Safety of using the adult OMNI Resistance Exercise Scale to determine 1-RM in older men and women

Older adults may be susceptible to injury during high-intensity resistance exercise. It has been suggested that it may be more protective to predict one-repetition maximum (1-RM) than to measure it because of the high intensity associated with 1-RM testing, but it may be necessary to measure 1-RM for functional, diagnostic, or clinical purposes. The method of using the OMNI Resistance Exercise Scale (OMNI-RES) was examined as a guide for hexagenarian adults in estimating 1-RM. 22 healthy men (M age = 64.3 yr., SD = 3.2) and 27 women (M age = 63.8 yr., SD = 2.8) volunteered. After two weeks of orientation, participants used a predetermined rating of perceived exertion to select resistance in the assessment of 1-RM and again after 12 weeks of training. At the 1-RM trials, participants were asked to report soreness or injury during or after the exercise sessions. There were no reported incidences of injury during the current investigation. The current results provide a practical method to estimate 1-RM in older adults. As such, the OMNI-RES can be used safely in a potentially at-risk population.     

Lactate threshold prediction by blood glucose and rating of perceived exertion in people with type 2 diabetes

The validity of rating of perceived exertion (RPE) in predicting lactate threshold during an incremental test was analyzed in 15 men with type 2 diabetes (M age = 53.4 yr., SD = 12.9). Blood glucose, lactate, and minute ventilation (VE)/VO2 responses identified the lactate, ventilatory, and glucose thresholds. Workloads (W) corresponding to RPEs 12, 13, 14, and 15 were determined. Second-order polynomials fit to VE/W and [lac]/W ratios corresponding to RPEs of 9-10, 12-13, and 16-17 also identified workloads above which there was an overproportional increase in VE and [lac]. These workload breakpoints did not differ, although at RPE 12 underestimated and at RPE 15 overestimated lactate threshold. RPE 13 and 14 and the responses of VE/W and [lac]/W to submaximal exercise accurately predicted lactate threshold.     

Validity and reliability of a Cantonese-translated rating of perceived exertion scale among Hong Kong adults

This study assessed the validity and reliability of the Cantonese-translated version of the Borg 6-20 Rating of Perceived Exertion (RPE) scale during continuous incremental cycle ergometry by Hong Kong adults. A total of 54 participants (25 males and 29 females), ages 22.2 +/- 4.7 yr., volunteered to participate. They performed two trials of identical continuous incremental cycling exercise 1 wk. apart for the reliability test. The objective measures of exercise intensity (heart rate, power output, and oxygen consumption) and the subjective measure of effort (RPE) were obtained during the incremental exercise. Significant (p < .01) Pearson correlations were found when RPE values were correlated with heart rate (rs > or = .73), power output (rs > or = .69), and oxygen consumption (rs > or = .68). The overall test-retest intraclass correlation (R = .92) indicated that the scale was reliable. In conclusion, this Cantonese scale for rating of perceived exertion appears to be a valid and reliable psychophysiological tool to measure perceptions of exertion during controlled cycle ergometer exercise by Hong Kong adults.     

Relations between perceptual and physiological response during incremental exercise followed by an extended bout of submaximal exercise on a cycle ergometer

The purpose of this study was to examine the relations of ratings of perceived exertion (RPE) of the legs, chest, and overall body with physiological responses (heart rate and oxygen uptake) both during incremental cycling exercise and the recovery stage (submaximal light exercise after total exhaustion). Subjects were 10 healthy university males ages 18 to 23 years (M age=20.5 yr., SD=1.4 yr.) who performed incremental cycling exercise until exhaustion after 1-min. rest and unloaded cycling for 2 min. They then continued to exercise at a constant load of 30 Watts (used for cooling down; recovery stage) for a total of 25 min. Oxygen uptake and heart rate were measured, and three types of RPE were done; Respiratory (chest; RPE-R), Peripheral (legs; RPE-P), and Overall (overall body; RPE-O) during the exercise and recovery stage. All variables during exercise and RPE-R and RPE-P during recovery stage showed significant linear changes. RPE-O and physiological exercise intensity (oxygen uptake and heart rate) in the recovery stage showed significant curvilinear changes (quadratic). RPE-P were significantly higher than RPE-R both during exercise and the recovery stage and the variables highly correlated (r > or = .88, p < .05). At the point of exhaustion, RPE-P and RPE-O almost reached a peak, but RPE-R did not. In the exercise period until exhaustion, the regression coefficient of RPE-R (.38) was significantly lower than that of RPE-P (.56) and RPE-O (.50), and RPE-R increased according to an increase of the incremental load, but the amount was significantly lower than those of RPE-P and RPE-O. In the recovery stage after exhaustion, the regression coefficient of RPE-O (-1.35) was significantly greater than that of RPE-P (-1.07). A decrease in RPE-O corresponded to a decrease in heart rate and oxygen uptake, but RPE-P did not, and the recovery of RPE-P tended to be late. The results suggest that relations for the physiological responses of heart rate, oxygen uptake, and RPE, and between each RPE in the recovery stage differed from those during exercise until exhaustion.     

