, p = 0.006, ηp2 = 0.236) in Mode A, significantly improved AvgRT (p = 0.039, ηp2 = 0.174) in Mode B, and significantly reduced the total number of misses (p = 0.005, ηp2 = 0.343) in Mode B. No differences between treatments were noted for MOT, POMS or ANAM variables. In conclusion, these results indicate that PeakATP® maintains proactive RT and improves reactive RT following high-intensity sprint exercise suggesting that supplemental ATP may mitigate exercise induced cognitive dysfunction.

Preliminary feasibility and acute physiological effects of a single session of upper limb vibration training for persons with spinal cord injury

CONTEXT

Strong upper limb musculature is essential for persons with spinal cord injury (SCI) to operate a manual wheelchair and live independently. Targeted upper limb vibration may be a viable exercise modality to build muscle efficiently while eliminating some of the barriers associated with exercise for persons with SCI.

OBJECTIVE

The purpose of this study was to assess preliminary feasibility of completing a single exercise session of upper limb vibration and compare the acute physiological effects to a single session of standard dumbbell resistance exercise.

METHODS

Individuals with SCI performed seven upper limb exercises (1) isometrically using a vibrating dumbbell at 30 Hz for 60 s (n = 22) and (2) using a standard isotonic resistance protocol (n = 15).

RESULTS

Nineteen (86.4%) of 22 participants were able to perform all vibration exercises at 30 Hz but hold time success rates varied from 33% (side flies and front raises) to 95% (internal rotation). No significant differences were found between vibration exercise and standard resistance protocol for blood lactate, power output, and heart rate (P > 0.05). Perceptions of the training were positive, with most participants (>70%) expressing interest to train with vibration in the future.

CONCLUSIONS

Vibration training was not feasible for all participants, suggesting an individualized approach to starting weight and progression may be necessary. Similar acute physiological changes were seen between vibration exercise and standard resistance protocol, suggesting they could have similar benefits. Additional research is needed to determine if vibration exercise is feasible and beneficial to incorporate into a long-term training program.

A Study Using Power Cycling on the Affective Responses of a Low-Volume High-Intensity Interval Training to Male Subjects with Type 2 Diabetes in Different Physical Activity Status

High-intensity interval training (HIIT) has been shown in studies to enhance glucose management and cardiovascular well-being in patients with type 2 diabetes. In this study, we used power cycling to assess the physical activity levels of men with type 2 diabetes during a single low-volume HIIT session. First, fifty-six men with type 2 diabetes volunteered to take part in the study, and they were split into two groups based on the International Physical Activity Scale Short Form (IPA). To the first 1-4 labor bouts, both the sufficiently physically active and insufficiently physically active groups exhibited equal positive emotional reactions (p > 0.05). However, over time (about 5-10 times), both of them showed reduced emotional reactions, with a significant difference (p < 0.01). The insufficiently physically active group had lower mean emotional response, lowest effective response, and maximum effective response values than the sufficiently physically active group (p < 0.001), while the difference in RPE between the two groups was not statistically significant (p > 0.05). From the standpoint of emotional response, the proposed model shows that HIIT or reduced volume HIIT exercise prescriptions should be utilized with caution in physical activity programs for novices and less active and chronically sick persons. The frequency, intensity, and effects of low-volume HIIT on individuals' emotional reactions and health conditions in the T2DM group are also investigated. Furthermore, this low-volume HIIT program can be successfully applied in the real-world setting of people who are not physically active enough or who are chronically unwell.

Low-Volume High-Intensity Interval Training (HIIT) versus Moderate-Intensity Continuous Training on Body Composition, Cardiometabolic Profile and Physical Capacity in Older Women

OBJECTIVES

To compare the effect of low-volume HIIT to moderate-intensity aerobic training (MICT) on fat mass, cardiometabolic profile and physical capacity and confirm its feasibility in older women.

