Effects of different resistance training programmings on the relative strength, body composition, anthropometric variables, and metabolic risk of elderly women.

The purpose of this study was to analyze the effect of two different programming models of resistance training (RT) on metabolic risk, anthropometric variables, and relative strength in elderly women. The research was a prospective and comparative longitudinal study with a non-probabilistic random sample. Twenty-two elderly women (64 ± 3 years) was divided into two experimental groups being the Linear programming (LP, n = 12) and Daily undulatory programming (DUP, n = 10), with 3 sessions/week for 12 weeks. Submaximal strength (10RM) was evaluated in the horizontal leg press (HL), pulldown (PD), leg curl (LC), vertical bench press (BP), and leg extension (LE). Anthropometric variables, food intake (R24h) and submaximal strength (10RM) was analyzed. Participants were initially classified as overweight or obese evaluated by body mass index (BMI) and percentual of fat mass (%FM) and with moderate to high risk to develop metabolic diseases evaluated by hip-waist ratio (HWR), waist-height ratio (WHR) and waist circumference (WC). There is no change for metabolic risk and anthropometric variables after the intervention period. There was a significant improvement for relative strength accessed by 10RM and body weight (10RM/BW), and lean body mass (10RM/LBM) (p < 0.05), with large or medium effect size for most of variables after 12 weeks of RT. As a conclusion, both programmings increased relative strength after 12 weeks of RT with attenuated change in body composition and metabolic risk in elderly women in both programming groups and all those strategies can be used in elderly women to improve strength.

Carbohydrate mouth rinse failed to reduce central fatigue, lower perceived exertion, and improve performance during incremental exercise.

We examined if carbohydrate (CHO) mouth rinse may reduce central fatigue and perceived exertion, thus improving maximal incremental test (MIT) performance. Nine recreational cyclists warmed up for 6 min before rinsing a carbohydrate (CHO) or placebo (PLA) solution in their mouth for 10 s in a double-blind, counterbalanced manner. Thereafter, they performed the MIT (25 W·min-1 increases until exhaustion) while cardiopulmonary and ratings of perceived exertion (RPE) responses were obtained. Pre- to post-MIT alterations in voluntary activation (VA) and peak twitch torque (Tw) were determined. Time-to-exhaustion (p = 0.24), peak power output (PPO; p = 0.45), and V̇O2MAX (p = 0.60) were comparable between conditions. Neither treatment main effect nor time-treatment interaction effect were observed in the first and second ventilatory threshold when expressed as absolute or relative V̇O2 (p = 0.78 and p = 0.96, respectively) and power output (p = 0.28 and p = 0.45, respectively) values, although with moderate-to-large effect sizes. RPE increased similarly throughout the tests and was comparable at the ventilatory thresholds (p = 0.56). Despite the time main effect revealing an MIT-induced central and peripheral fatigue as indicated by the reduced VA and Tw, CHO mouth rinse was ineffective in attenuating both fatigues. Hence, rinsing the mouth with CHO was ineffective in reducing central fatigue, lowering RPE, and improving MIT performance expressed as PPO and time-to-exhaustion. However, moderate-to-large effect sizes in power output values at VT1 and VT2 may suggest some beneficial CHO mouth rinse effects on these MIT outcomes.

Tampa Scale for Kinesiophobia in chronic neck pain patients (TSK-neck): structural and construct validity and reliability in a Brazilian population.