Differentiated ratings of perceived exertion and physiological responses during aerobic dance steps by impact/type of arm movement

Overall ratings of perceived exertion, i.e., undifferentiated RPE, are often used as indicators of exercise intensity during walking, jogging, and cycling; however, conflicting results concerning RPE during aerobic dance exercise have been reported, and the use of differentiated RPE, i.e., local RPE and central RPE, has not been investigated. The purposes of this study were to assess local, central, and over-all RPE, and physiological responses [heart rate (HR); % HRmax; absolute and relative VO2;% VO2 max, ventilation (VE), ventilatory equivalent (VE.VO2(-1); and oxygen pulse] during aerobic dance exercise varied by Arm Movement (Static Arm vs Dynamic Arm) and Impact (High vs Low). Trained women (N = 25; max VO2 = 50.4 +/- 7.5 ml.kg-1.min.-1) completed four aerobic dance steps. No RPE were significantly correlated with heart rate or VO2; however, for all steps all RPE were significantly (r = .40-.62) correlated with VE.VO2(-1) or VE. No interactions were present for RPE or physiological variables, and main effects were noted for Impact and Arm Movement. All RPE were greater for High Impact and for Static Arm Movement. Because VE and VE.VO2(-1) were correlated with Overall RPE for all steps, this may suggest that participants "attended to" perceived changes in respiratory phenomena during aerobic dance exercise. It appears that during combined arm-and-leg aerobic dance exercise the use of Overall RPE is sufficient to assess perceptual sensations associated with the intensity of the exercise. Changes in Overall RPE were proportionate to objective measures of exercise intensity, i.e., HR and VO2; however, it is recommended that both HR and Overall RPE be used to assess fully a participant's objective and subjective responses during aerobic dance exercise.     

Asymmetry of force fluctuation during low and moderate intensity isometric knee extensions

The purpose of this study was to investigate the asymmetry of force fluctuation during isometric knee extension at low and moderate intensities. 11 healthy men (M age = 21 yr., SD = 1) performed unilateral force matching tasks; sustained isometric knee extension at 20% and 30% maximal voluntary contraction (MVC). During the tasks, a mechanomyogram was measured by an accelerometer arrangement placed on the vastus lateralis. Although force fluctuation was not significantly different between the two legs at 20% MVC, it was higher in the left (weaker) leg than in the right (stronger) leg at 30% MVC. A significant difference in mean power frequency of the mechanomyographic signal between the two legs was also observed only at 30% MVC. These results suggest that the asymmetry of force fluctuation during isometric knee extension was not statistically significant at low intensity; however, it was significant at moderate intensity. These differences in force fluctuation between intensities might be influenced by different motor-unit firing rates in active muscle.     

Perceived exertion during resistance exercise by children

This pilot study examined the validity of a new scale of perceived exertion during acute bouts of resistance exercise in young children. The researchers developed an 11-point numerical scale with five pictures representing youths at various levels of exertion while lifting weights. 26 children (M age 10.1 +/- 1.2 yr.) performed one set of 10 repetitions at 35%, 55%, and 75% of their one-repetition maximum on the chest press and leg press exercises using child-size weight training machines. Scaling procedures for the perceptual anchors on the perceived exertion scale were based on one repetition maximum testing. Children could use this scale to translate into numbers their perceptions of physical exertion during upper and lower body resistance exercise. Perceived exertion distributed as a positive linear function of the percent of one repetition maximum on the chest press and leg press exercises (rs = .70 to .77), and perceived exertion increased significantly across all three exercise intensities on both exercises. These preliminary findings provide partial evidence for validation when this scale was used during resistance exercise with children. Additional validation regarding perceived exertion during resistance exercise with children is warranted.     

