Perceived Exertion Research Articles

Comparative Effects of Buteyko Breathing Technique and Active Cycle of Breathing Technique on Dyspnea and Quality of Life in Patients with Chronic Obstructive Pulmonary Disease

Background: Chronic Obstructive Pulmonary Disease (COPD) significantly impacts the quality of life due to symptoms like dyspnea. Non-pharmacological interventions, particularly breathing techniques, have gained attention for their potential to improve patient outcomes. Objective: This study aimed to compare the effectiveness of the Buteyko Breathing Technique (BBT) and the Active Cycle of Breathing Technique (ACBT) in reducing dyspnea and enhancing the quality of life in COPD patients. Methods: In a randomized clinical trial conducted at Jinnah Hospital, Lahore, 40 COPD patients (mean age 59.70 ± 5.89 years; 70% male) were assigned to either BBT or ACBT groups. Both groups received standard treatments of bronchodilators and inhaled corticosteroids. The intervention involved three sessions per week for six weeks. Dyspnea was measured using the Modified Borg Scale (MBS), and quality of life was assessed through the St. George’s Respiratory Questionnaire (SGRQ). Normality of data was confirmed via the Shapiro-Wilk test, and parametric tests (paired and independent T-tests) were used for statistical analysis. Results: Pre-treatment MBS in the BBT group was 6.7 ± 1.56, reducing to 2.9 ± 1.21 post-treatment. The SGRQ scores also showed improvement from 71.5 ± 8.44 to 36.8 ± 6.6. In the ACBT group, the MBS score decreased from 7.3 ± 1.56 to 3.95 ± 1.36, and SGRQ scores from 71.6 ± 8.46 to 42.55 ± 6.61. The between-group comparison indicated a more significant improvement in the BBT group, with post-treatment p-values of 0.01 for MBS and 0.009 for SGRQ. Conclusion: Both BBT and ACBT effectively improved dyspnea and quality of life in COPD patients, with BBT showing a greater impact. These findings suggest that BBT could be a preferable non-pharmacological intervention in COPD management. However, individual patient factors should be considered when choosing the appropriate technique.

Validity of using perceived exertion to assess muscle fatigue during bench press exercise

BACKGROUND: Muscle fatigue is nearly unavoidable during resistance exercise, yet evaluating it in such circumstances can be challenging. OBJECTIVE: This study aimed to evaluate the validity of using the rating of perceived exertion (RPE) as a measure of muscle fatigue during non-explosive bench press (BP) exercise. METHODS: Fifteen male collegiate athletes participated in three BP tasks set at 65% of their one-repetition maximum. The RPE, spectral fatigue index (SFI), and velocity loss were measured across different experimental conditions. RESULTS: Significant effects were observed across different experimental conditions for the overall RPE, average velocity loss, and average SFI (all p< 0.001). As the lifting tasks progressed, there were significant increases in the RPE, velocity loss, and SFI (p< 0.001). Additionally, significant differences were observed between the experimental conditions in the RPE (p< 0.001), SFI (p< 0.001), and velocity loss (p< 0.01). A significantly stronger (p< 0.05) correlation was observed between the RPE and SFI (r= 0.68, df= 117, p< 0.001) than between the velocity loss and SFI (r= 0.51, df= 117, p< 0.001). CONCLUSIONS: The corresponding changes observed in the RPE, velocity loss, and SFI suggest that both the RPE and velocity loss can be used as indicators of muscle fatigue during non-explosive BP exercise. However, due to the strong correlation between the RPE and SFI, RPE is more effective for reflecting muscle fatigue in non-explosive resistance exercise settings. Regarding ease of use, the RPE is more suitable than velocity loss for assessing muscle fatigue in training scenarios.

Application of Vagal-Mediated Heart Rate Variability and Subjective Markers to Optimise Training Prescription: An Olympic Athlete Case Report

