Subjective Perception Of Exertion Research Articles

Exercise intensity at RPE13 in female Kendo practitioners

Abstract: Introduction: Kendo, a Japanese martial art, requires rigorous physical and mental training. Kendo practitioners who engage in daily mental training may experience a disparity between their subjective perception of exertion and the actual physiological load on their bodies. Methods: Fifteen healthy adult female kendo practitioners were recruited as participants. Participants were asked to report levels of exertion using the Ratings of Perceived Exertion (RPE) during a progressive, load-incremented stress test. The participants’ heart rate at the time of reporting RPE13, which is considered a “somewhat hard” level of exertion, as well as heart rate at the anaerobic threshold (AT) to measure actual load, were compared to the maximum heart rate measurement obtained during the test. Results: The participants’ heart rates at RPE13 were found to be higher than those at AT, based on their values as percentages of maximum heart rates. Conclusion: This study discovered that kendo practitioners engaged in regular mental training exhibited a higher heart rate at “somewhat hard” exertion (RPE13) compared to the anaerobic threshold (AT), indicating a relative increase in RPE. Additional research is necessary to determine if this effect is attributable to mental training.

Inspiratory muscles pre-activation in young swimmers submitted to a tethered swimming test: effects on mechanical, physiological, and skin temperature parameters

Inspiratory muscles pre-activation (IMPA) has been studied to improve subsequent performance in swimming. However, the effects of IMPA on various parameters in swimmers are still unknown. Therefore, this study aimed to investigate the effects of IMPA on the mechanical parameters, physiological responses, and their possible correlations with swimming performance. A total of 14 young swimmers (aged 16 ± 0 years) underwent a 30-s all-out tethered swimming test, preceded or not by IMPA, a load of 40% of the maximal inspiratory pressure (MIP), and with a volume of 2 sets of 15 repetitions. The mechanical (strength, impulse, and fatigue index) and physiological parameters (skin temperature and lactatemia) and the assessment of perceived exertion and dyspnea were monitored in both protocols. The IMPA used did not increase the swimming force, and skin temperature, decrease blood lactate concentration, or subjective perception of exertion and dyspnea after the high-intensity tethered swimming exercises. Positive correlations were found between mean force and blood lactate (without IMPA: r = 0.62, P = 0.02; with IMPA: r = 0.65, P = 0.01). The impulse was positively correlated with blood lactate (without IMPA: r = 0.71, P < 0.01; with IMPA: r = 0.56, P = 0.03). Our results suggest that new IMPA protocols, possibly with increased volume, should be developed in order to improve the performance of young swimmers.

RESPOSTAS FISIOLÓGICAS E PSICOAFETIVAS DE ADULTOS TREINADOS EM PROTOCOLOS AGUDOS DE HIIT

ABSTRACT High Intensity Interval Training (HIIT) promotes similar adaptations and in some cases, superior to continuous aerobic training of moderate intensity, even when performed at all-out intensities. In this condition, it tends to have the greatest physiological disturbance and accumulation of metabolites compared to submaximal intensities, being one of the main factors associated with the negative response of pleasure in training. Objective: To verify the relationship between physiological and psychophysiological responses in order to repeat the training of two HIIT protocols of mesm volume load and different periods of work in trained adults of both sexes. Methods: In a randomized experiment, the sample consisted of 9 individuals aged 28±5 years, body mass 69.6±14.2 kg, height 169±0.1cm, BMI 24.1±2.3 kg/m2 and body fat percentage 20.2±7.9% practitioners of structured aerobic physical exercises for at least six months. Two different HIIT protocols were performed on an exercise bike, being (I) protocol 1:0.5, with prescribed intensity (80-90% of MAX HR), (II) protocol 1:2 with prescribed intensity (all-out) with total duration of effort of 20 minutes and interval of at least 48 hours between each session. Heart rate (HR), systemic blood pressure (SBP), subjective perception of exertion (SPE), visual analog scale (VAS), affective response (AR), fun (PACES) and intention to repeat the session were analyzed. The statistical analysis used was ANOVA with Tukey's post-hoc (p&lt;0.05). Results: The analyses of HR, SBP, VAS, PACES and SPE showed no significant difference between the training protocols. The affective response (AR and intention to repeat) showed a decline in the protocol 1:0.5, but without significance (p&gt;0.05). Conclusion: The data allow us to conclude that the 1:2 protocol caused greater physiological disturbances during exertion and presented greater positive affective response and intention to repeat the exercise session, variables that may contribute to adherence to regular physical exercise. Level of Evidence I; Therapeutic studies - Investigation of treatment results.