METHODS

Inactive older women (60-75 years) were randomly assigned to 8 weeks of either HIIT (75 min/week; n=9) or MICT (150 min/week; n=9). Body composition, fasting metabolic profile, cardiovascular risk (Framingham score), and physical capacity (senior fitness test, VO2peak) were assessed before and after the intervention. Feasibility was evaluated with completion rate (training compliance; dropout rate) and affective response (Feeling scale; pre- and post-exercise).

RESULTS

Total cholesterol, non-HDL-C levels and the Framingham risk score decreased in both groups (all p≤0.03). Although VO2peak remained unchanged, the 6MWT distance increased (p<0.0001), irrespective of the group. Completion rate and affective responses were not different between groups (all p≥0.38).

CONCLUSION

A short-term HIIT program is feasible and provides as much benefits as MICT in older women.

The Limits of Cognitive Reappraisal: Changing Pain Valence, but not Persistence, during a Resistance Exercise Task

Physiological discomfort is commonly cited as a barrier for initiating and persisting with exercise. Although individuals may think of physiological discomfort as determined by physical sensations, it can also be influenced by cognitive and emotional factors. We explored the impacts of interpreting the purpose of pain as a sign of muscle building (helpful) vs. a sign of muscle tearing and possible injury (harmful) and tested the effect of cognitive reappraisals, or shifting interpretations of pain, on exercise persistence and the subjective experience of discomfort during exercise. Seventy-eight participants were randomized to listen to voice recordings that framed exercise-related pain as helpful vs. harmful before participating in a standard muscular endurance test using the YMCA protocol. Although the two experimental groups did not differ in the overall number of resistance training repetitions achieved, participants who were asked to think about the benefits (rather than the negative consequences) of pain reported less negative pain valence during exercise. Thus, the experience of pain was influenced by appraisals of the meaning of pain, but differences in pain valence did not impact exercise persistence. Theoretical implications and applications for affect-based exercise interventions are discussed.

Feeling of Pleasure to High-Intensity Interval Exercise Is Dependent of the Number of Work Bouts and Physical Activity Status

Objectives

To examine the affective responses during a single bout of a low-volume HIIE in active and insufficiently active men.

Materials and methods

Fifty-eight men (aged 25.3 ± 3.6 years) volunteered to participate in this study: i) active (n = 29) and ii) insufficiently active (n = 29). Each subject undertook i) initial screening and physical evaluation, ii) maximal exercise test, and iii) a single bout of a low-volume HIIE. The HIIE protocol consisted of 10 x 60s work bouts at 90% of maximal treadmill velocity (MTV) interspersed with 60s of active recovery at 30% of MTV. Affective responses (Feeling Scale, -5/+5), rating of perceived exertion (Borg’s RPE, 6–20), and heart rate (HR) were recorded during the last 10s of each work bout. A two-factor mixed-model repeated measures ANOVA, independent-samples t test, and chi-squared test were used to data analysis.

Results

There were similar positive affective responses to the first three work bouts between insufficiently active and active men (p > 0.05). However, insufficiently active group displayed lower affective responses over time (work bout 4 to 10) than the active group (p < 0.01). Also, the insufficiently active group displayed lower values of mean, lowest, and highest affective response, as well as lower values of affective response at the highest RPE than the active group (p < 0.001). There were no differences in the RPE and HR between the groups (p > 0.05).

Conclusions

Insufficiently active and active men report feelings of pleasure to few work bouts (i.e., 3–4) during low-volume HIIE, while the affective responses become more unpleasant over time for insufficiently active subjects. Investigations on the effects of low-volume HIIE protocols including a fewer number of work bouts on health status and fitness of less active subjects would be interesting, especially in the first training weeks.

Type 2 diabetes exaggerates exercise effort and impairs exercise performance in older women

OBJECTIVE

Type 2 diabetes mellitus (T2DM) is associated with high levels of disability and mortality. Regular exercise prevents premature disability and mortality, but people with T2DM are generally sedentary for reasons that are not fully established. We previously observed that premenopausal women with T2DM report greater effort during exercise than their counterparts without diabetes, as measured by the Rating of Perceived Exertion (RPE) scale. We hypothesized that RPE is greater in older women with T2DM versus no T2DM.

