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Objectives: To determine the test-retest reliability and agreement of home-based functional capacity self-administered assessments in socially isolated older adults., Methods: Fourteen community-dwelling older adults (eight females, 67.9 ± 7.7 years) volunteered for this study. Before testing, participants were screened online for eligibility and received instructional videos explaining test set-up and execution. Participants underwent the 30-second sit-to-standing test, gait speed tests at the usual pace, and timed-up-and-go tests administered 4 weeks apart. For the 30-second sit-to-standing protocol, participants were instructed to repeatedly sit and stand from a chair (with a height of ∼ 43 cm and without armrests) for 30 s, with the number of repetitions recorded. In the gait speed test protocol, participants were instructed to walk at their usual and comfortable pace, with the time taken recorded (seconds). In the timed-up-and-go, participants stood up from a chair, walked as fast as possible for 3 m, circled a marked point, and returned to the chair to sit down, completing the test, with the score recorded (seconds). A trained researcher conducted the scoring virtually via synchronous video., Results: 30-second sit-to-standing, gait speed test, and timed-up-and-go showed excellent mean coefficient of variation values (2.0-4.9), small standard error of measurement (0.08-1.27), excellent intraclass coefficient (0.97-0.99), very strong correlations (0.97-0.99) and good agreement between the two days of testing., Conclusion: Self-administered functional capacity tests performed by older adults at home were reliable with good agreement. Healthcare professionals and older adults should take advantage of simple remote self-administered assessments performed at home to evaluate older adults' health status., Competing Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2024.)

Galls (also known as cecidia) have been studied by botanists, zoologists and microbiologists over the last century. Indeed, galls can be induced by different animals, bacteria, viruses and fungi, so that their presence simultaneously attested the presence of specific host plants and gall-inducing species. Consequently, gall collections, also known as cecidological herbaria or cecidological collections, can be interesting to study biodiversity changes over time. This review describes the main cecidological collections currently available in different European museums in order to stimulate their future study. The present analysis suggests that well-organized and preserved cecidological collections have great potential to guide research in taxonomy and systematics. Furthermore, this review aims to encourage future research on the conservation and digitisation standards of gall specimens in order to make cecidological data more accessible to researchers.