Abstract Purpose: The aim of this case study was to investigate whether the variation in parasympathetic branch activity, in conjunction with subjective data, could optimize the training prescription for an elite athlete during an Olympic season. Methods: During the preparatory phase for the Tokyo Olympic Games, a world-class female 3000m steeplechase runner (Age: 20 years, Height: 168 cm, Weight: 52 kg, VO2max: 67.1 mL⋅min⋅kg-1) recorded Heart Rate Variability (HRV), conducted orthostatic tests, and completed subjective evaluations four times a week throughout the different training periods that constitute a pre-Olympic season. The Pearson correlation coefficient and the Shapiro-Wilk test, along with paired T-tests, were used to assess correlations and compare mean differences between variables concerning baseline measurements and each of the other training periods. Results: The natural logarithm of the root mean square of the standard deviation during supine measurement (LnRMSSDsu) exhibited a significant negative correlation with the training load based on Rating of Perceived Exertion (RPE) and sleep quality (P < 0.05). Heart rate during supine measurement (HRsu) showed a significant positive correlation with subjective perceived exertion, sleep quality, stress, muscle soreness, and fatigue (P < 0.01). Compared to the baseline (rest), LnRMSSDsu, HRsu, RPE, and sleep quality were significantly different during the training, camp, and altitude training camp periods. Conversely, markers of standing Heart Rate Variability (HRV) did not differ during competition periods. Conclusion: Standing Heart Rate Variability, when combined with subjective markers, serves as a relevant monitoring tool for adapting training periods to regulate psychophysiological effects.

Differences between 48 and 72-hour intervals on match load and subsequent recovery: a report from the Brazilian under-20 national football team

PurposeTo compare the external and internal load and subsequent recovery of football players after international tournament matches separated by 48 h vs. 72 h.MethodsA total of 14 male football players from the Brazilian National Team, competing in the 2019 South American Under-20 Championship, participated in the study. Match load was quantified using GPS variables and perceived exertion ratings (1). Additionally, before and 13–15 h after each match, players answered questions about the number of hours and quality of sleep, recovery status, and muscle soreness (0–10) and provided a blood sample for creatine kinase and reactive C-protein analysis. Values of all variables were compared between matches played with 48-h intervals (matches 1–4) and 72-h intervals (matches 5–8).ResultsNo significant differences in performance or perceptual parameters were observed between matches (p = 0.136–0.953). However, CK was higher in matches 1–4 compared to matches 5 and 6; and ΔPCR was higher in matches 2 and 3 compared to matches 5 and 6, and in match 4 compared to matches 5 and 8.ConclusionsAfter matches with a 48-h rest interval, players showed increased markers of inflammation and muscle damage compared to matches with a 72-h rest interval.

A single dose multi-ingredient pre-workout supplement enhances upper body resistance exercise performance.

Multi-ingredient pre-workout supplements (MIPS) are commonly used by individuals looking to enhance exercise performance and augment adaptations to training. However, the efficacy of commercially available MIPS is largely dependent on the ingredient profile, and new formulations should be investigated to determine their effectiveness. Therefore, the purpose of this study was to examine the effects of a commercially available MIPS product on performance during an upper body resistance exercise protocol. Twenty resistance-trained participants (10 men, 10 women) volunteered to complete this double-blind, placebo-controlled, crossover study consisting of 3 visits. Visit 1 consisted of body composition, 1-repetition maximum (1RM) testing, and familiarization. Visits 2 and 3 consisted of supplementation with either MIPS or placebo (PLA) 1 h prior to completion of an upper body resistance exercise workout during which power output, repetitions completed, rating of perceived exertion (RPE), and perceived recovery were recorded. Assessments of reaction time, isometric mid-thigh pull, and perceived levels of focus, energy, fatigue, and "muscle pump" were also completed before supplementation, 1 h after supplementation, and immediately after exercise. Statistical analysis revealed significant main effects of trial for reaction time (p < 0.001) and bench press peak power (p = 0.026) indicating better performance during the MIPS trial. Furthermore, total number of repetitions completed significantly increased (p = 0.003) during the MIPS (96.90 ± 21.31 repetitions) trial compared to PLA (89.50 ± 18.37 repetitions). Additionally, overall session RPE was significantly lower (p = 0.002) during the MIPS (7.6 ± 1.2) trial compared to PLA (8.3 ± 0.9). These findings suggest that acute supplementation with this MIPS improved upper body resistance exercise performance while reducing participant RPE. Further research should investigate the efficacy of chronic supplementation with this MIPS as the acute response provided an ergogenic benefit.

Do changes in mood and anxiety mediate exercise-induced reductions in alcohol cravings? An exploratory study.