RESEARCH DESIGN AND METHODS

We enrolled overweight, sedentary women aged 50-75 years with (n=26) or without T2DM (n=28). Participants performed submaximal cycle ergometer exercise at 30 W and 35% of individually-measured peak oxygen consumption (35% VO2peak). We assessed exercise effort by RPE (self-report) and plasma lactate concentration.

RESULTS

VO2peak was lower in T2DM versus controls (p=0.003). RPE was not significantly greater in T2DM versus controls (30 W: Control, 10.4±3.2, T2DM, 11.7±2.3, p=0.08; 35% VO2peak: Control, 11.1±0.5, T2DM, 12.1±0.5, p=0.21). However, lactate was greater in T2DM versus controls (p=0.004 at 30 W; p<0.05 at 35% VO2peak). Greater RPE was associated with higher lactate, higher heart rate, and a hypertension diagnosis (p<0.05 at 30 W and 35% VO2peak).

CONCLUSIONS

Taken together, physiological measures of exercise effort were greater in older women with T2DM than controls. Exercise effort is a modifiable and thereby targetable end point. In order to facilitate regular exercise, methods to reduce exercise effort in T2DM should be sought.

TRIAL NUMBER

NCT00785005.

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.

A perceptually regulated, graded exercise test predicts peak oxygen uptake during treadmill exercise in active and sedentary participants

The validity of predicting peak oxygen uptake ([Formula: see text]) in sedentary participants from a perceptually regulated exercise test (PRET) is limited to two cycle ergometry studies. We assessed the validity of a treadmill-based PRET. Active (n = 49; 40.7 ± 13.8 years) and sedentary (n = 26; 33.4 ± 13.2 y) participants completed two PRETS (PRET 1 and PRET2), requiring a change in speed or incline corresponding to ratings of perceived exertion (RPE) 9, 11, 13 and 15. Extrapolation of RPE: [Formula: see text] data to RPE 19 and 20 from the RPE 9-13 and 9-15 ranges were used to estimate [Formula: see text], and compared to [Formula: see text] from a graded exercise test (GXT). The [Formula: see text] :heart rate (HR) data (≥RPE 15) from the GXT were also extrapolated to age-predicted maximal HR (HRmax(pred)) to provide further estimation of [Formula: see text]. ANOVA revealed no significant differences between [Formula: see text] predictions from the RPE 9-15 range for PRET 1 and PRET 2 when extrapolated to RPE 19 in both active (54.3 ± 7.4; 52.9 ± 8.1 ml kg(-1) min(-1)) and sedentary participants (34.1 ± 10.2; 34.2 ± 9.6 ml kg(-1) min(-1)) and no difference between the HRmax(pred) method and measured [Formula: see text] from the GXT for active (53.3 ± 10.0; 53.9 ± 7.5 ml kg(-1) min(-1), respectively) and sedentary participants (33.6 ± 8.4, 34.4 ± 7.0 ml kg(-1) min(-1), respectively). A single treadmill-based PRET using RPE 9-15 range extrapolated to RPE 19 is a valid means of predicting [Formula: see text] in young and middle to older-aged individuals of varying activity and fitness levels.

The perceived exertion to regulate a training program in young women

The aim of this study was to compare the heart rate (HR) and the perceived exertion (PE) regulation of a training program in women and their effects on the cardiorespiratory responses. Twenty-seven women (mean age 22.4 ± 2.7 years) were randomly assigned to a control group (CG, n = 9), a heart rate group (HRG, n = 9), or a perceptive group (PG, n = 9). All subjects performed a maximal graded test (MGT) on a cycle ergometer before and after 6 weeks. The HR, V(O2)peak, maximal tolerated power (MTP), and PE were recorded during both MGTs. A 6-week interval training program was performed by both the HRG and PG. HR targets were used for the HRG and PE for the PG to readjust the power output. The results show that the V(O2)peak and the MTP increased significantly (p < 0.05) for both training groups, whereas the CG obtained no changes. As a consequence, PE could be a valuable tool to readjust the training load during an interval training program.