BACKGROUND: To date, there are no studies in the literature that define the internal structure of the Tampa Scale for Kinesiophobia (TSK) in patients with chronic neck pain based on factorial analysis. As such, we aimed to verify and identify the best structure of the Brazilian version of the TSK in patients with chronic neck pain. METHODS: We included Brazilian participants aged ≥18 years, both sexes, with self-reported neck pain for more than 3 months and pain intensity ≥3 on the Numerical Pain Rating Scale (NPRS). Dimensionality and number of TSK items were assessed using confirmatory factor analysis (CFA). We tested the following internal structures: structure 1 (1 domain and 17 items), structure 2 (1 domain and 11 items), structure 3 (2 domains and 11 items), and structure 4 (2 domains and 9 items). We used the Pain-Related Catastrophizing Thoughts Scale (PCTS) and the NPRS for construct validity. In addition, we assessed test-retest reliability for the seven-day interval using intraclass correlation coefficient (ICC2,1), Cronbach's alpha to assess internal consistency, and ceiling and floor effects. RESULTS: The study sample included of 335 patients. Most were women (77.6%), young adults (~ 34 years), single (48.4%), with complete primary education (57.3%), physically inactive (66.6%), with a mean pain duration of 46 months and a mean pain intensity of ~ 5 points on the NPRS. Redundancy was found in the following items: item 1 with item 2 (modification indices = 21.419) and item 13 with item 15 (modification indices = 13.641). Subsequently, based on these paired analyses, the items with the lowest factor loadings (items 2 and 15) were excluded. As such, TSK structure 4 was composed of two domains ("somatic focus" and "activity avoidance") and 9 items, which showed adequate fit indices and lower AIC and SABIC values. We observed significant values (p < 0.05) with a correlation magnitude greater than 0.142 to 0.657 between the two domains of the TSK-neck and the other instruments (PCTS and NPRS). We found excellent reliability (ICC2,1 ≥ 0.96) and adequate internal consistency (Cronbach's alpha ≥0.98) of the TSK-neck. Finally, ceiling and floor effects were not observed. CONCLUSION: The TSK-neck structure with two domains (somatic focus and activity avoidance) and nine items is the most appropriate for patients with chronic neck pain.

Anterior Knee Pain Scale (AKPS): structural and criterion validity in Brazilian population with patellofemoral pain.

PURPOSE: To identify the best internal structure of the Brazilian version of the Anterior Knee Pain Scale (AKPS), comparing different instrument structures (structural validity) and correlating the scores of the versions (criterion validity). METHODS: We included Brazilian volunteers, aged ≥ 18 years, with patellofemoral pain (PFP) for at least 3 months. We used the confirmatory factor analysis and considered the following fit indices: chi-square/degrees of freedom (DF), comparative fit index (CFI), Tucker-Lewis index (TLI), root mean square error of approximation (RMSEA). We considered the structure with the lowest values of the Akaike information criterion (AIC), sample size adjusted Bayesian information criterion (SABIC), and assessed criterion validity using Pearson correlation coefficient (r) to correlate the long and short versions. RESULTS: The study included 101 participants, mostly women (65.3%), young adults (~ 31 years old), overweight (BMI > 25 kg/m2), incomplete higher education (37.6%), and physically active (64.4%). The original 1-domain, 13-item structure showed adequate fit indices (chi-square/GL < 3.00, TLI and CFI > 0.90, and RMSEA < 0, 08). However, items 11 and 12 had a factorial load of less than 0.23. Therefore, we excluded items 11 and 12 and found adequate fit indices (chi-square/GL < 3.00, TLI and CFI > 0.90, and RMSEA < 0, 08) and lower AIC and SABIC values. We observed a correlation coefficient above the acceptable cutoff of 0.70 (r = 0.966, p-value < 0.001) between the versions. CONCLUSION: The 11-item AKPS (without items 11 and 12) is the version with the most adequate internal structure and correlates satisfactorily with the long version of the instrument.

Carbohydrate mouth rinse improves performance of mentally fatigued cyclists despite null effects on psychological responses.

Mental fatigue reduces exercise performance through an impaired psychological response such as increased perceived exertion. Carbohydrate (CHO) mouth rinses improve exercise performance and perceived exertion likely due to an improved activation in cerebral reward areas, then we investigated if the CHO mouth rinse-improved exercise performance in mentally fatigued individuals was associated with ameliorated reward-related psychological responses. We hypothesised that CHO mouth rinse would be beneficial for mentally fatigued cyclists mainly in high-metabolic disturbance intensities. After familiarization and baseline sessions, well trained cyclists (n = 20) performed a maximal incremental test (MIT) after mental fatigue induction. They completed the MIT either without mouth rinse (MF) or rinsing their mouth with CHO (MF+CHO) or placebo (FM+PLA) solutions at every 25 % of the MIT. Psychological responses such as ratings of perceived exertion (RPE), affective valence, emotional arousal, and motivation were assessed throughout the MIT, while performance was assessed as peak power output and time of exercise. Mental fatigue reduced MIT performance (P < 0.05), but CHO mouth rinse was effective to counteract this deleterious mental fatigue effect (P < 0.05). However, we found null effects of CHO mouth rinses in psychological responses above the VT2 (P > 0.05) such as RPE, affective valence, emotional arousal, and motivation. Correlational analysis showed a significant, but moderate negative correlation between motivation and time of exercise above the VT2 when participants used CHO mouth rinse. In conclusion, the ergogenic CHO mouth rinse effects on MIT performance of mentally fatigued cyclists were irrespective of ameliorated psychological responses to exercise.