Exercise is increasingly used as adjunct treatment for alcohol use disorder (AUD). Evidence suggests that moderate-to-high-intensity exercise can ameliorate cravings. We explored the potential mediating effects of changes in mood states in the relationship between exercise intensity and alcohol cravings. Secondary analyses of a nested single-arm trial within a randomized controlled trial (FitForChange). In total, 117 sedentary adults (68.4% female, M = 52 ± 12 years) with clinician diagnosed (Diagnostic and Statistical Manual of Mental Disorders, fifth edition) AUD and indications of craving (Desire for Alcohol Questionnaire) completed a 12-min submaximal cardiorespiratory fitness test on a cycle ergometer. Assessments of craving, mood states (POMS), and state anxiety (STAI-Y1) were taken immediately before, after, and 30 min after exercise. Ratings of perceived exertion (RPE) were included as indirect measures of exercise intensity. The med4way command in Stata was used to explore mediating and interaction effects of improvements in total mood disturbance (TMD) and state anxiety. Improvements in mood and anxiety did not mediate the effect of higher exercise intensity on reductions in alcohol craving. A significant reference interaction was found between "hard" (or greater) exertion and anxiety improvements (β = -1.06, 95% CI [-1.50, -0.61]). Participants whose anxiety reduced during exercise had two times higher odds of reduced cravings when exercising at a higher intensity than participants whose anxiety worsened (OR = 2.04, 95% CI [1.12, 3.72]). Reductions in anxiety may partly explain the positive effect of higher exercise intensity on alcohol cravings. The findings are preliminary and require replication in future studies. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The Effect of an Active Break Intervention on Nonspecific Low Back Pain and Musculoskeletal Discomfort during Prolonged Sitting among Young People-Protocol for a Randomized Controlled Trial.

The most recent evidence has shown that the pandemic of COVID-19 caused an increasing problem with spinal pain in the population of teenagers and young adults. This may be explained by prolonged sitting times in flexed positions with electronic devices. Positions maintained for a prolonged time cause overloading of soft tissue and discogenic symptoms. This study aims to evaluate the effectiveness of the active break program in reducing musculoskeletal discomfort and LBP (low back pain) among young people. This will be a randomized controlled study. The participants will be recruited from Bachelor's course students of the Physical Education Department aged 18-25 years. The participants will be assigned to an experimental group (with an active break) and a control group. The group with an active break with lumbar and hip extension exercises will be recommended to take a break for every 30 min of sitting. The control group will receive self-care recommendations. The primary outcomes will be pain intensity (Visual Analogue Scale), disability index (Oswestry Disability Index), and perceived musculoskeletal discomfort during prolonged sitting (Borg scale), assessed at baseline and after the intervention, and the Global Perceived Effect, only assessed after the 12-week intervention. The secondary outcome will be a Post-Intervention Questionnaire (a 5-item self-completed questionnaire), only assessed after the 12-week intervention. Our main research outcome-exercise protocols and interventions-will lead to the development of recommendations and protocols for the LBP population. It is important to determine the effect of interventions that are feasible and effective in addressing LBP and perceived musculoskeletal discomfort in young people. This is the first study examining the effect of active breaks with proposed lumbar and hip extension exercises on reducing or decreasing LBP in students based on a search of the literature. Exercises and recommendations will be the basis for developing proprietary preventative and therapeutic programs, which will be implemented in selected educational institutions.

Effectiveness of Aerobic Training with Strengthening Exercise on Endurance in Patients with Below Knee Amputation: Experimental study

Background: Below-knee amputation (BKA) is a condition in which the limb is amputated in the transtibial levelin which the distal tibia, fibula, whole of the ankle joint, and associated musculature and other components areremoved.Purpose: To determine the effect of aerobic training with strengthening exercise to increase endurance in patientswith below knee amputation.Materials and Methods: Total of 30 subjects with below knee amputation were selected based on the selectioncriteria. All the subjects were well elucidated about the objective of the study and the intervention and informedconsent was obtained before participating in this study. The subjects received strengthening exercise and aerobictraining for 4 weeks. The pretest values are taken with 6MWT and Borg scale; the same were recorded for post-testafter 4 weeks of intervention. The entire process was performed from November 2022 to March 2023.Result: Using a paired t-test to compare the pre and post-test results, the experiment revealed a significant differencein 6MWT and Borg scale. Independent sample t-test outcome at four weeks showed significant improvement inendurance.Conclusion: The results and the data obtained from this research was statically classified and can be concluded thatthere was a definite and positive effect of aerobic training with strengthening exercise and increased endurance inpatients with below knee amputation.

