Perceived exertion of physical effort for various manual handling tasks

Ten trained male students between 18 and 28 years of age participated in a study, designed to determine the relationship between perceived exertion and physiological costs of exertion during various manual lifting and lowering tasks. Perceived exertion was defined as one's subjective rating of the intensity of work being performed. Five subjects performed lifting tasks and another five performed lowering tasks. Weight of load lifted or lowered (6.8, 13.6, 20.5 kg), frequency of lift or lower (3, 6, 9 times/min), height of lift or lower (floor to 76 cm, 76 to 127 cm, floor to 127 cm), box width (38, 66 cm), box length (38, 66 cm) and angle of twist of the body (0 degree, 90 degrees) were the independent variables studied. Heart rate, oxygen consumption, and ratings of perceived exertion (RPE) were the response measures. RPE was found almost linearly related to heart rate and oxygen consumption when lifting or lowering loads. For lifting tasks, the coefficient of correlation between RPE and heart rate was 0.673. In the case of lowering tasks, this coefficient was 0.604. When oxygen consumption was considered, the corresponding coefficients for lifting and lowering were 0.734 and 0.619, respectively. The correlation of RPE with the physiological response variables indicates that the severity of manual materials handling tasks in industry can be evaluated quickly and inexpensively by using perceived exertion ratings (RPE).     

Validation of the intensity of walking for pleasure in obese adults

BACKGROUND: Despite evidence that 'walking for pleasure' represents the most common leisure-time physical activity, the exercise intensity associated with 'walking for pleasure' in the obese has not been established. METHODS: Heart rate (HR), perceived exertion (RPE) and walking speed were assessed for 30 obese and 20 non-obese adults as they completed two 2 km-walk tests on alternate days and were compared with a third 2 km walk with subjects walking 'as fast as possible'. RESULTS: Despite both obese (O) and non-obese (NO) groups rating the intensity of 'walking for pleasure' as 'light', HR and RPE data for only the NO group complied with definitions of 'light' intensity effort. 'Walking for pleasure' was characterised by a higher absolute (15 bpm, P < 0.05) and relative (70% of predicted maximum, P < 0.01) HR in the O group, which was representative of the transition between 'moderate' and 'hard' intensity exercise. The findings in the third, maximal trial were comparable across groups for all variables. CONCLUSION: Adiposity exerts a relative elevation-of-intensity effect on the cardiovascular system at walking speeds consistent with 'walking for pleasure'. 'Walking for pleasure' is sufficient to improve cardiovascular fitness in obese, but not normal-weight, individuals.     

Caffeine does not alter RPE or pain perception during intense exercise in active women

Attenuated perceptions of exertion and leg pain are typically reported during exercise with caffeine ingestion, yet these responses are relatively unexplored in women. The primary aim of this study was to assess the effect of caffeine on rating of perceived exertion (RPE) and pain perception during a simulated time trial. Ten active women (age=22.1±1.9yr) completed an 8.2km "all out" time trial on each of 3days separated by at least 48h. Initially, a practice trial was completed, and participants refrained from products containing caffeine and lower-body exercise for 24h prior to subsequent trials. During exercise, heart rate (HR), RPE, and leg pain were recorded. Using a double-blind, randomized crossover design, participants ingested anhydrous caffeine and glucose (each 6mg/kg bw+each 6mg/kg bw glucose) or placebo (each 6mg/kg bw of glucose) 1h pre-exercise. Despite not altering (P>0.05) RPE, HR, or leg pain, caffeine improved (P<0.05) cycling performance (17.7±1.0min versus 18.2±1.1min) and power output (121.6±17.5W versus 114.9±17.9W) versus placebo. Caffeine's ergogenic effects may be independent of changes in RPE or leg pain in active women performing a simulated time trial.     