The psychological and physiological responses of sedentary individuals to prescribed and preferred intensity exercise

OBJECTIVES

Affective valence responses to exercise may influence adherence. According to a newly proposed dual-mode model, affective responses have been proposed to vary depending on whether exercise is undertaken above or below the anaerobic threshold. With the model in mind, the study objectives were to explore the impact of an above-lactate, below-lactate, and self-selected exercise condition on acute affective responses in sedentary individuals.

DESIGN

Using a repeated measures design, 12 volunteers participated in two prescribed intensity exercise conditions (above and below-lactate threshold) and one self-selected intensity exercise condition. The three conditions were randomized.

METHOD

An incremental walking protocol was used to identify exercise intensities that would elicit above- and below-lactate threshold work rates for each participant. The exercise conditions were completed on different days and each lasted for 20 minutes. Physiological and affective responses were recorded pre-exercise, during exercise, and post-exercise.

RESULTS

Affective responses were more negative in the above-lactate condition during exercise compared with the below-lactate and self-selected conditions. There were no differences between the conditions post-exercise. Participants exercised around the lactate threshold and at a significantly higher intensity in the self-selected compared with the below-lactate condition. Inter-individual variability in responses was greatest below the lactate threshold, with similar levels of variability in the self-selected and above-lactate conditions.

CONCLUSIONS

Data are consistent with the proposals of the dual-mode model and support the use of self-selected intensity with sedentary individuals to promote positive affective responses.

Pleasant for some and unpleasant for others: a protocol analysis of the cognitive factors that influence affective responses to exercise

BACKGROUND

At exercise intensities around ventilatory threshold (VT), the extent to which individuals experience pleasure or displeasure from the exercise varies between individuals. One source of this variability is proposed to be the cognitive appraisal that occurs during the exercise which influences the generation of the affective response. When individuals self-select their own intensity they choose to exercise around VT and experience more positive affective responses, again the explanation being that cognitive appraisal processes influence the choice of intensity and resulting affective response. However, the specific factors that comprise this appraisal process have not been thoroughly explored. In addition, it is not clear if activity status influences this appraisal and different cognitive factors play a role in the generation of affective responses. Therefore, the purpose of this study was to explore the cognitive factors that influence the affective response experienced during prescribed and self-selected intensity exercise in low-active and high-active women.

METHODS

Seventeen low-active and 15 high-active women (M age = 45 years, SD = 10) completed a graded exercise test and two 30 min bouts of treadmill exercise, one at a self-selected intensity and one prescribed at an intensity around VT. Using 'think aloud' procedures, every five min, the women were asked to provide an affective response and explain the thought processes that caused them to report that affective response. Using inductive content analysis, the verbal reports provided by the women were analysed for key themes and categories that emerged as explaining the factors that underpinned the generation of the affective response. Data from the low-active and high-active women were analysed separately.

RESULTS

Concepts relating to pre-exercise affective state, perceptions of ability, immediate and anticipated outcomes, attentional focus and perceptions of control emerged. The physiological demands of the exercise stimulus influenced affective responses through themes related to the interpretation of physiological symptoms and the physiological state of the body. No thematic differences emerged between high-active and low-active women.

CONCLUSION

Results highlight the complex interaction of psychological and physiological influences in producing an affective response to exercise and provide insight into how exercise can be structured to elicit positive affective responses.