No Evidence of Postactivation Performance Enhancement on Endurance Exercises: A Comprehensive Systematic Review and Meta-analysis.

PURPOSE: Narrative reviews have suggested that postactivation induced by warm-up routines is effective to increase endurance exercise performance in real-world scenarios. However, systematic reviews with meta-analysis rather than narrative ones are required to provide an up-to-date summary of the evidence and provide directions for practical decisions. Therefore, we systematically reviewed peer-reviewed and gray literature to determine the certainty of evidence and the relative effects of postactivation performance enhancement (PAPE) in endurance exercises. METHODS: The effects of PAPE on endurance performance were meta-analyzed as a standardized mean difference (SMD) from control conditions within a random-effects model considering polled data and subgroups (PAPE strategies, endurance test modalities, and V̇O 2max -based endurance level). RESULTS: Eligible studies ( n = 35) showed a high risk of bias due to methodological flaws in randomization and blinding procedures. A meta-analysis including 57 comparisons (432 participants) revealed a significant but very small PAPE effect on endurance performance ( Z = 2.49, SMD = 0.15-very small, 95% confidence interval = 0.03 to 0.28) due to exceptional effect sizes reported by two studies (SMD of 2.85 and 2.14). We also observed that neither PAPE strategies nor endurance test modalities or V̇O 2max -based endurance levels influenced the PAPE effects on endurance performance. Meta-regression showed that PAPE effects were correlated neither with the time interval between conditioning routines and endurance exercise nor with endurance exercise duration. We found a very low certainty of evidence that PAPE potentiates endurance performance. CONCLUSIONS: Based on the analyses of bias and certainty of evidence, we found no support to recommend PAPE strategies to improve endurance exercise performance. Significant but very small PAPE effects on endurance performance were due to two exceptional effect sizes.

Unilateral seated shot-put test, muscle strength, and range of motion on recreational athletes with chronic shoulder pain: Cross-sectional study.

OBJECTIVE: To correlate the functional performance assessed by means of the Unilateral Seated Shot-Put Test (SSPT) with shoulder muscle strength, range of motion (ROM), and handgrip strength in recreational athletes with chronic shoulder pain. METHODS AND MATERIALS: The sample was composed of recreational athletes with nonspecific pain in the dominant shoulder ≥3 months, both sexes, aged between 18 and 45 years. We diagnosed shoulder pain by reporting pain intensity ≥3 points on the Numerical Rating Pain Scale and used the Shoulder Pain and Disability Index, Pain-Related Catastrophizing Thoughts Scale, and Baecke Questionnaire. Moreover, shoulder muscle strength, handgrip strength, ROM, and functional performance using the SSPT were evaluated. We used the Spearman correlation coefficient to investigate the correlation between the variables. RESULTS: Nineteen participants were included. Most of the sample consisted of adult women with adequate body mass and pain predominantly in the right shoulder. We observed higher correlation magnitudes of the SSPT with handgrip strength (rho = 0.818 to 0.833, p < 0.05). Correlations of the SPPT with shoulder musculature strength were of low to moderate magnitude (rho = 0.461 to 0.672, p < 0.05). The only significant correlation (p < 0.05) found was between the SSPT and ROM (horizontal adduction), however, with a weak magnitude (rho <0.50). CONCLUSION: SSPT correlates strongly with handgrip strength and moderately with shoulder muscle strength in recreational athletes with chronic shoulder pain.

The placebo effect of a pink non-caloric, artificially sweetened solution on strength endurance performance and psychological responses in trained individuals.