Perceived exertion and heart rate models for estimating metabolic workload in elite British soldiers performing a backpack load-carriage task

Identifying field measures to estimate backpack load-carriage work intensity in elite soldiers is of interest to the military. This study developed rating of perceived exertion (RPE) and heart rate models to define metabolic workload for a backpack load-carriage task valid for a population of elite soldiers using serial data. Male soldiers (n = 18) from the British Parachute or Special Air Service Regiment completed an incremental treadmill walking and (or) running protocol while carrying a 20-kg backpack. Heart rate, RPE, and oxygen uptake were recorded at each incremental stage of the protocol. Linear mixed models were used to model the RPE and heart rate data in the metric of measured peak oxygen uptake. Workload was accurately estimated using RPE alone (SE = 6.03), percentage of estimated maximum heart rate (%E-MHR) (SE = 6.9), and percentage of measured maximum heart rate (%M-MHR) (SE = 4.9). Combining RPE and %E-MHR resulted in a field measure with an accuracy (SE = 4.9) equivalent to the %M-MHR model. We conclude that RPE, %E-MHR, and %M-MHR provide accurate field-based proxy measures of metabolic workload in elite British soldiers performing a backpack load-carriage task. The model is accurate for the metabolic range measured by these serial data for the backpack load-carriage task.     

A feasibility study comparing objective and subjective field-based physical exposure measurements during apple harvesting with ladders and mobile platforms

Although mobile orchardplatforms have been developed to improve apple harvesting productivity in the US, the physical exposures of workers usingthe mobile platforms have not been well characterized, partlydue to the lack of assessment tools specific to the tree fruitorchard environment. The purpose of this study was to evaluate the feasibility and utility of different subjective and objective methods for characterizing apple harvesting workers’ posture, armrepetition, heart rate, and perceived exertion during platform- and conventional ladder-based harvesting. During a regular full shiftwork (8 hours), the objective physical exposure measures (armelevation, torso inclination, and heart rate) of 6 platform, 6 ground, and 8 ladder workers were measured with tri-axial accelerometersand heart rate monitor; and subjective perceived exertion wascollected using standardized Borg RPE and CR-10 scales, translated into Spanish. The results showed that the arm elevation, torso forward bending, repetitiveness, heart rates, and perceived exertions were lower for the platform-based workers than forthe ladder-based workers. The subjective measures (Borg RPE and Borg CR-10) appeared to be similar and mirror the general trends of the objective heart rate and posture measures.These results indicate the potential benefit of these low-cost subjective measures when direct measurements are too costly,complicated, or not permitted. This study determined that field measurements of objective and subjective physical exposures were feasible for evaluating apple harvesting work. In summary, all themethods used appear to be feasible for field use in orchard-based environments..     

The effects of caffeine in women during aerobic-dance bench stepping

People of all ages and fitness levels participate regularly in aerobic-dance bench stepping (ADBS) to increase fitness and control body weight. Any reasonable method for enhancing the experience or effectiveness of ADBS would be beneficial. This study examined the acute effects of a single dose of caffeine on physiological responses during ADBS in women. When compared with a placebo, neither a 3- nor a 6-mg/kg dose of caffeine altered physiological responses or rating of perceived exertion (RPE) in 20 women (age 19-28 y) of average fitness level, not habituated to caffeine, while they performed an ADBS routine. Since neither dose of caffeine had any effect on VO2, VCO2, minute ventilation, respiratory-exchange ratio, rate of energy expenditure, heart rate, or RPE during ADBS exercise, it would not be prudent for a group exercise leader to recommend caffeine to increase energy cost or decrease perception of effort in an ADBS session. Furthermore, caffeine ingestion should not interfere with monitoring intensity using heart rate or RPE during ADBS.     

Effect of caffeine intake on pain perception during high-intensity exercise

Caffeine has been shown to reduce leg-muscle pain during submaximal cycle ergometry, as well as in response to eccentric exercise. However, less is known about its analgesic properties during non-steady-state, high-intensity exercise. The primary aim of this study was to examine the effect of 2 doses of caffeine on leg pain and rating of perceived exertion (RPE) during repeated bouts of high-intensity exercise. Fifteen active men (age 26.4 ± 3.9 yr) completed 2 bouts of 40 repetitions of "all-out" knee extension and flexion of the dominant leg at a contraction velocity equal to 180°/s. Before each trial, subjects abstained from caffeine intake and intense exercise for 48 hr. Over 3 days separated by 48 hr, subjects ingested 1 of 3 treatments (5 mg/kg or 2 mg/kg of anhydrous caffeine or placebo) in a randomized, single-blind, counterbalanced, crossover design. Leg-muscle pain and RPE were assessed during and after exercise using established categorical scales. Across all treatments, pain perception was significantly increased (p < .05) during exercise, as well as from Bout 1 to 2, yet there was no effect (p > .05) of caffeine on pain perception or RPE. Various measures of muscle function were improved (p < .05) with a 5-mg/kg caffeine dose vs. the other treatments. In the 5-mg/kg trial, it is plausible that subjects were able to perform better with similar levels of pain perception and exertion.     