IMPACTS OF PHYSICAL EXERCISE ON POST-COVID-19 SEQUELAE IN PATIENTS TREATED AT ACADEMY CLINIC SCHOOL OF PHYSICAL EDUCATION

The COVID-19 pandemic has had a significant impact on global health, with patientsexperiencing post-infection sequelae such as dyspnea, chronic fatigue, body aches andmemory loss. This study aims to investigate the effectiveness of a physical exercise programin improving these symptoms. The database analyzed was from the Clinica e Academiaschool of physical education at the State University of the Midwest, which receives patientsrecovering from these symptoms. A structured anamnesis was performed, in which patientsreported pre- and post-COVID-19 conditions. Four variables were investigated: dyspnea,chronic fatigue, body aches and memory loss. Training consisted of resistance and aerobicexercises, twice a week, monitored by heart rate and subjective perception of exertion, withworkload progressing whenever possible. Each patient received a prescription based on theAmerican College for Prescription of Exercise for Health guidelines. There was a decrease inchronic fatigue (57.1% to 28.6%), dyspnea (50% to 21.4%), body aches (35.7% to 7.1%) andmemory loss (35.7% to 28.6%). These findings suggest that the implementation of physicalexercises can attenuate post-covid19 symptoms. However, this descriptive study is notconclusive and well-designed essays that can better elucidate the subject are recommended.

Photobiomodulation Therapy Combined with a Static Magnetic Field Applied in Different Moments Enhances Performance and Accelerates Muscle Recovery in CrossFit® Athletes: A Randomized, Triple-Blind, Placebo-Controlled Crossover Trial

The ergogenic effects of photobiomodulation therapy combined with a static magnetic field (PBMT-sMF) on exercises with characteristics similar to those of CrossFit® are unknown. This study was aimed at investigating the effects of PBMT-sMF applied at different times on recovery and physical performance in CrossFit® athletes by analyzing functional aspects, muscle damage, inflammatory processes, and oxidative stress. This was a prospectively registered, triple-blinded, placebo-controlled, crossover trial. CrossFit® athletes were recruited and assigned to receive one of the four possible interventions. Each intervention included protocols before and after the exercise (referred to as the workout of the day (WOD)). The four possibilities of intervention were as follows: placebo before and after WOD (placebo), PBMT-sMF before and placebo after WOD (PBMT-sMF before), placebo before and PBMT-sMF after WOD (PBMT-sMF after), and PBMT-sMF before and after WOD (PBMT-sMF before and after). The order of possibilities for the interventions was randomized. The primary outcome was the functional test performance. The secondary outcomes were the subjective perception of exertion, muscle damage, inflammation, and oxidative stress. The outcomes were measured before the WOD; immediately after the intervention; and 1, 24, and 48 hours after the WOD. Statistical analysis was performed using repeated measures ANOVA followed by the Bonferroni post hoc test to examine the differences between the interventions at each time point. Twelve participants were randomized and analyzed for each sequence. PBMT-sMF enhanced the performance on functional tests (calculated as a percentage of change) when applied before or after WOD in the assessment performed immediately post-WOD and at 24 and 48 hours later (p < 0.05) compared to placebo and PBMT-sMF before and after WOD. In terms of the secondary outcomes, PBMT-sMF applied before or after WOD significantly decreased the creatine kinase, catalase, and superoxide dismutase activities and interleukin-6, thiobarbituric acid, and carbonylated protein levels (all p < 0.05) compared to the other possibilities of intervention. In addition, PBMT-sMF applied before and after WOD decreased creatine kinase activity at 24 hours and IL-6 levels at 24 and 48 hours compared to placebo (p < 0.05). None of the participants reported any adverse events. PBMT-sMF enhanced the performance of functional tests, decreased the levels of biochemical markers of muscle damage and inflammation, decreased oxidative stress, and increased antioxidant activity in CrossFit® athletes when applied before or after WOD.