Background: The pink color enhances the perceived sweetness, increasing the individuals' expectation of the presence of sugar/carbohydrate in a beverage. Hence, it is plausible to speculate that providing a pink solution during exercise could induce an ergogenic benefit through a potential placebo effect. Aim: We examined whether ingesting a pink non-caloric, artificially sweetened solution can improve endurance strength exercise performance and psychological responses. Methods: Eighteen strength-trained individuals (34 ± 7 y; 1.74 ± 0.06 m; 79.86 ± 10.91 kg) completed three experimental trials in a randomized, single-blind, crossover counterbalanced fashion. In each trial, participants performed a 5-set strength endurance test at 70% of the one-repetition maximum in the bench press exercise, interspersed by 2 min. Before each set, participants ingested either a pink (PINK) or a transparent (TRANSP) non-caloric, artificially sweetened solution. A session without ingestion (CON) was also completed. Total number of repetitions and psychological responses such as motivation, emotional arousal, affect, and ratings of perceived exertion were obtained throughout the exercise protocol. Results: Total repetitions improved in PINK (60 ± 12 reps) compared to TRANSP (p = 0.03; 56 ± 10 reps; ES = 0.22; ±3.8%) and CON (p = 0.01; 56 ± 9 reps; ES = 0.33; ±6.6%), but no difference occurred between TRANSP and CON (p = 0.84; ES = 0.12; ±2.4%). Comparable responses were observed in motivation, emotional arousal, affect, and ratings of perceived exertion in PINK, TRANSP, and CON trials (all, p > 0.05), despite the greater total physical work performed in PINK trial. Conclusion: Ingesting a pink non-caloric, artificially sweetened solution improved strength endurance performance with comparable psychological responses. These results have implications for future nutritional studies and performance assessments in real-world sports scenarios.

Reliability of the Heart Rate Variability Registered Through Polar Cardio Frequency Meter in Individuals With Chronic Low Back Pain.

Objective: The purpose of this study was to analyze the intra- and inter-examiner reliability of the analysis of heart rate variability (HRV) captured by a Polar cardio frequency meter in individuals with chronic nonspecific low back pain. Methods: The study included 35 individuals with nonspecific low back pain, both sexes, aged 18 to 45. We used a Polar V800 cardio frequency meter to capture HRV in individuals in different positions, and we calculated the reliability through the intraclass correlation coefficient (ICC). Results: Regarding intra-examiner reliability, we found excellent reliability of HRV analysis in the supine position (ICC ranging from 0.89 to 1.00) and in the standing position (ICC ranging from 0.95 to 0.99). In addition, for inter-examiner reliability, we found substantial to excellent reliability of the HRV analysis in the supine position (ICC ranging from 0.76 to 0.98) and moderate to excellent reliability in the standing position (ICC ranging from 0.73 to 0.99). Conclusion: The HRV analysis captured by a Polar cardio frequency meter presented adequate reliability when considering different times and different examiners.

15-item Roland-Morris disability questionnaire for general pain (RMDQ-g): Structural validity and criterion validity on Brazilian patients with chronic pain.

BACKGROUND: Roland-Morris Disability Questionnaire for general pain (RMDQ-g) is an instrument adapted to assess disability in patients with pain in any region of the body. OBJECTIVE: To perform the structural and criterion validity of the RMDQ-g in Brazilian patients with chronic pain. DESIGN: A cross-sectional study. METHODS: We included native speakers of Brazilian Portuguese, of both sexes, aged ≥18 years, with pain for at least 3 months in any region of the body. Participants eligible for the study responded to an online form containing personal and clinical data, and assessment instruments. We used the confirmatory factor analysis and considered the following fit indices: chi-square/degree of freedom (DF), comparative fit index (CFI), Tucker-Lewis index (TLI), root mean square error of approximation (RMSEA). In the comparison between models, we considered the structure with the lowest values of the Akaike information criterion (AIC) and sample-size adjusted Bayesian information criterion (SABIC). We assessed criterion validity via Spearman's correlation coefficient (rho) to correlate the long and short versions. RESULTS: The study consisted of 297 participants with chronic pain. The main sites of pain were the lumbar region (40.7%), thoracic (21.5%), and neck (19.5%). Mean pain intensity was greater than 5 points. The 24-item long version and the 15-item short version had adequate fit indices (chi-square/DF ≤ 1.77, CFI ≥0.97, TLI ≥0.96, and RMSEA ≤0.05). However, when comparing structures, the short version was the most appropriate because it had the lowest values of AIC (2562.05) and SABIC (2577.72). Criterion validity was acceptable (rho = 0.94) and internal consistency as well (Cronbach's alpha = 0.87). CONCLUSION: The structural validity and criterion validity of the RMDQ-g with one domain and 15 items is the most appropriate version and should be considered in the clinical environment and in research for measuring disability in patients with chronic pain in any region of the body.