The effect of acupuncture on exercise capacity in patients with COPD is mediated by improvements of dyspnea and leg fatigue: a causal mediation analysis using data from a randomized controlled trial

BackgroundAcupuncture is known to improve exercise capacity in patients with chronic obstructive pulmonary disease (COPD), but its mechanism remains unknown. Whether acupuncture improves exercise capacity in patients with COPD through alleviation of leg fatigue and dyspnea is examined by applying causal mediation analysis to previous trial data.MethodsSixty-two patients with COPD completed treatments with either real or placebo acupuncture once a week for 12 weeks. Walk distance measured using the 6-minute walk test and intensities of leg fatigue and dyspnea in the modified Borg scale were evaluated at baseline and after treatment. The intervention effect of acupuncture against the placebo acupuncture on two mediators, changes in leg fatigue and dyspnea, and whether they mediated improvements in walk distance, were analyzed.ResultsLinear regression analysis showed that the unstandardized regression coefficients [95% confidence interval (CI)] for the intervention effect by acupuncture were -4.9 (-5.8–-4.0) in leg fatigue and -3.6 (-4.3–-2.9) in dyspnea. Mediation analysis showed that when changes in leg fatigue were considered as a mediator, direct effect, indirect effect and proportion mediated were 47.1 m (95% CI, 4.6–85.1), 34.3 m (-2.1–82.1), and 42.1%, respectively, and when changes in dyspnea were considered as a mediator, they were 9.8 m (-32.9–49.9), 72.5 m (31.3–121.0), and 88.1%, respectively, and the effects of joint mediator were -5.8 m (-55.4–43.9), 88.9 m (32.7–148.5), and 107.0%, respectively.ConclusionThe improvement in exercise capacity by acupuncture is explained by changes in both leg fatigue and dyspnea.

Energetics of sinusoidal exercise below and across critical power and the effects of fatigue

PurposePrevious studies investigating sinusoidal exercise were not devoted to an analysis of its energetics and of the effects of fatigue. We aimed to determine the contribution of aerobic and anaerobic lactic metabolism to the energy balance and investigate the fatigue effects on the cardiorespiratory and metabolic responses to sinusoidal protocols, across and below critical power (CP).MethodsEight males (26.6 ± 6.2 years; 75.6 ± 8.7 kg; maximum oxygen uptake 52.8 ± 7.9 ml·min−1·kg−1; CP 218 ± 13 W) underwent exhausting sinusoidal cycloergometric exercises, with sinusoid midpoint (MP) at CP (CPex) and 50 W below CP (CP-50ex). Sinusoid amplitude (AMP) and period were 50 W and 4 min, respectively. MP, AMP, and time-delay (tD) between mechanical and metabolic signals of expiratory ventilation (V˙E\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{V}}_{E}$$\\end{document}), oxygen uptake (V˙O2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{V}}_{{{\ ext{O}}}_{2}}$$\\end{document}), and heart rate (fH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${f}_{H}$$\\end{document}) were assessed sinusoid-by-sinusoid. Blood lactate ([La−]) and rate of perceived exertion (RPE) were determined at each sinusoid.ResultsV˙O2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{V}}_{{{\ ext{O}}}_{2}}$$\\end{document} AMP was 304 ± 11 and 488 ± 36 ml·min−1 in CPex and CP-50ex, respectively. Asymmetries between rising and declining sinusoid phases occurred in CPex (36.1 ± 7.7 vs. 41.4 ± 9.7 s for V˙O2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{V}}_{{{\ ext{O}}}_{2}}$$\\end{document}tD up and tD down, respectively; P < 0.01), with unchanged tDs. V˙O2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{V}}_{{{\ ext{O}}}_{2}}$$\\end{document} MP and RPE increased progressively during CPex. [La−] increased by 2.1 mM in CPex but remained stable during CP-50ex. Anaerobic contribution was larger in CPex than CP-50ex.ConclusionThe lower aerobic component during CPex than CP-50ex associated with lactate accumulation explained lower V˙O2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{V}}_{{{\ ext{O}}}_{2}}$$\\end{document} AMP in CPex. The asymmetries in CPex suggest progressive decline of muscle phosphocreatine concentration, leading to fatigue, as witnessed by RPE.

Validity and reliability of a repeated multi-changes of direction agility test in senior soccer players.