English

The objective of the present study was to evaluate the effect of anthropometric variables and flexibility on the performance of women aged 55+ years on abdominal test protocols. The sample was composed by 20 physically active volunteers, aged 55 years (median 61), who were participants in gymnastic activities program. Each volunteer performed two abdominal tests: partial trunk flexion with a 7.6 cm sliding of the hands (P1) and partial flexion of the trunk with the hands on the thighs (P2), both executed with the feet resting on the ground. For analysis, the number of correct executions (final position) was considered in each test, as recommended by the authors. Measurements of body mass, flexibility, height, waist and hip perimeters, subjective perception of exertion, and calculations of body mass index and waist-hip ratio were performed. The perception of abdominal effort, and discomfort or pain in the cervical and lumbar region were also evaluated. The results showed that there were no statistically significant associations between the analyzed indicators (Age: P1: rs = -0.024, p = 0.916; P2: rs = -0.194, p = 0.407; BMI: P1: rs =-0.064, p = 0.792; P2: rs = -0.235, p= 0.327; Waist Circumference: P1: rs = -0.143, p = 0.563; P2: rs = 0.027, p = 0.908; Flexibility: r s= -0.327, p = 0.169; P2: rs = 0.0009, p = 0.991; Hip waist ratio: P1: rs = -0.209, p = 0.371; P2: rs = 0.217, p = 0.353) and the performance on the tests. In addition, 35% of the participants made valid attempts on P1 while 45% produced at least one valid attempt on P2. It was concluded that both abdominal tests were adequate for the studied sample and they can be applied to adult and elderly women to assess their abdominal musculature.

Effects of surgical face masks on exercise performance and perceived exertion of exercise in well-trained healthy boys

Mit dieser Studie wurden die Effekte chirurgischer MNS auf die körperliche Leistungsfähigkeit sowie das subjektive Belastungsempfinden bei trainierten elfjährigen Jungen untersucht.Im aeroben und aerob-anaeroben Übergangsbereich fand sich keine Verminderung der objektiven Leistungsparameter. Allerdings zeigte sich auf der maximalen Belastungsstufe mit MNS eine signifikante Verminderung der Laufzeit sowie eine signifikante Erhöhung des subjektiven Belastungsempfindens bei ansonsten unveränderten Leistungsparametern. Zusammenfassend beeinflusst die Verwendung chirurgischer „Alltags“-MNS bei Kindern die sportlichen Aktivitäten nicht, solange die Belastungen primär im aeroben Intensitätsbereich durchgeführt werden.

Reduced Dose of Beta-Alanine Is Sufficient to Maintain Performance in Repeated Sprints