Background: Exercise oscillatory ventilation (EOV) is characterized by periodic oscillations of minute ventilation during cardiopulmonary exercise testing (CPET). Despite its prognostic value in chronic heart failure (HF), its diagnosis is complex due to technical limitations. An easier and more accurate way of EOV identification can contribute to a better approach and clinical diagnosis. This study aims to describe a software development to standardize the EOV diagnosis from CPET's raw data in heart failure patients and test its reliability (intra- and inter-rater)., Methods: The software was developed in the "drag-and-drop" G-language using LabVIEW ® . Five EOV definitions (Ben-Dov, Corrà, Kremser, Leite, and Sun definitions), two alternative approaches, one smoothing technique, and some basic statistics were incorporated into the interface to visualize four charts of the ventilatory response. EOV identification was based on a set of criteria verified from the interaction between amplitude, cycle length, and oscillation time. Two raters analyzed the datasets. In addition, repeated measurements were verified after six months using about 25% of the initial data. Cohen's kappa coefficient (κ) was used to investigate the reliability., Results: Overall, 391 tests were analyzed in duplicate (inter-rater reliability) and 100 tests were randomized for new analysis (intra-rater reliability). High inter-rater (κ > 0.80) and intra-rater (κ > 0.80) reliability of the five EOV diagnoses were observed., Conclusion: The present study proposes novel semi-automated software to detect EOV in HF, with high inter and intra-rater agreements. The software project and its tutorial are freely available for download., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: Cardiopulmonary exercise testing (CPET) is the gold standard for analyzing cardiorespiratory fitness and integrating physiological responses. However, the presence of chronic diseases may compromise cerebral hemodynamic responses during CPET. In addition, the acute response of cerebral oxygenation during incremental CPET may identify abnormal behavior and ensure greater safety for patients with cardiovascular, respiratory, and metabolic diseases., Objective: To summarize the cerebral oxygenation acute response during CPET of patients with cardiovascular, metabolic, or respiratory diseases., Methods: From inception to 23rd September 2022, five databases (PubMed, SCOPUS, Web of Science, Embase and CINAHAL) were searched for cross-sectional studies performing incremental CPET and measuring the cerebral oxygenation acute response in cardiovascular, metabolic, or respiratory diseases compared with healthy individuals. The Downs and Black tool assessed the risk of bias of the studies., Results: We included seven studies with 428 participants (305 men and 123 women), aged 43 to 70 years. Of these, 101 had heart failure NYHA II and III; 77 idiopathic dilated cardiomyopathy; 33 valvular disease; 25 coronary heart disease; 22 pulmonary arterial hypertension; 15 had severe obstructive sleep apnea (OSA) and 166 were apparently healthy. There was no eligible article with metabolic disease. There was a lower magnitude increase in cerebral oxygenation of cardiovascular patients compared with the healthy individuals during the CPET. Furthermore, pulmonary arterial hypertension patients presented increased cerebral oxygen extraction, differently to those with severe OSA., Conclusion: Considering the heterogeneity of the included studies, patients with cardiovascular disease may suffer from reduced cerebral oxygen supply, and individuals with OSA presented lower brain oxygen extraction during the CPET. Future studies should aim for strategies to improve cerebral oxygenation to ensure greater safety at CPET of cardiovascular and OSA patients. An acute response pattern for metabolic and other respiratory diseases was not established., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Cardiopulmonary exercise testing (CPET) is a non-invasive approach to measure the maximum oxygen uptake ([Formula: see text]), which is an index to assess cardiovascular fitness (CF). However, CPET is not available to all populations and cannot be obtained continuously. Thus, wearable sensors are associated with machine learning (ML) algorithms to investigate CF. Therefore, this study aimed to predict CF by using ML algorithms using data obtained by wearable technologies. For this purpose, 43 volunteers with different levels of aerobic power, who wore a wearable device to collect unobtrusive data for 7 days, were evaluated by CPET. Eleven inputs (sex, age, weight, height, and body mass index, breathing rate, minute ventilation, total hip acceleration, walking cadence, heart rate, and tidal volume) were used to predict the [Formula: see text] by support vector regression (SVR). Afterward, the SHapley Additive exPlanations (SHAP) method was used to explain their results. SVR was able to predict the CF, and the SHAP method showed that the inputs related to hemodynamic and anthropometric domains were the most important ones to predict the CF. Therefore, we conclude that the cardiovascular fitness can be predicted by wearable technologies associated with machine learning during unsupervised activities of daily living., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Frade et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Aims: To evaluate the heart rate fragmentation (HRF) of type 2 diabetes mellitus (T2DM) patients and its relationship with heart rate variability (HRV) indices., Methods: One hundred sixty-four men, aged 47-57 years were retrospectively analyzed from a database. Participants were T2DM (n = 82) and apparently healthy (n = 82). R-R interval time series recorded by electrocardiogram were collected at the supine position for 10 to 15 min. From HRF, the percentage of inflection points (PIP), percentage of words with zero, one, two, or three inflections points (W 0 , W 1 , W 2 , W 3 ), and percentage with only type hard, soft, or mixed inflections points type (W H , W S , W M ) were quantified., Results: T2DM presented higher PIP, W S , W M and W 3 , while W H and W 1 was lower compared with healthy (p < 0.05). Moreover, a positive moderate correlation was found between W H and root mean square of the successive R-R differences (RMSSD) and high frequency (HF) indices. In contrast, a negative moderate correlation was found between W S and W M with RMSSD and HF indices., Conclusions: T2DM have increased fragmentation patterns, and words grouped by inflection type are more closely related to HRV. The HRF approach might be useful to assess heart rate dynamic abnormalities in males with type 2 diabetes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Different exercise models have been used in patients with type 2 diabetes mellitus (T2D), like moderate intensity continuous training (MICT) and high intensity interval training (HIIT); however, their effects on autonomic modulation are unknown. The present study aimed to compare the effects of different exercise modes on autonomic modulation in patients with T2D. In total, 44 adults with >5 years of T2D diagnosis were recruited and stratified into three groups: HIIT-30:30 ( n = 15, age 59.13 ± 5.57 years) that performed 20 repetitions of 30 s at 100% of VO2peak with passive recovery, HIIT-2:2 ( n = 14, age 61.20 ± 2.88) that performed 5 repetitions of 2 min at 100% of VO2peak with passive recovery, and MICT ( n = 15, age 58.50 ± 5.26) that performed 14 min of continuous exercise at 70% of VO2peak. All participants underwent anamnesis and evaluation of cardiorespiratory fitness and cardiac autonomic modulation. All protocols were equated by total distance and were performed two times per week for 8 weeks. Group × time interactions were observed for resting heart rate (HRrest) [F(2.82) = 3.641; p = 0.031] and SDNN [F(2.82) = 3.462; p = 0.036]. Only the HIIT-30:30 group significantly reduced SDNN ( p = 0.002 and 0.025, respectively). HRrest reduced more in the HIIT-30:30 group compared with the MICT group ( p = 0.038). Group × time interactions were also observed for offTAU [F(2.82) = 3.146; p = 0.048] and offTMR [F(2.82) = 4.424; p = 0.015]. The MICT group presented increased values of offTAU compared with the HIIT-30:30 and HIIT-2:2 groups ( p = 0.001 and 0.013, respectively), representing a slower HR response after eight weeks of intervention. HIIT, specially HIIT-30:30, represents a promising measure for improving autonomic modulation in patients with T2D.