Comparison of selected perceptual variables for backpacks with internal and external frames

Differences in perceptions of comfort, exertion, balance, and heart rate were investigated with two types of backpack. Subjects were 20 male volunteers (M age = 24.3 yr., SD: 3.6, M height = 180.02 cm, SD: 8.0, and M weight = 86.46 kg, SD: 14.84). Following oral briefing and practice trials, each subject was fitted at random with either an internal- or external-frame backpack containing 18.2 kg. By random, cross-over design, subjects completed a 30-m simulated hiking trial consisting of 16 separate obstacles designed to resemble actual off-trail hiking. Trials were conducted in a controlled environment with the walking intensity regulated by a metronome. Upon completion of each trial, the subjects rated the experience on perceived comfort, balance and stability, and rating of perceived exertion. Heart rate was recorded immediately prior to and following each trial. Analysis yielded a significant difference only on rating of perceived exertion in favor of the internal-frame backpack. Under limited circumstances, these data suggest that both types of backpacks provide similar comfort and balance and stability; however, internal frames in backpacks may reduce perceived exertion during short, demanding hikes.     

Development of a metabolic equation for the NuStep recumbent stepper in older adults

The purpose of this study was to develop an accurate metabolic equation for estimating steady-state oxygen consumption (VO2) during submaximal NuStep exercise. Adults (N = 40; M age = 64.0 yr., SD = 6.5; M height = 170.1 cm, SD = 9.1; M weight = 85.7 kg, SD = 19.9) performed two randomized testing sessions. Each session consisted of six stages with combinations of four workloads (1, 3, 5, and 7) at 3 cadences (60, 80, and 100 steps/min.). Multiple regression analysis to predict steady-state VO2 from NuStep workload (W), NuStep steps/min., and subject body mass resulted in the following model (R2 = .73): Steady-state VO2 = 3.5 + 0.016 (W* steps/min.) + 0.092 (steps/min.) - 0.053 (weight). The standard error of the estimate and total error for the prediction of steady-state VO2 under all NuStep workload conditions were 2.3 mL/kg/min. and 2.4 mL/kg/ min., respectively. The standard error of the estimate and total error values are similar to those previously reported in the literature regarding the accuracy of metabolic equations for other exercise modalities. These findings support the use of the equation developed to predict steady-state VO2 for NuStep exercise in older adult clientele.     

Perceptual and physiological responses during exercise in cool and cold water

This investigation examined the interaction of exposure to cold water stress with both perceived exertion and thermal sensation during exercise. Eight male volunteers performed arm, leg, and combined arm and leg exercise for 45 min. in water at 20 and 26 degrees C. Exercise was performed at a low (n = 7) and a high (n = 8) intensity relative to the ergometer specific peak oxygen uptake (VO2 peak). In general, percent VO2 peak did not differ between types of exercise in either 20 or 26 degrees C water. During low intensity exercise when power output was matched across water temperatures (Tw), percent VO2 peak was greater in 20 degrees C water (52%) compared to 26 degrees C water (42%). Ratings of perceived exertion (RPE) did not differ between Tw. During high intensity exercise when percent VO2 peak was matched across Tw, RPE was lower during exercise in 20 degrees C compared to 26 degrees C. Multiple correlation analyses comparing both final RPE and thermal sensation (TS) with physiological and thermal measures were performed across type of exercise and Tw. RPE was moderately correlated with heart rate (r = 0.68) and ventilation (r = 0.61), whereas very slight relationships were established with TS (r = 0.16), skin and rectal temperatures (r = 0.10 and r = 0.20). TS was moderately correlated with skin and rectal temperatures (r = 0.64 and r = 0.73), whereas low correlations existed between TS and both heart rate (r = 0.32) and ventilation (r = -0.12). These data suggest that the change in oxygen uptake associated with exercise in cold water does not add to the over-all perception of exertion. This perception appears to be related to cardiopulmonary variables rather than thermal measures, whereas thermal sensation is related to thermal measures and not cardiopulmonary variables.     