Zandona, BA, Ramos, RA, de Oliveira, CdS, McAnulty, SR, Ferreira, LHB, Smolarek, AC, Enes, AAN, Urbinati, KMdSS, Aragon, AA, Schoenfeld, BJ, and de Souza Junior, TP. Reduced Dose of Beta-Alanine Is Sufficient to Maintain Performance in Repeated Sprints. J Strength Cond Res 36(6): 1636-1642, 2022-Beta-alanine (BA) supplementation has been shown to be effective in improving physical performance by increasing carnosine concentration. However, it is still necessary to know the effect of a maintenance dose on performance. Thus, this study aimed to investigate the effects of a maintenance dose of BA supplementation on performance. Forty-four anaerobically trained men with 23.9 ± 3.8 years of age, 176.0 ± 0.05 cm height, 81.2 ± 7.5 kg body mass, and 15.5 ± 2.9% of body fat performed a cycle ergometer test consisting of 4 sprints of 30 s with 4 minutes of active recovery. The study comprised 3 phases: (a) presupplementation, (b) supplementation with 6.4 g·d-1 BA or placebo, and (c) postsupplementation with a maintenance dose of 1.2 g·d-1 of BA or interruption of supplementation. Data were analyzed using generalized estimated equations with a priori 0.05 level of significance. The placebo group and interruption group presented a lower power (7.28 ± 0.66 and 7.71 ± 0.42 W·kg-1 vs. 8.04 ± 0.84 and 9.25 ± 1.18 W·kg-1, respectively; p < 0.05) during the third sprint in postsupplementation, whereas the maintenance group maintained the required power (7.47 ± 1.03 vs. 8.74 ± 1.07 W·kg-1; p > 0.05). The placebo group also presented higher percentage of fatigue (44.5% ± 12.3 and 44.8% ± 7.7 vs. 37.6 ± 7.2%; p = 0.021) and higher subjective perception of exertion (8.92 ± 0.90 vs. 8.00 ± 1.60; p = 0.028). Therefore, the maintenance dose of 1.2 g·d-1 BA was effective in maintaining performance, whereas a reduction in performance was observed after supplementation interruption.

Outdoor circuit test: construction and validation of an instrument for the prediction of cardiorespiratory capacity for older adults

Abstract Objective: the present study aimed to construct, validate and verify the reliability of a protocol for assessing the cardiorespiratory capacity of older adults attending the Rio ao Ar Livre (Open Air Rio, or RAL) project entitled the “Outdoor Circuit Test” (OCT). Method: validity and reliability tests were carried out to assess the accuracy of the OCT, with 50 older adults (70.6 ± 6.3 years) of both sexes who regularly attended the RAL. Validity was tested by collecting VO2max data under maximal cardiopulmonary exercise test conditions, and the OCT variables: a) Circuit Execution Time; b) Heart Rate; c) Subjective Perception of Exertion; d) Average Heart Rate (HRméd). Reliability was tested through the reproducibility of the measurements of the OCT variables, expressed by the Intraclass Correlation Coefficient (ICC). The predictive capacity of VO2max was given by multiple linear regression and the final stability of the model by the analysis of the residues and the calculation of Cook’s distances, with a value of P≤ 0.05 adopted for statistical significance. Results: the predictive model based on age, sex, waist circumference, BMI and circuit execution time explained 41% of VO2max variance, with a standard error of estimate of 18.5%. Conclusion: the OCT exhibited satisfactory reproducibility (0.62 to 0.93), and proved to be valid, reliable, and specific for predicting the cardiorespiratory fitness of older adults attending RAL, demonstrating adequate reproducibility and a positive association with the physical fitness of older adults.

Design and ergonomic assessment of an infusion set connector tool used in nursing work

Nursing is a physically demanding job characterized by a high prevalence of fatigue and musculoskeletal disorders. One of the high-exertion and repetitive nursing tasks is the manual connection of an infusion set to a medical fluid bottle. Such physical work can be eased by the design of new hand tools. Correspondingly, this study designed and ergonomically assessed an infusion set connector tool (ISCT) and compared it with that of manual connection. First, a prototype of ISCT was designed to perform infusion set connecting task in the mechanical form. Subsequently, 12 nurses were asked to connect an infusion set to medical bottle in the form of manual and mechanical tasks and these tasks were evaluated using ergonomic indices including muscular activity level, force, posture, and subjective (Borg scale CR10) measures. Results showed that the activity levels (root mean square) of the extensor digitorum communis, flexor carpi radialis, biceps, triceps, and deltoid muscles remarkably decreased when the nurses used the ISCT. The postures of the wrist, arm, and shoulder regions were corrected from Rapid Upper Limb Assessment action level 3 to 2 when the designed tool was used. Additionally, the subjective perception of exertion was significantly lower with the use of the prototype.