This study aimed to evaluate the validity, reliability, and sensitivity of repeated multi-changes of direction agility test (rMCOD) compared to a soccer-specific field test of repeated sprint ability (S-RSA) and repeated sprint ability test (RSA). Thirty-five healthy male soccer players (age: 18.4 ± 1.3 years) from Tunisan national soccer league (elite and sub-elite) took part in this study. They performed the tests in a randomized order over five sessions interspaced by at least 72 h. The construct, predictive and discriminant validity, relative and absolute reliability, and sensitivity of the tests were analyzed. The total and best time of the test (the sum for all trials and the trial with the lowest duration on nine, six, and seven attempts for rMCOD, RSA, and S-RSA, respectively), fatigue index, rating of perceived exertion (RPE), and lactate concentration were recorded. rMCOD correlated with both, S-RSA and RSA in total time (r = 0.85 and r = 0.52, respectively) and fatigue index (r = 0.74 and r = 0.83, respectively). Receiver operator characteristics were not able to discriminate between group levels (elite and sub-elite). When comparing training levels, only the fatigue index in S-RSA showed a difference between groups. Fatigue index, total time, and the best time in rMCOD showed excellent reliability, as well as the minimal change detectable (MCD = 0.89, MCD = 0.63, and MCD = 0.11, respectively) was higher than the standard error of the mean (SEM = 0.32, SEM = 0.23, and 0.04, respectively). rMCOD showed large to very large predictive validity compared with the S-RSA and RSA, being a reliable test for the following parameters: the best time and total time to perform the test. Nevertheless, this study design cannot ensure whether or not this test is able to detect real changes in performance in response to training since it did not include a training intervention; besides, rMCOD could not distinguish between elite and sub-elite players, which is a limitation.

Combined Accentuated Eccentric Loading and Rest Redistribution in High-Volume Back Squat: Acute Stimulus and Fatigue.

Chae, S, Long, SA, Lis, RP, McDowell, KW, Wagle, JP, Carroll, KM, Mizuguchi, S, and Stone, MH. Combined accentuated eccentric loading and rest redistribution in high-volume back squat: Acute stimulus and fatigue. J Strength Cond Res 38(4): 648-655, 2024-The purpose of this study was to examine acute stimulus and fatigue responses to combined accentuated eccentric loading and rest redistribution (AEL + RR). Resistance-trained men ( n = 12, 25.6 ± 4.4 years, 1.77 ± 0.06 m, and 81.7 ± 11.4 kg) completed a back squat (BS) 1 repetition maximum (1RM) and weight releaser familiarization session. Three BS exercise conditions (sets × repetitions × eccentric-concentric loading) consisted of (a) 3 × (5 × 2) × 110/60% (AEL + RR 5), (b) 3 × (2 × 5) × 110/60% (AEL + RR 2), and (c) 3 × 10 × 60/60% 1RM (traditional sets [TS]). Weight releasers (50% 1RM) were attached to every first repetition of each cluster set (every first, third, fifth, seventh, and ninth repetition in AEL + RR 5 and every first and sixth repetition in AEL + RR 2). The AEL + RR 5 resulted in greater total volume load (sets × repetitions × eccentric + concentric loading) (6,630 ± 1,210 kg) when compared with AEL + RR 2 (5,944 ± 1,085 kg) and TS (5,487 ± 1,002 kg). In addition, AEL + RR 5 led to significantly ( p < 0.05) greater rating of perceived exertion (RPE) after set 2 and set 3 and lower blood lactate (BL) after set 3 and 5, 15, and 25 minutes postexercise than AEL + RR 2 and TS. There was a main effect of condition for BL between AEL + RR 5 (5.11 ± 2.90 mmol·L -1 ), AEL + RR 2 (6.23 ± 3.22 mmol·L -1 ), and TS (6.15 ± 3.17 mmol·L -1 ). In summary, AEL + RR 5 results in unique stimulus and fatigue responses. Although it may increase perceived exertion, coaches could use AEL + RR 5 to achieve greater back squat total volume load while reducing BL accumulation.

Monitoring the recovery-stress states of athletes: Psychometric properties of the acute recovery and stress scale and short recovery stress scale among Dutch and Flemish athletes

ABSTRACT The Acute Recovery and Stress Scale (ARSS) and the Short Recovery and Stress Scale (SRSS) are recently-introduced instruments to monitor recovery and stress processes in athletes. In this study, our aims were to replicate and extend previous psychometric assessments of the instruments, by incorporating recovery and stress dimensions into one model. Therefore, we conducted five confirmatory factor analyses (CFA) and determined structural validity, internal consistency, and construct validity. Dutch and Flemish athletes (N = 385, 213 females, 170 males, 2 others, 21.03 ± 5.44 years) completed the translated ARSS and SRSS, the Recovery Stress Questionnaire for Athletes (RESTQ-Sport-76), the Rating of Perceived Exertion (RPE) and the Total Quality of Recovery (TQR). There was a good model fit for the replicated CFA, sub-optimal model fit for the models that incorporated recovery and stress into one model, and satisfactory internal consistency (α=.75 – .87). The correlations within and between the ARSS and SRSS, as well as between the ARSS/SRSS and the RESTQ-Sport-76 (r = .31 – -.77 for the ARSS, r = .28 – -.63 for the SRSS), the RPE (r = .19 – -.23), and the TQR (r = .63 – -.63) also supported construct validity. The combined findings support the use of the ARSS and SRSS to assess stress and recovery in sports-related research and practice.