Criteria for determination of maximal oxygen uptake: a brief critique and recommendations for future research

Although the concept of maximal oxygen uptake (V-dotO(2max)) was conceived as early as 1923, the criteria used to establish whether a true V-dotO(2max) has been attained have been heavily criticised. Consequently, an improvement in the methodology of the existing criteria, or development of new criteria, is required. In order to be valid across experimental studies, new or improved criteria need to be independent of exercise modality, test protocol and subject characteristics. One procedure that has shown potential for yielding valid V-dotO(2max) criteria is the verification phase, which consists of a supramaximal constant speed run to exhaustion performed after the incremental phase of a V-dotO(2max) test. A peak oxygen uptake (V-dotO(2peak)) in the verification phase that is similar (within the tolerance of measurement error, e.g. within 2%) to the V-dotO(2max) value attained in the incremental phase would indicate that a true V-dotO(2max) has been elicited. Verification of the maximal heart rate would also indicate that a subject has given a maximum effort. Although the validity of the present methodology for identifying an oxygen uptake (V-dotO(2)) plateau is questionable, a V-dotO(2) plateau criterion based on the individual slope of the V-dotO(2)-work-rate relationship should improve its validity. This approach also allows determination of the 'total V-dotO(2) plateau', which is in contrast to currently used V-dotO(2) plateau criteria that are based on the difference in V-dotO(2) between only two test stages or V-dotO(2) data points. The ratings of perceived exertion scale has been criticised for being a one-dimensional measure of physical effort and V-dotO(2max) criteria based on a multidimensional psychophysiological approach should increase validity. Visual analogue scales can be used to assess aspects such as muscular pain, determination and overall perceived effort. Furthermore, they are easy to complete and have demonstrated good reliability and validity in clinical and health settings. Future research should explore these and other potential approaches to developing new or improved V-dotO(2max) criteria, so that, ultimately, a standardised set of V-dotO(2max) criteria can be established. At present, however, the greatest challenge is identifying V-dotO(2max) criteria that remain valid across studies.

Prediction of maximal oxygen uptake from the ratings of perceived exertion and heart rate during a perceptually-regulated sub-maximal exercise test in active and sedentary participants

This study assessed whether the accuracy of predicting maximal oxygen uptake (VO2max) from sub-maximal heart rate (HR) and ratings of perceived exertion (RPE) values was moderated by gender and habitual activity. In total, 27 men and 18 women completed two GXTs to determine VO2max and three perceptually-regulated GXTs, incremented by RPE 9, 11, 13, 15 and 17. The RPE and HR were individually regressed against VO2max (approximately 0.96) to enable predictions of VO2max. The VO2max was predicted from three RPE ranges (9-17, 9-15, 9-13). The RPE ranges were extrapolated to RPE(19), RPE(20) and age-predicted maximal HR (HRmax(pred)). ANOVA revealed no differences between measured and predicted VO2max (P > 0.05) when the RPE range 9-17 was extrapolated to RPE(19) and HRmax(pred). Extrapolation of RPE 9-17 to RPE(20) overestimated VO2max (P < 0.05), but no differences were observed when predicted from the RPE ranges 9-15 and 9-13. The prediction of VO2max was not moderated by gender or activity status. Hierarchical regression analysis revealed that HR explained additional variance in VO2max when added to the RPE (2%). Hierarchical multiple regression analysis also indicated that VO2max was significantly correlated with power output at sub-maximal RPE values of 13 and 15 (P < 0.01) in men and women. The addition of HRmax(pred) improved the accuracy of the prediction equation for men (P = 0.05) but not for women. The study confirmed the validity of estimating VO2max from perceptually-regulated, sub-maximal GXT and indicated the potential utility of regression analysis to gauge appropriate sub-maximal exercise intensities.

Variation and homogeneity in affective responses to physical activity of varying intensities: an alternative perspective on dose-response based on evolutionary considerations

A model for systematic changes in patterns of inter-individual variation in affective responses to physical activity of varying intensities is presented, as a conceptual alternative to the search for a global dose-response curve. It is theorized that trends towards universality will emerge in response to activities that are either generally adaptive, such as moderate walking, or generally maladaptive, such as strenuous running that requires anaerobic metabolism and precludes the maintenance of a physiological steady state. At the former intensity the dominant response will be pleasure, whereas at the latter intensity the dominant response will be displeasure. In contrast, affective responses will be highly variable, involving pleasure or displeasure, when the intensity of physical activity approximates the transition from aerobic to anaerobic metabolism, since activity performed at this intensity entails a trade-off between benefits and risks. Preliminary evidence in support of this model is presented, based on a reanalysis of data from a series of studies.