Immediate effect of scapula-focused exercises performed with kinematic biofeedback on scapular kinematics in individuals with subacromial pain syndrome

BackgroundGiven the changes in the patterns of muscular activation and scapular movement in individuals with subacromial pain syndrome, the use of neuromuscular training has been considered in rehabilitation protocols. There is currently no evidence of the effects of the use of three-dimensional (3D) kinematic biofeedback on individuals with subacromial pain syndrome. This study aimed to determine the immediate effect of scapular motor control exercises using 3D kinematic biofeedback on the scapular kinematics, inter-segment coordination and pain of individuals with subacromial pain syndrome. MethodThe kinematics of the scapulothoracic joint of 26 subjects with subacromial pain syndrome were assessed in the movement arm elevation and lowering in the sagittal plane before and after performance of three scapula-focused exercises using kinematic biofeedback. The individuals were familiarized with the selected exercises to acquire a greater scapular posterior tilt, while kinematic biofeedback, with visual and auditory stimuli, was used in real time. Scapular kinematics, pain, and subjective perception of exertion were the pre- and post-test measures. FindingsIn the movement of arm elevation and lowering, no differences were found in scapular tilt and on coordination between the segments pre- and post-test and the effect size was considered small. InterpretationOur results demonstrate that the performance of scapula-focused exercises using kinematic biofeedback does not cause immediate changes in the magnitude of scapular movement. However, inter-segmental coordination showed evidence of changes for scapular tilt in the lowering of the arm and internal rotation in the elevation and the lowering of the arm in individuals with subacromial pain syndrome.

Heart rate kinetics during exercise in patients with subclinical hypothyroidism.

Studies suggest that patients with subclinical hypothyroidism (SH) have sympathovagal imbalance, which could lead to a slower heart rate (HR) response in the transition from rest to exercise. Thus the objective of this study was to investigate the behavior of the HR kinetics in patients with SH during the transition from rest to exercise. The study included 18 SH women [thyroid stimulating hormone (TSH) = 6.95 ± 2.94 μIU/ml and free thyroxine (FT4) = 0.96 ± 0.15 ng/dl] and 17 euthyroid women (TSH = 2.28 ± 0.84 μIU/ml and FT4 = 0.98 ± 0.07 ng/dl). Both groups were matched for physical activity, menopausal status, and age. The HR kinetics was obtained during the course of a constant-load exercise (50 W), for 6 min, in a cycle ergometer, and quantified from the mean response time (MRT), which is equivalent to the time taken to reach 63% of the HR at steady state. SH patients showed slower HR kinetics than the control group (MRT = 48.5 ± 17.6 vs. 36.0 ± 10.3 s, P = 0.015). The MRT has been shown to correlate with the level of physical activity (r = -0.361; P = 0.033) and with the subjective perception of exertion at the end of the exercise (r = 0.365; P = 0.031). It is concluded that SH patients have slower HR kinetics in the transition from rest to exercise compared with euthyroid women, with this impairment being associated with lower levels of physical activity.NEW & NOTEWORTHY Subclinical hypothyroidism patients have slower heart rate kinetics in the transition from rest to exercise when performing a constant-load exercise at 50 W.