Higher rating of perceived exertion and lower perceived recovery following a graded exercise test during menses compared to non-bleeding days in untrained females.

The underrepresentation of the female population in exercise sciences could be attributed, at least in part, to difficulty in appropriately accounting for the effects of the menstrual cycle (MC). Previous studies examining the effects of the MC on aerobic performance and subjective measures of aerobic performance show conflicting results. Purpose: The study examined how the MC affects the objective and subjective measures of aerobic performance within untrained female participants and in comparison with untrained male participants assessed at similar time intervals. Methods: Twenty-one participants (12 females and 9 males) completed a graded exercise test (GXT) on a cycle ergometer. The female participants were tested during their early follicular (EF; menses), ovulatory (O), and mid-luteal (ML) phases of the MC. The male participants were included as the control group and were randomly assigned to a menstrual cycle phase for each visit. During GXT, maximal oxygen consumption (VO2max), respiratory exchange ratio (RER), maximal heart rate (HRmax), peak blood lactate, and rating of perceived exertion (RPE) were determined. Twenty-four hours post-exercise, the perceived recovery status (PRS) was assessed. The MC phase was estimated using basal body temperature (BBT) in the female participants. Results: The male participants obtained a higher peak power and VO2max compared to the female participants (p < 0.05). All objective measures of aerobic performance did not significantly differ across the MC phases or time points that were tested. In the untrained female participants, an effect of the MC phase on RPE was found, with RPE being higher at EF (8.92 ± 0.79) compared to O (7.67 ± 1.23; p < 0.05) and ML (7.75 ± 1.06; p < 0.05). In addition, an effect of the MC phase on PRS was found, with perceived recovery being lower at EF (6.83 ± 0.94) compared to O (8.83 ± 1.12) and ML (8.67 ± 0.65; all p < 0.005) for the untrained female participants. No significant differences in RPE and PRS were found between tests in the untrained male participants. The female participants had lower perceived recovery following EF (6.83 ± 0.94) compared with the male participants (9.00 ± 1.00; p < 0.001). Conclusion: The untrained female participants perceived greater exertion during GXT and impaired recovery following GXT in EF compared to O and ML. These results may be attributed to either a drop in female sex hormone concentrations or discomfort associated with menses. The male participants did not exhibit any changes over time. Future studies using subjective parameters such as perceived exertion to track the internal load of training in the naturally menstruating female population should consider menses.

To Analyze Pilates’ Impact on the Childbirth Process and its Results in Pregnant Females : Observational Study

Background: Pilates Method as been a popular background for almost a century and is now used worldwide as a form of fitness and holistic health because it can be tailored to individual needs and fitness levels. Lucia first advised mat exercises performed on the floor, adapting them to individual physical and temporal constraints without compromising the wider element. He later labeled a series of specialized devices, including springs and rollers, that provide resistance to develop divergent movement patterns.13Performing exercise with medium intensity has positive effects on the maternal health. The goal of obstetriccare is to provide the right conditions for a safe delivery and make it a pleasant experience. Labor pain is anunavoidable component ofchild birth whose proper management, despite the great advances in midwifery, is still one of the major challenges related to women’s health. Pregnant women should also be clinically evaluated before starting exercise to ensure there is no medical reason to stop exercising.Methods:Patients were randomly divided into two groups of 15 people in each group. In the intervention group,a Pilates exercise program was developed in collaboration with a Pilates trainer. The program was tailored to the susceptibility of pregnant women and was administered twice weekly for 8 weeks.Four tools were used in this study, including a two-part checklist, the Borg Rating of Perceived Exertion (RPE),the Visual Analogue Scale (VAS), and the McKee Childbirth Satisfaction Rating Scale. A two-section checklist was used in this study to collect the required information.Conclusion:, According to the results of this study, Pilates exercise during pregnancy is a safe method to reduce the length of the active phase and second stage of labor, reducelabor pain, and increase maternal satisfaction with the child birth process. However, Pilates exercise did not significantlyreduce the need to episiotomy and caesarean section.