Effect of potassium phosphate supplementation on perceptual and physiological responses to maximal graded exercise

This investigation evaluated the effect of oral potassium phosphate supplementation on ratings of perceived exertion (RPE) and physiological responses during maximal graded exercise tests (GXT). Eight highly trained endurance runners completed a GXT to anchor the Borg 15-point RPE scale and two double-blind counterbalanced GXTs. Subjects ingested either 4,000 mg x day(-1) of phosphate (PHOS) or a placebo (PLA) for 2 days. Two weeks separated GXTs. Phosphate levels obtained immediately prior to the GXTs were greater in PHOS than PLA. No differences between PHOS and PLA were noted for the submaximal and maximal physiological responses. RPE for the overall body were lower during PHOS than PLA at intensities corresponding to 70-80% of VO2max. This suggests that oral potassium phosphate supplementation mediates perceived exertion during moderately intense exercise.     

Exercise metabolism during moderate-intensity exercise in children with cystic fibrosis following heavy-intensity exercise

Muscle metabolism is increased following exercise in healthy individuals, affecting exercise metabolism during subsequent physical work. We hypothesized that following heavy-intensity exercise (HIE), disease factors in children with cystic fibrosis (CF) would further exacerbate exercise metabolism and perceived exertion during subsequent exercise. Nineteen children with CF (age, 13.4 ± 3.1 years; 10 female) and 19 healthy controls (age, 13.8 ± 3.5 years; 10 female) performed 10 bouts of HIE interspersed with 1 min of recovery between each bout. Three minutes later participants completed a 10-min moderate-intensity exercise (MIE) test (test 1). The MIE test was subsequently repeated 1 h (test 2) and 24 h (test 3) later. Each MIE test was identical and participants exercised at individualized work rates, calibrated by an initial graded maximal cardiopulmonary exercise test, while metabolic and perceived exertion measurements were taken. Following HIE, mixed-model ANOVAs showed a significant difference in oxygen uptake (VO?) and rating of perceived exertion (RPE) between the 2 groups across the MIE tests (p < 0.01). In controls, VO? (L·min?1) and RPE decreased significantly from test 1 to test 2 (p < 0.01) and test 2 to test 3 (p < 0.05). However, in children with CF, VO? (L·min?1) increased significantly from test 1 to test 2 (p < 0.01), while RPE did not differ, both VO? and RPE decreased significantly from test 2 to test 3 (p < 0.01). In conclusion, following HIE the metabolic and perceptual responses to MIE in both groups decreased 24 h later during test 3. These data show that children with mild-to-moderate CF have the capability to perform HIE and 24 h allows sufficient time for recovery.     

Occlusion of sight,sound and smell during Green Exercise influences mood,perceived exertion and heart rate

This study’s aim was to identify the relative contribution of sight, sound and smell to the Green Exercise effect. It was hypothesised that visual occlusion while exercising in a natural environment would have the greatest diminishing effect on perceived exertion and mood compared to auditory and olfactory occlusion. Twenty-nine healthy participants were randomly assigned to one of the three groups: visual (n = 10), auditory (n = 9) and olfactory occlusion (n = 10). Each performed six, 5-min bouts of exercise alternating between full sensory and occlusion. Rate of perceived exertion (RPE), heart rate (HR) and mood were recorded at the end of each bout. Sensory-occlusion increased mood, RPE and HR; effects were strongest when sounds were blocked but virtually absent when vision was blocked. During sensory occlusion, mood changes were characterised by increased Fatigue and Confusion, and reduced Vigour. Reductions in Tension and Vigour and increases in Fatigue were found during full sensory exercise, consistent with previous research findings.     