The effects of music on the rate of perceived exertion and general mood among coronary artery bypass graft patients enrolled in cardiac rehabilitation phase II

The purpose of the study was to identify the effect of music on perceived exertion and mood in 30 coronary artery bypass graft patients during cardiac rehabilitation. The modified Borg Scale of Perceived Exertion (RPE) and the Rejeski Feeling Scale (FS) were the dependent variables. Group A subjects exercised with music and Group B subjects exercised without music as they rated their perceived exertion and mood. The use of music to reduce perceived exertion was not supported (p = 0.16). However, Group A members reported significantly enhanced mood while exercising to music and Group B members reported a significantly decreased mood without music (p = 0.0006). Enhancement of mood might lead to increased compliance with a regular exercise routine.

Gender comparison of RPE at absolute and relative physiological criteria

PURPOSE

The effect of gender on ratings of perceived exertion for the overall body (RPE-O), chest (RPE-C), legs (RPE-L), and arms (RPE-A (ski)) was determined.

METHODS

Comparisons were made at, a) absolute oxygen uptake (VO2, L x min(-1); mL x kg(-1) x min(-1)) and heart rate (HR, b x min(-1)) and b) relative VO2 (%VO2max/peak) and HR (% HRmax/peak) reference criteria. Nine male and 10 female subjects were compared using a perceptual estimation paradigm for treadmill (weight bearing), simulated ski (partial weight bearing), and cycle (nonweight bearing) exercise. RPE was determined by the Borg 15-category scale.

RESULTS

For each exercise mode, RPE-O, RPE-L, RPE-A (ski), and RPE-C were higher (P < 0.05) in the female than male cohort when compared at submaximal absolute VO2 criteria. RPE did not differ between female and male cohorts when compared at mode specific relative VO2 criteria. Differences in RPE-O, RPE-L, RPE-A (ski), and RPE-C were not found between female and male subjects when comparisons were made at both absolute and relative HR. Responses were consistent for the three exercise modes.

CONCLUSION

RPE did not differ between gender when comparisons were made at relativized VO2 and HR reference criteria at exercise intensities between 70 and 90% of mode specific maximal/peak values.

Cardio-respiratory responses to rowing ergometry and treadmill exercise soon after myocardial infarction

PURPOSE

The aim of this study was to compare the cardio-respiratory differences between rowing ergometry and treadmill exercise in beta-blocked men participating in exercise rehabilitation soon after myocardial infarction (postMI).

METHODS

Eleven males all receiving beta-blockade medication were measured for oxygen consumption (VO2), respiratory exchange ratio (RER), and rating of perceived exertion (RPE) at individualized submaximal exercise target heart rates (THR) during 6 min of exercise on each of a motorized treadmill and a rowing ergometer 2-6 wk (4.9 +/- 1.4) postMI.

RESULTS

The mean THR of the group, predetermined from an exercise ECG stress test, was 107 +/- 16 beats x min(-1). No significant difference was found between rowing versus treadmill VO2 (19.4 +/- 3.2 vs 19.7 +/- 4.2 mL x kg(-1) x min(-1); P = 0.53) or RPE (12.6 +/- 1 vs 12.7 +/- 1; P = 0.72). RER was significantly greater (P = 0.02) during rowing (0.99 +/- 0.07) compared with treadmill exercise (0.94 +/- 0.07).

CONCLUSION

Exercising at a specified submaximal THR during rowing versus treadmill exercise in beta-blocked men participating in very early cardiac rehabilitation represents the same VO2 and RPE. A significantly greater RER was, however, apparent during rowing compared with treadmill exercise; thus, agreement was shown with previous studies on healthy individuals where rowing ergometry was less metabolically efficient than treadmill exercise. The results suggest that establishing a THR from a standard treadmill stress test soon after MI is not only suitable for walking/treadmill exercise but also in setting exercise intensity for rowing ergometry.