Sex differences in static lifting strengths at full range exertion heights in a young Taiwanese sample

This study evaluated sex differences in static lifting strengths (LS) at various exertion heights. Healthy adult young men (n=50; M age=23.4 yr., SD=2.3) and women (n=50; M age=22.5 yr., SD=2.8) were used as participants, and their static lifting strengths were measured at various heights (10 to 150 cm, in increments of 10 cm). Repeated measures ANOVA indicated that the strength profiles were significantly different. When the exerting height was less than or equal to 80 cm, the strengths of women were approximately two-thirds that of the men. Participants adopted a nearly erect posture at above 80 cm, and the weakness of women's upper extremities and disadvantageous posture were directly reflected in reduced strength values relative to men. One potential implication is that, because of the relatively lower isometric lifting strength for young Taiwanese women, caution should be exercised in the weight limit when lifting heights above the hip level, especially when above the shoulder level.     

Fluctuating dynamics of perceived exertion in constant-power exercise

ObjectivesTo reveal and study the fluctuating dynamics of perceived exertion (PE) during constant-power exercise performed under different conditions (duration, intensity, and termination).DesignA pilot and two subsequent experimental studies were performed. The studies consisted of manipulating workload and measuring fluctuating perceived exertion dynamics throughout the cycling task.MethodsIn a pilot study Borg's rating of perceived exertion (RPE) was measured every 15 s in 2 groups of 9 participants each (using RPE 6-20 and CR10 scales, respectively) cycling at heavy intensity until volitional exhaustion. The percentage of participants alternating increased and decreased RPE values (fluctuating dynamics) was calculated. In 2 subsequent experiments PE changes (increase/decrease perceptions) were reported when occurring in 2 groups of 13 participants cycling at a moderate intensity for 30 and 60 min, respectively (Experiment 1), and in another group of 12 participants cycling at heavy intensity until volitional exhaustion (Experiment 2). The individual time series of “increase”/“decrease” reports were divided into 5 non-overlapping temporal windows, and the percentages of “PE increase” were calculated for each window.ResultsIn the pilot study 66.6% (RPE 6-20 group) and 33.3% (CR10 group) of the participants showed an RPE fluctuating dynamics during the exercise. However, all participants showed a clear PE fluctuating dynamics during the moderate and heavy intensity exercises performed in Experiment 1 and Experiment 2, respectively. Nevertheless, a transition towards a PE non-fluctuating dynamics (dominated by “PE increase” reports) was noticed in Experiment 2 while approaching volitional exhaustion.ConclusionsPE seems to have a dominant fluctuating dynamics during constant-power cycling performed under different conditions (duration, intensity, and termination) that changes towards a non-fluctuating dynamics when approaching the volitional exhaustion point.     

Men's and women's perceptions of effort during progressive-resistance strength training

Previously sedentary adult men (M age=34.3 yr.) and women (M age =41.8 yr.) participated in a 25-wk., 7-station circuit-training program designed to evaluate the effects of a low-volume (1 set) and a high-volume (3 set) exercise regimen on the development of muscular strength. Participants completed the Borg scale of perceived exertion immediately following a chest-press exercise and a leg-extention exercise. Neither exercise volume nor sex classification was related to participants' ratings of exertion; however, exertion ratings for both exercises increased over the course of training.     

Relationship between ratings of perceived exertion and exercise-induced decrease in state anxiety

24 females (aged 18 to 28 yr.) completed two 24-min., randomly ordered bicycle ergometer exercise bouts at workloads maintaining steady state at 30% and 60% heart-rate reserve. Ratings of perceived exertion (RPE) were recorded at 3-min. intervals from Minutes 9 to 24 of exercise. State anxiety was measured prior to, immediately following and 50 min, after cessation of exercise. Regression analysis indicated no relationship between RPE and the pre- to postexercise changes in state anxiety.     

Effects of steady-state exercise on perceived pain: comparison of sedentary students and cyclists

In this study, the effect of fitness level on perceived pain before and after a steady state exercise was investigated. Ten trained cyclists (M age=25.2 yr., SD=4.9) and 10 sedentary men (Mage=24.5 yr., SD=2.2) performed a maximal graded test on a cycle ergometer. At least 48 hr. later the participants of both groups performed a 30-min. steady-state cycling test at 75% of VO2 max. Before the steady-state exercise and 5- and 30-min. postexercise, a pressure pain stimulation test was applied on the finger of each participant. Perceived pain was measured with Borg's CR10 scale at the end of each pain stimulation. The results indicated no significant changes in perceived pain between the pre-exercise and 5- and 30-min. postexercise values (effect sizes=.07 and .19, respectively). Moreover, no significant difference in perceived pain was found between the groups for pre-exercise (ES=.02) and 5- and 30-min. postexercise (ES=.16 and .21, respectively) values. These results do not confirm the analgesic effects usually observed after steady state exercise. Therefore, it is not possible to compare the analgesic effect of this exercise mode between participants characterized by different fitness levels.     