Validación del Special Judo Fitness Test con la técnica Tokui Waza. Estudio piloto

&lt;p class="CuerpoA"&gt;El objeto del presente estudio fue validar si la aplicación del Special Judo Fitness Test (SJFT) para judokas genera mejores resultados a través de su aplicación con el Tokui Waza (TW) del judoka (técnica especial), frente a la impuesta por el propio test, Ippon Seoi-Nage, en situaciones de ausencia de fatiga (AF) y de fatiga (CF). Se seleccionaron tres competidores de nivel nacional que realizaron los 4 SJFT repartidos en dos días alternos: un día el SJFT con su TW, en ambas situaciones (AF y CF); y a las 48 horas el SJFT estándar del mismo modo en ambas situaciones (AF y CF). Se registraron valores del test SJFT, la frecuencia cardiaca (FC), la concentración lactato sanguíneo [lact] y la percepción subjetiva de esfuerzo (RPE). Los judokas obtuvieron índices en el SJFT muy similares para ambos test en AF (12,41±0,21 frente a 12,52±0,89), sin embargo, en situación CF los valores de FC, [lact]y número de proyecciones fueron mejores en el SJFT-TW. &lt;/p&gt;

Zusammenhang zwischen RPE und Blutlaktatkonzentration im Krafttraining

Quantifying actual individual training intensity in resistance training is essential for athletes and trainers, but is at present only possible with methodological problems. Thus, the purpose of this article is to examine the relationship of different types of RPE (rating of perceived exertion) with blood lactate concentrations in hypertrophy training. Hereby it is possible, to deduce conclusions about the validity of the RPE-scale and different times of monitoring. In this article two studies with male subjects are presented (study 1: n=10, 23.7 ± 2.8 years; study 2: n=16, 24.9 ± 2.0 years). In both surveys, subjects had to complete 3 sets with 3 minutes of rest between sets in every exercise. Blood lactate was measured before each exercise and two minutes after the completion of each set. RPE was questioned in different forms simultaneous to lactate measurement as well as directly after each set. Results show medium correlations between subjective perception of exertion and blood lactate concentrations (mean r=0.55-0.71). RPE for the whole body (RPE-O) directly measured after the sets, showed the highest relationship with r=0.71. Maximum lactate values ranged from 4.59–15.22 mmol/l between the subjects. As a result, subjective perception of exertion seems to be parallel to blood lactate concentration on an individual basis. Here, the different forms of RPE-questioning have to be regarded individually. The large range of lactate values show a high individuality of lactate response, also influenced by the amount of muscle mass used. As a conclusion, quantifying individual training intensity should be only done in an individual, longitudinal setting with highly constant surrounding conditions. Although it remains unclear, if a discrete and valid diagnostic tool exists.

Comparação das variáveis fisiológicas no teste de caminhada de seis minutos e no teste da escada em portadores de doença pulmonar obstrutiva crônica

INTRODUÇÃO: A intolerância ao exercício prejudica a realização das atividades de vida diária em portadores de doença pulmonar obstrutiva crônica (DPOC) e a avaliação dessa limitação é fundamental. Objetivo: Comparar o teste de caminhada dos seis minutos (TC6') com o teste da escada (TE) em portadores de DPOC. MÉTODOS: Prospectivo composto por 21 pacientes portadores de DPOC avaliados para um programa de reabilitação pulmonar que realizaram o TC6' e o TE. As variáveis fisiológicas frequência cardíaca (FC) e saturação periférica de oxigênio (SpO2), além da escala de Borg modificada, foram aferidas antes e após cada teste. A distância percorrida era medida ao término de ambos os testes. RESULTADOS: Comparando os momentos (inicial versus final) das variáveis fisiológicas de ambos os testes, foi observado no TC6' (FC 81,1 ± 2,6 versus 98,4 ± 4,4; SpO2 94,9 ± 2,2 versus 90,4 ± 5,0; PSE Borg 0,5 ± 0,8 versus 3,6 ± 2,5) e no TE (FC 86,9 ± 18,8 versus 119,3 ± 14,5; SpO2 94,7 ± 2,5 versus 90,1 ± 4,5; PSE Borg 0,2 ± 0,4 versus 7,0 ± 2,3), sendo que todas as variações foram estatisticamente significativas (p &lt; 0,001) em ambos os testes. Quando avaliada a alteração das variáveis em ambos os testes, verificou-se que a SpO2 obteve redução semelhante (p = 0,912), a FC aumentou significativamente mais no TE (p = 0,006), bem como a PSE Borg (p &lt; 0,001). Em relação à distância percorrida, o TC6' permitiu que os participantes percorressem uma distância significativamente maior do que o TE (404m versus 153m; p &lt; 0,001) CONCLUSÃO: Ambos os testes promoveram alterações fisiológicas significativas. Apesar de o TE representar uma distância significativamente menor, a sobrecarga, bem como a percepção de trabalho, foi significativamente maior.