Music Alters Conscious Distance Monitoring without Changing Pacing and Performance during a Cycling Time Trial.

Athletes use their own perception to monitor distance and regulate their pace during exercise, avoiding premature fatigue before the endpoint. On the other hand, they may also listen to music while training and exercising. Given the potential role of music as a distractor, we verified if music influenced the athletes' ability to monitor the distance covered during a 20-km cycling time trial (TT20km). We hypothesized that music would elongate cyclists' perceived distance due to reduced attentional focus on exercise-derived signals, which would also change their ratings of perceived exertion (RPE). We also expected that the motivational role of music would also be beneficial in pacing and performance. After familiarization sessions, ten recreational cyclists performed an in-laboratory TT20km while either listening to music or not (control). They reported their RPE, associative thoughts to exercise (ATE), and motivation when they each perceived they had completed 2-km. Power output and heart rate (HR) were continuously recorded. Cyclists elongated their distance perception with music, increasing the distance covered for each perceived 2 km (p = 0.003). However, music reduced the error of conscious distance monitoring (p = 0.021), pushing the perceived distance towards the actual distance. Music increased the actual distance-RPE relationship (p = 0.004) and reduced ATE (p < 0.001). However, music affected neither performance assessed as mean power output (p = 0.564) and time (p = 0.524) nor psychophysiological responses such as HR (p = 0.066), RPE (p = 0.069), and motivation (p = 0.515). Cyclists elongated their distance perception during the TT20km and changed the actual distance-RPE relationship, which is likely due to a music-distractive effect. Although there was a reduced error of conscious distance monitoring, music affected neither pacing nor performance.

Reliability of the Heartbeat Tracking Task to Assess Interoception.

Interoception refers to the competence in perceiving and interpreting internal sensations emerging from the body. The most common approach to assess interoception is through cardiac interoceptive tests like the heartbeat tracking task (HTT), which measures the accuracy on perceive and counting heartbeats during a period. However, the literature is scarce in providing adequate reliability evidence for this measure so that the interoception assessment may be threaten. In addition to HTT accuracy, it is possible to determine sensibility (self-reported confidence) and interoceptive awareness (correspondence between accuracy and sensibility). Thus, we measured the test-retest reliability of HTT and also investigated the behavior of HTT outcomes along the task. Therefore, 31 healthy adults (16 males) with 27.8 (9.4) years old performed two consecutive HTT interspersed by one day. Intraclass correlation coefficient (ICC), standard error of measurement (SEM) and minimal detectable difference (MD) analyzes showed 'Good' relative reliability for interoceptive accuracy (ICC = 0.880; SEM = 0.263; MD = 0.728; p < 0.001) and 'Moderate' for sensibility (ICC = 0.617; SEM = 0.648; MD = 1.797; p < 0.001) and awareness (ICC = 0.593; SEM = 0.227; MD = 0.628; p < 0.001). The absolute reliability shows low threshold values for observing true effects in HTT outcomes. The results also showed that reducing the number of HTT blocks did not impact the outcomes. The HTT showed to be reliable in determine the interoceptive competences in healthy adults.

Ice Massage on the Calf Improves 4-km Running Time Trial Performance in a Normothermic Environment.

Purpose: Local cooling with ice massage is a practical and inexpensive technique to decrease perceptual stress and improve motor performance in hot environments. However, it is unknown whether local cooling with ice massage reduces perceptual responses to exercise and improves performance in a normothermic environment. Thus, we investigated whether ice massage on the calf muscles before a 4 km running time trial (TT4km) reduced the ratings of perceived exertion (RPE) and perceived muscle pain, thereby improving exercise performance in a normothermic environment. Methods: After familiarizations, fourteen recreationally endurance-trained men (age = 21.3 ± 1.2 years; body weight = 67.5 ± 9.2 kg; height = 173.0 ± 5.0 cm) underwent two TT4km on a 400 m track in normothermic conditions with or without ice massage before the trial. The time of running, RPE, and pain perception were recorded every 400 m throughout the TT4km. Results: The local cooling with ice massage increased the mean speed (~ 5.2%, p = 0.03) and decreased the time to complete the TT4km (~ 5.5%, p = 0.03). Accordingly, ice massage also reduced the exercise-derived pain perception (p = 0.028), although no effect has been found in the RPE during the TT4km (p = 0.32). Conclusion: Together, these results showed that local cooling with ice massage before the exercise reduced the exercise-derived pain perception, enabling runners to increase the speed for a comparable RPE during exercise, thereby improving the TT4km performance in a normothermic environment.