Resuming Domestic Activities After Myocardial Infarction: A Study in Female Patients

For patients who have recently had a myocardial infarction (MI), domestic activities may demand a considerable and potentially hazardous amount of effort. The aim of this study was to analyse the cardiovascular load due to common household tasks. A method for measuring the workload of six standardized domestic activities was developed and tested in six healthy volunteers. The method was then used on 21 women who had had a recent MI. The women performed the test at their usual working pace. Heart rates and Borg rates of perceived exertion during these activities were compared with the values obtained at exercise testing (ET) on a bicycle ergometer before discharge from hospital after the acute MI and at a maximal ET 6 weeks after discharge. The results of a maximal ET in 16 women with non-recent coronary events were used as reference values. It was shown that resumption of common domestic work after a recent MI is indeed physically demanding. In 9 of the 21 patients, heart rates during domestic work, especially static-dynamic work (e.g. carrying shopping bags or wet laundry), exceeded the peak level allowed at the pre-discharge ET. Patients tended to underestimate the exertion required for domestic work compared with the workload ratings at similar heart rates during the pre-discharge ET. We suggest that female post-MI patients without signs of moderate/severe heart failure or significant myocardial ischaemia at a pre-discharge ET can resume domestic work, but that they should be cautious about doing strenuous static-dynamic work during the first 6 weeks after homecoming.     

Reentrainment of diurnal variation of psychological and physiological performance at the end of a slowly rotated shift system in hospital workers

Summary Eighteen normal male nurses were tested on a battery of simple psychomotor tasks, subjective self-ratings and physiological tests on three weekly occasions, during the 6th day of each shift (morning, afternoon, night) of their actual job rotation pattern.The shift order was assigned according to a fully balanced design and the tests were carried out between the 3rd and the 5th h from the beginning of work (approximately at 10 a.m., 6 p.m., and 2 a.m.). During the night shift, the subjects rated themselves as most tired and reported higher perceived exertion at different work loads performed on a bicycle ergometer. None of the psychological and physiological variables showed significant inter-shift differences except heart rate and blood pressure: both were lower in the night, the former only at rest and after a light effort, the latter only under hardest work loads. A very high correlation was found between perceived exertion and heart rate in all three shift conditions while a negative correlation between perceived exertion and extraversion emerged in the night occasion only. The present results are discussed and the hypothesis of an adaptation of performance, on most of the tests used, to this weekly rotating shift system is suggested.Paper presented at the 4th International Symposium on Night and Shift Work, Dortmund, 14–17 November 1977     

Functional Capacity Evaluations in Persons with Spinal Disorders: Predicting Poor Outcomes on the Functional Assessment Screening Test (FAST)

This study determines how performance on the simple, low exertion Functional Assessment Screening Test (FAST) relates to performance on more extensive physical and psychological testing. One hundred eighty-eight persons with chronic back disability and 17 spine healthy volunteers underwent the FAST (three 2-min static tests [kneeling, stooping, and squatting] and two 5-min tests [repetitive stooping and repetitive twisting while standing]), the Progressive Isoinertial Lifting Evaluation (PILE), trunk extension endurance, submaximal bicycle ergometry, and psychological profiles. All FAST components were completed by 88% of spine healthy subjects, but only by 19.7% (n = 37) of the back patients. Internal consistency for overall test performance was 0.82 (alpha coefficient). Back pain noncompleters had poorer performance on the PILE and trunk extension endurance despite similar cardiovascular fitness and perceived exertion during testing. They had more dysfunctional coping mechanisms, pain avoidance, depression, and self-reported disability. Since performance on nonstrenuous testing is so poor, and psychosocial variables relate strongly to test performance, extensive Functional Capacity Evaluations may not be necessary or valid in assessing the physical performance of this population of chronic back pain patients.     

Psychosocial Factors and Functional Capacity Evaluation Among Persons with Chronic Pain

Psychosocial factors have been found to have a significant impact on functional activity, particularly among persons with chronic pain. While various systems have been developed to assess functional limitations through functional capacity evaluation (FCE), assessment of psychosocial factors that may impact function have been largely ignored. This paper examines the existing literature on psychosocial factors and FCE performance. Given that there are few studies that have directly addressed this issue, the paper also examines psychosocial factors that have been found to influence function in persons with pain. The results of the literature review indicate that few psychosocial factors have been found to be directly associated with FCE and functional measures, although many are related to various measures of disability. The strongest evidence that psychosocial factors are related to functional performance is based on the studies examining the association between functional activity and pain-related fear, self-efficacy, and illness behavior. Psychosocial factors have also been shown to influence measures of sincerity of effort often obtained during FCE. Proposals for modifying FCE assessment are given based on the available data, as well as suggestions for future research.     