Decreased activation in the primary motor cortex area during middle-intensity hand grip exercise to exhaustion in athlete and nonathlete participants

It remains unclear whether activation kinetics in the motor cortex area is affected by training. The purpose of the present study was to examine the effect of training on the motor cortex activation. To accomplish this, the correlation between maximal voluntary contraction and motor cortex (M1) activity was examined. Differences in the motor cortex activation between two groups during exercise were examined in 14 male volunteer participants (M age 25.2 yr., SD = 1.4): seven highly trained athletes (VO2max = 60 ml/kg/min.; maximal voluntary contraction > 55 kg, M MVC = 63.6 kg, SD = 4.2) and seven nonathletes (VO2max < 45 ml/ kg/min.; MVC < 50.0 kg, M MVC = 4 3.5 kg, SD = 5.2). Participants were familiarized with the study protocol during which they performed a maximal voluntary static handgrip test. Specifically, M1 activation was measured by near-infrared spectroscopy throughout a handgrip exercise in which participants performed a sustained middle-intensity handgrip exercise (50% of maximal voluntary contraction) until voluntary exhaustion. In the Athlete group, activation in the M1 at voluntary exhaustion fell below the resting value. In the Nonathlete group, activation in the M1 was elevated throughout the exercise. Results suggest that motor signals from the motor cortex area correlate with exercise training status, especially during fatiguing exercise.     

A field study of step-up exercises with touch for elderly people

This study assessed step-up exercises appropriate for elderly persons (M age=70.7 yr., SD=7.0). The group did several exercises in 7 sessions per month (average participants per session was 14, SD=3). A 30-sec. chair-stand test (sit-to-stand), questionnaires on activities of daily living, and impressions of the exercises were examined. Activities of daily living were expected to differ on cluster analysis before and after exercise sessions. Each cluster was classified by basic and instrumental activities. The 30-sec. chair-stand test did not significantly improve. Subjects enjoyed doing exercises with touch. Appropriate exercises for elderly persons should promote activities of daily living. Functional movements with touch seem appropriate for maintaining physical fitness and social interaction.     

The effect of choice of exercise mode on psychological responses

Objectives: Choice has been linked to both motivation and psychological responses to exercise. This paper investigates participants’ psychological responses when they completed an exercise session where there was a high-preference exercise mode as opposed to a low-preference exercise mode. High- and low-preference were established by participants indicating their preferred choice of exercise from three standard modes used for aerobic work.Method: Participants were 20 low-active adults who exercised for 20 min on each mode of exercise (high-preference versus low-preference). Affect, ratings of perceived exertion (RPE) and heart rate (HR) were recorded every 5 min during exercise, and affect and HR were assessed pre-exercise and 5 min post-exercise.Results: Repeated measures analysis of variance revealed condition and time main effects for affect sub-scales and RPE and a time main effect for HR. Affect sub-scales, RPE and HR generally increased over time. RPE, Fatigue and Psychological Distress were higher in the low-preference condition and positive well-being was higher in the high-preference condition.Conclusions: Affect and RPE were influenced by the preferred choice manipulation. Affect was more positive, and RPE lower, in the high-preference versus low-preference condition while work rate remained constant across conditions.     

A normative zone of RPE ratings for use during graded exercise testing

The purposes of this investigation were to identify a zone of normality for ratings of perceived exertion (RPE) and to compare the RPE responses in patients with coronary artery disease to this zone. The zone was generated from RPE estimated during the last minute of each stage of a Bruce treadmill test in 44 normal adult men. RPE were regressed against the corresponding MET level for each exercise stage. The zone was established as the 95% confidence interval (CI) spanning the average RPE vs MET regression line. RPE estimated during the last 1.0 min. of a Bruce or Modified Balke treadmill test administered to adult men (n=37) with coronary artery disease were compared to the 95% CI zone. A total of 19 (51%) of the coronary artery disease patients estimated RPE during a progressively incremented treadmill test that were above the zone, indicating a comparatively greater than normal perception of strain for a given metabolic stress. The presently generated zone provides a practical use of RPE in the interpretation of clinical exercise tests.