Linear and undulating resistance training programming induce similar outcomes on physical fitness in elderly women / Programações linear e ondulatória do treinamento de força induzem a mesmos resultados na aptidão física em mulheres idosas

Abstract The aim of the present study was to analyze the effect of two different types of resistance training programming (linear and daily undulating) on submaximal strength and functional capacity in elderly women. Twenty-two participants (64 ± 3 years) were randomly assigned to 2 training groups: linear programming (LP; n=12) and daily undulating programming (DUP; n =10). Functional capacity and submaximal strength (10RM) were analyzed before and after 12 weeks of resistance training. The results demonstrated improvement on strength and functional capacity after the resistance training period (p ≤ 0.05), except for the Bench Press (p = 0.30), for both groups DUP and LP. The Effect Size was, respectively, high for DUP (timed up and go test = -2.07, and timed sit test= 4.69), and high for LP (horizontal leg press = 2.35). For all other results, the effect size was trivial or small. No statistical difference was observed between programming models. The LP and DUP trainnings have similar results in increasing submaximal muscle strength in elderly women inexperienced in RT after 12 weeks of intervention (p ≤ 0,05). However, DUP appears to be more effective in increasing functional capacity. In practice, the professional can use both the LP and the DUP to improve the level of fitness in the early stages of training in this population. However, when the goal of programming is to increase functional capacity, DUP can be prioritized.

Resumo O objetivo do presente estudo foi analisar o efeito de dois tipos diferentes de programação do treinamento de força (linear e ondulatório diário) na força submáxima e na capacidade funcional de mulheres idosas. Vinte e duas participantes (64 ± 3 anos) foram randomizados em 2 grupos experimentais: programação linear (PL; n=12) e programação ondulatória diária (POD; n=10). A capacidade funcional e a força submáxima (10RM) foram avaliadas antes e depois das 12 semanas de treinamento de força. Os resultados demonstraram melhora da força submáxima e da capacidade funcional após o período de treinamento (p ≤ 0,05), exceto para o exercício supino (p = 0,30), para ambos os grupos POD e PL. Foi encontrado um tamanho de efeito grande para a POD nos testes de sentar e caminhar = -2,07 e teste de sentar e levantar = 4,69, bem como na PL para o exercício leg press horizontal = 2,35. Não foi observada diferença estatística entre os modelos de programação. As programações LP e DUP têm resultados semelhantes no aumento da força muscular submáxima em mulheres idosas inexperientes em TR após 12 semanas de intervenção (p ≤ 0,05). No entanto, o DUP parece ser mais eficaz para aumentar a capacidade funcional. Na prática, o profissional pode usar tanto o LP quanto o DUP para melhorar o nível de condicionamento físico nos estágios iniciais do treinamento nessa população. Porém, quando o objetivo da programação é aumentar a capacidade funcional, o DUP pode ser priorizado.

Comparison of the autonomic nervous system dysfunction between different chronic spine disorders: neck pain versus low back pain.