The six minute walk test in healthy young women

ObjectivesThe Six Minute Walk Test (6MWT) assesses functional capacity. We determined the reference range distance walked, heart rate change, and breathlessness in healthy women. DesignProspective observational study. Methods100 nulliparous women aged 18–40 performed two 6MWTs, with the second performed after heart rate returned to baseline. Borg scales compared expected and true breathlessness. ResultsReference range was 472–758 ​m, with distance mean (SD) of 615 (73.0) metres. Heart rate increase during exercise was 11 (11.8) beats per minute, recovering to baseline in 4.5 (3.9) minutes. 63 ​% of women overestimated breathlessness. ConclusionsThese data represent reference values for functional evaluation of healthy young women.

Isolated but not combined ergogenic effects of caffeine and L-arginine during an isokinetic knee extension.

The use of single supplements as ergogenic aids to enhance performance in strength-oriented sports is widespread among athletes (74%). The aim of this study was to increase knowledge about the combined effects of caffeine and L-arginine dietary supplements on performance. In this double-blind, randomized and counterbalanced crossover study, 29 participants (age: 23.2 ± 3.6 yr.; height: 181.0 ± 7.6 cm; weight: 77.0 ± 8.8 kg) each underwent six trials. In each trial performance tests were conducted to examine the effects of the supplement combinations on maximum (NmMax) and averaged torque (NmM), maximum (JMax) and averaged work (JM), the blockwise mean values of torque and work, and rate of perceived exertion (RPE) during an isokinetic leg extension task (90°·s-1) with the right leg for two sets of 40 repetitions and a set rest of 3 min on a dynamometer. The first and second trials were used to familiarize the participants with the movements in the dynamometer and no supplements were taken. After this 2-week pre-test trial, the supplement combinations of placebo/placebo, caffeine/placebo (5 mg·kg-1), L-arginine/placebo (0.15 g·kg-1), and caffeine/L-arginine (5 mg·kg-1 + 0.15 g·kg-1) were ingested. The main finding of this study is the absence of an ergogenic effect of the combined supplements caffeine and L-arginine during voluntary maximal isokinetic leg extensions, although an increase of 3.5% was noted for Nmmax compared to the placebo trial. However, the administration of caffeine was able to increase the NmMax of the quadriceps femoris muscle about 5.1% (p = 0.043). In addition, caffeine (4.2%, p = 0.026) and also L-arginine (4.2%, p = 0.040) significantly increased NmM over a complete set. No single or combined supplement had an effect on muscle fatigue looking at the blockwise mean values of torque and work or RPE (all p > 0.05). The combination of caffeine and L-arginine was not superior to the isolated intake of both supplements in a strength-based exercise and a synergistic effect was absent.

A One Session Gait Retraining Protocol with Metronome Augmentation Increases Cadence in Novice and Recreational Runners.

Running is a common leisure physical activity that carries a risk for running related injury (RRI). Non-experienced runners are more likely to sustain RRIs. One form of gait retraining focuses on increasing cadence to improve running biomechanics related to RRI. Protocols for increasing cadence must be pragmatic to be implemented into clinical practice. The purpose of this study was to determine if a pragmatic protocol including one instructional session, followed by independent gait retraining with metronome augmentation resulted in increased cadence and altered biomechanics in novice and recreational runners. Randomized Controlled Trial. Thirty-three novice or recreational adult runners completed a 12 Minute Cooper Run on an indoor track. Variables measured during the 12 Minute Cooper Run included distance, rate of perceived exertion (RPE), heart rate (HR), and 3-D biomechanics using inertial measurement units (IMUs). After baseline testing, the intervention group received instruction and five minutes of gait retraining at a cadence set 5-10% higher than baseline with metronome augmentation (Pro Metronome- Tempo, Beat; by Xiao Yixiang). They then ran two to three times a week for two weeks up to 30 minutes per session with the metronome set at the new cadence. After two weeks, repeat testing using the same protocol was completed. A Mann-Whitney U test analyzed differences between groups. Cadence at one minute (p = 0.037) and average cadence over the entire run (p=0.002) increased in the intervention group only with a large effect size (Cohens d = 0.837). No other group differences were found. A pragmatic gait retraining protocol with metronome augmentation including one instructional and four to six independent sessions over a two-week duration increased cadence without negative effects on HR, RPE, distance. Biomechanics did not change with this intervention. Further research with pragmatic gait retraining protocols that increase cadence are needed with larger sample sizes, repeated measures over time, across runners of various abilities and experience levels. Level 2.