Self-Paced Walking within a Diverse Topographical Environment Elicits an Appropriate Training Stimulus for Cardiac Rehabilitation Patients

Purpose. To assess the effect of a self-paced walking intervention within a topographically varied outdoor environment on physiological and perceptual markers in cardiac rehabilitation (CR) patients. Methods. Sixteen phase II CR patients completed twelve self-paced one-mile walking sessions over a four-week period within a community-based CR programme. Walking velocity, heart rate (HR), and ratings of perceived exertion (RPE) were reported at eight stages throughout the self-paced walks. Results. The study showed a significant increase in walking velocity from week 1 (~4.5 km/h) to week 4 (~5.1 km/h) of the self-paced walking programme (P < .05). A significantly higher HR was also observed in week 4 (111 ± 13 b·min−1; ~69% of maximal HR) compared to week 1 (106 ± 14 b·min−1; ~65% of maximal HR, P < .001). There were no changes in the average RPE across the course of the 4-week self-paced walking programme (P > .05). Conclusion. A self-paced walking programme may elicit an appropriate training stimulus for CR patients when exercising within a diverse topographical environment. Participants completed a one-mile walk within a shorter period of time and at a higher physiological intensity than that elicited at the onset of the programme, despite no observed changes in participants' subjective perception of exertion.

Effects of a short-term differently dosed aerobic exercise on maximum aerobic capacity in breast cancer survivors: A pilot study

Regular physical activity and exercise improves quality of life and possibly reduces risk of disease relapse and prolongs survival in breast cancer survivors. The aim of this study was to evaluate the impact of a 3-week moderate intensity aerobic training, on aerobic capacity (VO2max) in breast cancer survivors. A prospective, randomized clinical study included 18 female breast cancer survivors in stage I-IIIA, in which the primary treatment was accomplished at least 3 months before the study inclusion. In all the patients VO2max was estimated using the Astrand's protocol on a bicycle-ergometer (before and after 3 weeks of training), while subjective assessment of exertion during training were estimated by the Category-Ratio RPE Scale. Each workout lasted 21 minutes: 3 minutes for warm-up and cool-down each and 15 min of full training, 2 times a week. The workload in the group E1 was predefined at the level of 45% to 65% of individual VO2max, and in the group E2 it was based on subjective evaluation of exertion, at the level marked 4-6. Data on the subjective feeling of exertion were collected after each training course in both groups. We recorded a statistically significant improvement in VO2max in both groups (E1--11.86%; E2--17.72%), with no significant differences between the groups. The workload level, determined by the percent of VO2max, was different between the groups E1 and E2 (50.47 +/- 7.02% vs 55.58 +/- 9.58%), as well as subjective perception of exertion (in the groups E1 and E2, 11.6% and 41.6% of training, respectively, was graded in the mark 6). In our group of breast cancer survivors, a 3-week moderate intensity aerobic training significantly improved the level of VO2max.

Análise comparativa e reprodutibilidade do teste de caminhada com carga progressiva (modificado) em crianças normais e em portadoras de fibrose cística