Affective outcomes during and after high-intensity exercise in outdoor green and indoor gym settings

Outdoor exercise settings promote greater psychological well-being than synthetic equivalents, although the influence of the exercise context has not been investigated at high exercise intensities. This study compared the psychological effects of high-intensity exercise in outdoor green and indoor gym settings in 22 adult runners using a randomized repeated measures design. Affect and perceived exertion were assessed before, during, and after a 6000-m run with the second half completed at maximum effort. Perceived exertion and activation increased in a progressive manner from baseline to 6000 m, and decreased during the 10-min recovery post-run. Non-significant reductions in affective valence were observed between 3000 and 6000 m, followed by a significant increase post-run. Outcomes did not differ at any time point between the settings. This study suggested that regular runners experience positive affective responses during and after high-intensity exercise in both a natural outdoor environment and an indoor gym.     

Effects of purified oxygenated water on exercise performance during acute hypoxic exposure

The purpose of this study was to assess the effects of purified oxygenated water on exercise performance under hypoxic conditions. Nine recreational male cyclists (age = 26.6 +/- 5.2 y, weight = 87.6 +/- 19.5 kg, VO2peak = 46.5 +/- 5.9 mL x kg(-1) x min(-1)) completed two 600 kJ cycling time trials under hypoxic conditions (FIO2 = 13.6% O2, Pbar = 641 mmHg) separated by 2 wk. Trials were completed following 3 d ingestion of 35 mL x kg(-1) x d(-1) of control (CON) or experimental (EXP) water. Time to completion, heart rate (HR), rate of perceived exertion (RPE), pulse oximetry (SaO2), blood gases (PcO2 and PcCO2), and lactate were measured during the trials. Hydration was assessed with pre- and post-exercise body weight and 24-h urine specific gravity. Performance, hydration, and blood oxygenation were unaffected by EXP water. Results of this study suggest that purified oxygenated water does not improve exercise performance in moderately active males.     

Maximum acceptable weight of manual load carriage for young Taiwanese males

This study examined the maximum acceptable weight of carriage (MAWC) for young Taiwanese males experienced in manual load carriage tasks. The elements of the examined load carriage tasks included lifting a box from the floor to the waist height, turning around while holding the box, carrying the box at the waist height for a distance, lowering the box to the floor, turning around, and walking unloaded back to the original position. Subjects performed the load carriage tasks over different levels of carriage distance, frequency, box width (sagittal dimension), and handle according to a response surface design. The results showed that subjects' MAWC decreased with carriage distance, frequency and box width, while heart rate and rate of perceived exertion (RPE) increased with carriage distance, frequency and box width. The MAWC for box with handles was on average 1.5 kg more than that for box without handles, while the effects of handle on heart rate and RPE were very trivial.     

Female work capacity during the menstrual cycle: physiological and psychological reactions.

Changes in physical and mental work capacity during the menstrual cycle were studied in 12 healthy woemen with severe menstrual distress. Physiological and psychological tests were performed before, during, and after menstruation. Heart rate, pulmonary ventilation, oxygen uptake, blood lactate concentration, and perceived exertion were measured during work on a bicycle ergometer ar two submaximal work loads corresponding to 40 and 70 %, respectively, of individual maximal oxygen uptake. Mental work capacity was studied with the aid of performance tests of psychological functions such as attention, short-term memory, perceptual speed, perception of time, and reaction time. No change in heart rate or oxygen uptake could be observed over the three phases of the menstrual cycle. However, pulmonary ventilation during work varied significantly. It was highest in the menstrual phase. At the same heart rate exercise on the bicycle ergometer was perceived as more exerting in the menstrual phase than in either the premenstrual or postmenstrual phase. Among the performance tests significant results were obtained only in a test of reaction time, which was slightly impaired during the menstrual phase. The results of the performance tests do not however support the assumption that menstruation affects a woman's mental work capacity.     

人体体能快速恢复装置效果评价

目的 评价"人体体能快速恢复装置"对促进官兵大强度军事训练后体能恢复效果,为进一步推广应用提供依据.方法 受试对象为96名官兵,随机分为试验组(运动后即刻使用该装置)和对照组(运动后不使用该装置)各48人,2组在进行大强度运动后同时检测以人体体征为主的指标.结果 在30 min内试验组心率[(76.4±10.0)次/m...