OBJECTIVE: This study aims to compare heart rate variability (HRV) between patients with chronic neck pain and patients with chronic low back pain and to correlate the chronic pain variables with heart rate variability indices. METHODS: This is a cross-sectional study. We divided the sample into two groups: neck pain (n=30) and low back pain (n=30). We used the Numeric Pain Rating Scale, Neck Disability Index, Roland-Morris Disability Questionnaire, Pain-Related Catastrophizing Thoughts Scale, Tampa Scale of Kinesiophobia, and Pain Self-Efficacy Questionnaire. For heart rate variability analysis, we used the following indices: mean RR, standard deviation of all RR intervals, mean heart rate, root mean square differences of successive RR intervals, triangular index, triangular interpolation of the interval histogram, low-frequency band in arbitrary units and in absolute values, high-frequency band in arbitrary units and in absolute values, standard deviation of the instantaneous beat-to-beat variability (standard deviation 1), long-term standard deviation of continuous RR intervals (standard deviation 2), and Stress Index. We used Student's t-test for comparisons and Spearman's coefficient for correlations. RESULTS: We observe insignificant values in the differences between the groups. Disability and self-efficacy were correlated with heart rate variability only in patients with chronic neck pain, whereas catastrophizing and kinesiophobia showed greater correlations with heart rate variability in patients with chronic low back pain. CONCLUSIONS: Autonomic dysfunction of individuals with chronic neck pain, when compared to patients with chronic low back pain, does present insignificant differences.

Comparison of the autonomic nervous system dysfunction between different chronic spine disorders: neck pain versus low back pain

SUMMARY OBJECTIVE: This study aims to compare heart rate variability (HRV) between patients with chronic neck pain and patients with chronic low back pain and to correlate the chronic pain variables with heart rate variability indices. METHODS: This is a cross-sectional study. We divided the sample into two groups: neck pain (n=30) and low back pain (n=30). We used the Numeric Pain Rating Scale, Neck Disability Index, Roland-Morris Disability Questionnaire, Pain-Related Catastrophizing Thoughts Scale, Tampa Scale of Kinesiophobia, and Pain Self-Efficacy Questionnaire. For heart rate variability analysis, we used the following indices: mean RR, standard deviation of all RR intervals, mean heart rate, root mean square differences of successive RR intervals, triangular index, triangular interpolation of the interval histogram, low-frequency band in arbitrary units and in absolute values, high-frequency band in arbitrary units and in absolute values, standard deviation of the instantaneous beat-to-beat variability (standard deviation 1), long-term standard deviation of continuous RR intervals (standard deviation 2), and Stress Index. We used Student's t-test for comparisons and Spearman's coefficient for correlations. RESULTS: We observe insignificant values in the differences between the groups. Disability and self-efficacy were correlated with heart rate variability only in patients with chronic neck pain, whereas catastrophizing and kinesiophobia showed greater correlations with heart rate variability in patients with chronic low back pain. CONCLUSIONS: Autonomic dysfunction of individuals with chronic neck pain, when compared to patients with chronic low back pain, does present insignificant differences.

Fear of Return to Sport Scale (FRESS): a new instrument for use in injured professional or recreational athletes in rehabilitation.

Objective: To create, develop, and validate the Fear of Return to Sport Scale (FRESS) for injured professional or recreational athletes in rehabilitation. Methods: This is a questionnaire validation study. To determine the structural and construct validity, 192 injured professional or recreational athletes of different sports modalities were included. We used a subsample with 32 participants to analyze test-retest reliability and internal consistency. Main outcome measures were the FRESS, Numerical Pain Scale (NPS), Pain-Related Catastrophizing Thoughts Scale (PCTS), Self-Estimated Functional Inability because of Pain Questionnaire for athletes (SEFIP-sport), and Hospital Anxiety and Depression Scale (HADS). Results: Initially, 25 questions were proposed by the specialists. Of these, 4 questions were excluded due to similarity with others. After applying the content validity coefficient, 8 questions were excluded for presenting a value lower than 0.80, leaving 13 items. The exploratory factor analysis identified the one-dimensional structure of the FRESS with 13 items. However, five items were excluded for presenting high covariance with the error of several other FRESS items in the confirmatory factor analysis. Thus, the final version of the FRESS was defined with one domain and eight items. Regarding the construct validity, we observed a magnitude of correlation varying between 0.257 and 0.470 between the FRESS and the instruments used here. We observed adequate test-retest reliability (intraclass correlation coefficient = 0.896) and internal consistency (Cronbach's alpha = 0.868). Ceiling and floor effects were not observed. Conclusion: The FRESS with one domain and eight items has acceptable measurement properties and its use in clinical and sports environments to measure the fear of returning to sport in injured professional or recreational athletes is supported. Supplementary Information: The online version contains supplementary material available at 10.1007/s11332-022-00975-4.