Yohimbine Ingestion Mitigates Morning-Associated Decrements in High-Intensity Exercise Performance

Exercise performance tends to suffer during the morning compared to the evening, which may decrease potential training adaptations. Currently, it is unclear how nutritional interventions may affect this phenomenon and whether supplementation may allow for the attainment of optimal performance regardless of the time of day. The purpose of this study was to investigate the effects of acute yohimbine ingestion on morning-associated decrements in performance and psychophysiological responses to exercise. Physically active females (n = 16) were recruited to participate in three total visits, each with a different treatment: (1) placebo-morning (PL-AM), (2) yohimbine-morning (YHM-AM; oral 2.5 mg), and (3) placebo-afternoon (PM). The morning and afternoon visits occurred between 7:00–8:00 h and 16:00–17:00 h, respectively. The experimental treatments in the morning were ingested 20 min prior to capillary blood collection, which was completed pre- and post-exercise. Following a warm-up, participants completed a 2000 m time trial on a rowing ergometer. Power output, heart rate (HR), and rating of perceived exertion (RPE) were recorded every minute. Time to competition (TTC) and subjective energy, focus, and alertness were documented post-exercise. Pre- and post-exercise blood lactate (La) and plasma hypoxanthine (HX) levels were also assessed. The trials were separated by a 48 h washout period. The results showed that power output (p = 0.010) was lower and TTC (p = 0.003) was significantly slower with PL-AM compared to PM. Furthermore, YHM-AM resulted in higher power output (p = 0.035) and faster TTC (p = 0.007) compared to PL-AM, with no differences compared to PM (p &gt; 0.05). Post-exercise La was significantly lower with YHM-AM compared to PL-AM (p = 0.046) and PM (p = 0.001). Pre-exercise plasma HX, as measured via conversion to xanthine, was significantly higher with PM (p = 0.039), while the levels trended higher with YHM-AM (p = 0.060) compared to PL-AM. Subjective energy was higher with YHM-AM (p = 0.045) and PM (p = 0.009) compared to PL-AM, while alertness was only higher for YHM-AM compared to PL-AM (p = 0.045). No statistical differences between the treatments were found for RPE or HR (p &gt; 0.05). These findings indicate that YHM ingestion attenuates performance decrements in the morning. Improvements in performance may be underpinned by improved feelings of energy and alterations in metabolism. Practically, YHM may represent an effective ergogenic aid to combat a lack of energy and low performance during the morning.

The effects of sustained, low- and high-intensity isometric tasks on performance fatigability and the perceived responses that contributed to task termination.

The present study examined the effects of sustained, isometric low- versus high-intensity tasks on time to task failure (TTF), performance fatigability (PF), ratings of perceived exertion (RPE), and the perceived causes of task termination from a post-test questionnaire (PTQ). Ten men (mean ± SD: age = 21.1 ± 2.3 years; height = 180.2 ± 5.7 cm; body mass = 79.5 ± 8.8 kg) performed maximal voluntary isometric contractions (MVICs) before and after fatiguing, isometric forearm flexion tasks anchored to the torque corresponding to RPE values of 2 (TRQ2FT = 23.8 ± 7.1 N·m) and 8 (TRQ8FT = 60.9 ± 11.4 N·m). In addition, the subjects completed a PTQ which surveyed whether the perceived sensations of fatigue or pain, and/or the psychological factors of loss of focus and motivation contributed to the decision to terminate the task. Repeated measures ANOVAs, Wilcoxon-Signed Rank tests, and Spearman's Rank-Order Correlations were used to analyze the data. Across the fatiguing tasks, there were similar decreases in MVIC torque (95.2 ± 20.3 vs. 68.9 ± 15.6 N·m; p < 0.001) and RPE values (p = 0.122) at task failure for TRQ2FT (7.4 ± 2.7) and TRQ8FT (8.9 ± 1.0), but a longer (p = 0.005) TTF for the TRQ2FT (245.0 ± 177.0 s) than TRQ8FT (36.8 ± 11.1 s). Despite reaching task failure, the subjects were able to perform MVICs that were 100-300% greater than the target torque values within seconds of terminating the tasks. Thus, we hypothesized that task failure was not caused by an inability to produce sufficient torque to sustain the tasks, but rather an unwillingness to continue the task.