To analyze the shuttle walk test, and its respective retest, comparing children with cystic fibrosis (CF) to normal children. The children were divided into two groups: the CF group, composed of children in whom the diagnosis had been confirmed through sweat testing; and the control group, composed of normal children with no history of pulmonary diseases and no alterations in respiratory function. The children were submitted to at least two consecutive tests, 30 min apart. We evaluated distance walked, cardiac overload, peripheral oxygen saturation (SpO2) and subjective perception of exertion (dyspnea at rest scale and Borg dyspnea scale). A total of 28 children were evaluated. Ages ranged from 7 to 15 years (11.57 +/= 2.50 and 11.28 +/= 1.85 years for the CF and control groups, respectively). The Borg scale scores were significantly higher in the controls (p = 0.007). No differences were found regarding cardiac overload and SpO2. In relation to the intergroup retest, the controls presented significant improvements on the second test, both in the distance walked and in dyspnea at rest (p = 0.014 and p = 0.036, respectively). The CF group presented a significant improvement only in the dyspnea at rest score (p = 0.168 and p = 0.042, respectively). The cardiac overload imposed by the test did not differ between the groups. The greater fatigue at the beginning of the second test suggests that the 30 min rest between the tests was insufficient.

Self‐guided brisk walking training with or without poles: a randomized‐controlled trial in middle‐aged women

Walking with poles (Nordic walking, NW) has become popular. We compared training responses of brisk walking (W) or NW on cardiorespiratory and neuromuscular fitness. We randomized 121 non-obese sedentary women (aged 50-60) to an NW or W group (NWG, WG), to train 40 min four times weekly for 13 weeks. Intensity was based on subjective perception of exertion. Cardiorespiratory performance was assessed in four levels corresponding to 50%, 65%, 80% and 100% of peak VO(2). Fifty-four NWG and 53 WG subjects completed the study. The mean intensity was about 50% of heart rate (HR) reserve. The baseline peak VO(2) was 25.8 (SD 3.9) mL/min/kg. Both groups improved peak VO(2) similarly (NWG 2.5 mL/min/kg, 95% confidence interval (CI) 1.9-3.3; WG 2.6, CI 1.9-3.3). In the submaximal stages while walking with or without poles, HR and lactate decreased after training in both groups, but the changes were not statistically significantly different between the groups. Of the neuromuscular tests after training, the only significant difference between the groups was in the leg strength in the one-leg squat, favoring WG. In conclusion, both training modes improved similarly health-enhancing physical fitness, and they were feasible and safe.

Relationship between perceived exertion and mean power frequency of the EMG signal from the upper trapezius muscle during isometric shoulder elevation

The aim of the study was to investigate the relationship between a fatigue-induced increase of perceived exertion in the neck with a decrease of mean power frequency (MPF) in the surface electromyography (sEMG) signal during repeated shoulder elevation endurance tasks. About Thirty-two healthy women (age range 20-62) performed two maximum 6-min shoulder elevation endurance tasks at 30% of their maximal voluntary contraction (MVC) level, separated by a rest of 6 min. During these exercises, perceived exertion was estimated using the Borg scale (range 0-10), whereas the MPF of the sEMG signal from the upper trapezius was simultaneously detected. Linear regression analysis was applied over time for each trial and subject for both MPF and Borg scale rating values. The MPF was normalized by the intercept of the linear regression analysis. The resulting slopes of normalized mean power frequency (nMPF) and Borg scale rating were correlated with each other by linear regression for both trials. In order to investigate the individual behavior of fatigue effects between trials, Delta (trial 2-trial 1) slopes of nMPF and Borg scale ratings were calculated for each subject. These slopes of nMPF and Borg scale ratings were correlated with each other as well by linear regression. The increase of Borg scale ratings, as well as the decrease of nMPF, were significantly higher in trial 2 than trial 1 (P<0.01). The results show a linear correlation between slopes of nMPF and Borg scale ratings for both trials 1 and 2 (r=0.76, P<0.01). Trial-to-trial slopes (Delta (trial 2-trial 1)) of nMPF and Borg scale rating, were also significantly correlated (r=0.68, P<0.05). Thus, the individually sensed increase of perceived exertion in the neck during trial 2 was accompanied by a simultaneously higher detected decrease of nMPF. These findings indicate a close relationship between subjective perception of exertion in the neck and objectively assessed muscle fatigue of the upper trapezius.