Ratings of perceived exertion (RPE) during cycling exercises at constant power output

The purpose of the present investigation was to study the overall rating of perceived exertion (RPEov) according to the 6-20 scale proposed by Borg (1970) and muscular RPE (RPEmu) in exercises at constant load. The relationship between RPE and heart rate for three different loads was studied during exhausting exercises in 10 participants. Whether the drift of RPE during a 20 min exercise at constant load could be an index of the endurance time during long-lasting exercises at constant load was also investigated. At 1-week intervals, the participants performed cycling exercises up to exhaustion at 60, 73, and 86% maximal aerobic power (MAP) measured during an incremental test. Heart rate, RPEov, RPEmu and exhaustion time (tlim) were measured. The upward shift of the HRmax-RPE regressions was significant between 86, 73 and 60% MAP (p < 0.001) for RPEov and RPEmu. This result suggests that the equation HR = 10 x RPE proposed by Borg (1973) for incremental exercise is not valid for long-lasting exercise at constant load until exhaustion because the heart rate corresponding to a given RPE depends on load and time. Mean RPE increased linearly with time up to exhaustion. Unexpectedly, the relationships between RPEmu or RPEov and percentage of exhaustion time were similar for exercises at 60 and 73% MAP although the exhaustion times were very different (79.40 +/- 30.64 min versus 36.19 +/- 15.99 min, respectively) (p < 0.001). Consequently, it is likely that RPE was a subjective estimation of the hardness of exercise rather than the intensity of exercise. The RPE pattern at the beginning of long-lasting exercises at constant load (60 and 73% MAP) cannot be considered as a sensitive predictor of the point of self-imposed exhaustion for individuals. Indeed, the errors in the estimation of exhaustion time from extrapolation of RPE at the beginning of exercise were very large. Moreover, at 60% MAP, a steady-state in RPE was observed during 20 min in five subjects whose tlim were not longer than tlim of the other subjects. In addition, the data of the present study indicate that RPEmu could be more useful than RPEov in cycling.

Cortisol and affective responses to exercise

It has been reported that physically active individuals demonstrate attenuated cortisol responses to acute exercise compared to inactive individuals. Furthermore, a number of studies have demonstrated that increased cortisol levels are associated with negative affective states. Conversely, low cortisol levels have been demonstrated to be related to positive psychological constructs such as self-efficacy. However, the roles of activity history and adrenocortical activity in affective responses to acute exercise have not been examined. We therefore compared salivary cortisol, perceived exertion and affective responses to acute exercise in 13 male cross-country runners and 13 non-runners. The experimental trial consisted of a 30 min treadmill run at 60% VO2 max. Cortisol and affective responses were assessed before, during and after exercise; ratings of perceived exertion (RPEs) were recorded during exercise. Analyses of variance indicated no significant group differences in cortisol responses. However, there was a main effect for time (P< 0.05), with cortisol increasing from baseline to the 29th minute of exercise and then decreasing to 30 min post-exercise. Non-runners possessed greater perceptions of effort and negative affect during exercise compared to cross-country runners. Furthermore, the RPEs were positively related to post-exercise cortisol levels (P< 0.05), and affect and cortisol responses were inversely related 30 min post-exercise (P< 0.05). These results provide partial support for the hypothesis that cortisol levels are related to exercise-induced affective states.

Psychological affect at different ratings of perceived exertion in high- and low-active women: a study using a production protocol

The purpose of this study was to examine psychological affect at different ratings of perceived exertion (RPE) in 15 high- and 15 low-active women. Both groups performed three steady-state exercise bouts on a cycle ergometer at RPEs 9, 13, and 17 and reported their affect in the last 20 sec. of and 5 min. after each work rate. There were no differences between groups in percentage of maximal oxygen uptake (% VO2max) at each RPE. Low-active women reported feeling significantly more negative at RPE 17 than RPE 9 and less positive than the high-active women at RPEs 9, 13, and 17. In addition, all subjects reported more positive feelings 5 min. postexercise than in the last 20 sec. of exercising, especially at RPE 17. These results have implications for exercise prescription in groups differing in habitual activity levels.