The reward for placebos: mechanisms underpinning placebo-induced effects on motor performance.

Different from the most popular thinking, the placebo effect is not a purely psychological phenomenon. A body of knowledge from multidisciplinary fields has shown that the expectation of a potential benefit when receiving a treatment induces a cascade of neurochemical-electrophysiological alterations in brain reward areas, including motor-related ones. Alterations in the dopamine, opioid, and glutamate metabolism are the neural representation converting reward-derived declarative forms into an attractive and wanted behavior, thereby changing the activation in reward subcortical and cortical structures involved in motor planning, motor execution, and emotional-cognitive attributes of decision-making. We propose that the expectation of receiving a treatment that is beneficial to motor performance triggers a cascade of activations in brain reward areas that travels from motor planning and motor command areas, passing through corticospinal pathways until driving the skeletal muscles, therefore facilitating the motor performance. Although alternative explanations cannot be totally ruled out, this mechanistic route is robust in explaining the results of placebo-induced effects on motor performance and could lead to novel insights and applications in the exercise sciences. Factors such as sex differences in reward-related mechanisms and aversion-induced nocebo effects should also be addressed.

A Narrative Review of Current Concerns and Future Perspectives of the Carbohydrate Mouth Rinse Effects on Exercise Performance.

Previous systematic reviews have confirmed that carbohydrate (CHO) mouth rinse may boost physical exercise performance, despite some methodological aspects likely affecting its ergogenic effect. In this review, we discussed if the exercise mode, pre-exercise fasting status, CHO solutions concentration, CHO solutions temperature, mouth rinse duration, and CHO placebo effects may potentially reduce the CHO mouth rinse ergogenic effect, suggesting possible solutions to manage these potential confounders. The effectiveness of CHO mouth rinse as a performance booster is apparently related to the origin of the exercise-induced neuromuscular fatigue, as CHO mouth rinse unequivocally potentiates endurance rather than sprint and strength exercises performance. Furthermore, ergogenic effects have been greater in fasting than fed state, somehow explaining the varied magnitude of the CHO mouth rinse effects in exercise performance. In this regard, the CHO solution concentration and temperature, as well as the mouth rinse duration, may have increased the variability observed in CHO mouth rinse effects in fasting and fed state. Finally, placebo effects have challenged the potential of the CHO mouth rinse as an ergogenic aid. Therefore, we suggest that future studies should consider methodological controls such as sample size and sample homogeneity, proper familiarization with experimental procedures, and the use of alternative placebo designs to provide unbiased evidence regarding the potential of the CHO mouth rinse as an ergogenic aid.

The Effect of Low-intensity Aerobic Training Combined with Blood Flow Restriction on Maximal Strength, Muscle Mass, and Cycling Performance in a Cyclist with Knee Displacement.

Low-intensity aerobic training combined with blood flow restriction (LI + BFR) has resulted in increases in aerobic and neuromuscular capacities in untrained individuals. This strategy may help cyclists incapable of training with high intensity bouts or during a rehabilitation program. However, there is a lack of evidence about the use of LI + BFR in injured trained cyclists. Thus, we investigated the effects of LI + BFR on aerobic capacity, maximal isometric strength, cross-sectional area of vastus lateralis (CSAVL), time to exhaustion test (TTE), and 20 km cycling time-trial performance (TT20 km) in a male cyclist with knee osteoarthritis (OA). After a 4-week control period, a 9-week (2 days/week) intervention period started. Pre- and post-intervention TT20 km, peak oxygen consumption (VO2peak), power output of the 1st and 2nd ventilatory thresholds (1st WVT and 2nd WVT), maximum power output (Wmax), TTE, muscle strength and CSAVL of both legs were measured. Training intensity was fixed at 30% of Wmax while the duration was progressively increased from 12 min to 24 min. There was a reduction in time to complete TT20 km (-1%) with increases in TT20 km mean power output (3.9%), VO2peak (11.4%), 2nd WVT (8.3%), Wmax (3.8%), TTE (15.5%), right and left legs maximal strength (1.3% and 8.5%, respectively) and CSAVL (3.3% and 3.7%, respectively). There was no alteration in 1st WVT. Based on the results, we suggest that LI + BFR may be a promising training strategy to improve the performance of knee-injured cyclists with knee OA.