Introduction: Type 2 diabetes (T2D) is characterized by a metabolic disorder that elevates blood glucose concentration. Chronic hyperglycemia has been associated with several complications in patients with T2D, one of which is cardiac autonomic dysfunction that can be assessed from heart rate variability (HRV) and heart rate recovery (HRR) response, both associated with many aspects of health and fitness, including severe cardiovascular outcomes., Objective: To evaluate the effects of T2D on cardiac autonomic modulation by means of HRV and HRR measurements., Materials and Methods: This study has an observational with case-control characteristic and involved ninety-three middle-aged adults stratified into two groups (control group - CG, n = 34; diabetes group - DG, n = 59). After signing the free and informed consent form, the patients were submitted to the evaluation protocols, performed biochemical tests to confirm the diagnosis of T2D, collection of R-R intervals for HRV analysis and cardiopulmonary effort test to quantify HRR., Results: At rest, the DG showed a reduction in global HRV (SDNN= 19.31 ± 11.72 vs CG 43.09 ± 12.74, p < 0.0001), lower parasympathetic modulation (RMSSD= 20.49 ± 14.68 vs 52.41 ± 19.50, PNN50 = 4.76 ± 10.53 vs 31.24 ± 19.24, 2VD%= 19.97 ± 10.30 vs 28.81 ± 9.77, p < 0.0001 for both indices) and higher HRrest when compared to CG. After interruption of physical exercise, a slowed heart rate response was observed in the DG when compared to the CG. Finally, a simple linear regression showed that fasting glycemia was able to predict cardiac autonomic involvement in volunteers with T2D., Conclusion: Patients with T2D presented lower parasympathetic modulation at rest and slowed HRR after physical exercise, which may be associated with higher cardiovascular risks. The findings show the glycemic profile as an important predictor of impaired cardiac autonomic modulation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Silva, Gentil, Seguro, de Oliveira, Silva, Zamunér, Beltrame and Rebelo.)

The aim of this study was to characterise the cardiac autonomic modulation of different office tasks performed by office workers with access to a sit-stand table. Heart rate variability (HRV) of 24 office workers was measured for two hours during three days in the last week of sit-stand table use. HRV indexes and the percentage of heart rate reserve (%HRR) were calculated during computer and non-computer work tasks while sitting or standing, non-computer tasks away from the work desk, and informal work breaks. All cardiac autonomic responses demonstrated a statistically significant interaction effect between the tasks (all p  < 0.05) except for the logarithmically-transformed high frequency power (ln HF ms 2 ; p  = 0.14). Tasks performed while standing and away from the desk had higher sympathetic modulation; in addition, the observed higher %HRR demonstrated that these tasks were more physically demanding in comparison to other tasks. Practitioner Summary: Prior reports indicated benefits based on alternated body postures using sit-stand table. Nevertheless, the cardiac autonomic responses of different tasks performed by office workers are unknown. This cross-sectional study showed that different tasks stimulate the cardiac autonomic nervous system in different ways, which could bring positive effects to the cardiovascular system.

Objective: To investigate cerebral oxygenation (Cox) responses as well as respiratory (Res) and active peripheral muscle (Pm) O 2 delivery during high-intensity cycling exercise and contrast responses between patients with coexistent chronic obstructive pulmonary disease (COPD)-heart failure (HF) and HF alone., Methods: Cross-sectional study involving 11 COPD-HF and 11 HF patients. On two different days, patients performed maximal incremental cardiopulmonary exercise testing (CPET) and constant load exercise on a cycle ergometer until the limit of tolerance (Tlim). The high-intensity exercise session was 80% of the peak CPET work rate. Relative blood concentrations of oxyhemoglobin ([O 2 Hb]), deoxyhemoglobin ([HHb]) of Res, Pm (right vastus lateralis) and Cox (pre-frontal) were measured using near infrared spectroscopy., Results: We observed a greater decrease in [O 2 Hb] at a lower Tlim in COPD-HF when compared to HF (P < 0.05). [HHb] of Res was higher (P < 0.05) and Tlim was lower in COPD-HF vs. HF. Pm and Cox were lower and Tlim was higher in (P < 0.05) HF vs. COPD-HF. In HF, there was a lower ∆[O 2 Hb] and higher ∆ [HHb] of Pm when contrasted to Cox observed during exercise, as well as a lower ∆ [O 2 Hb] and higher ∆ [HHb] of Res when contrasted with Cox (P < 0.05). However, COPD-HF patients presented with a higher ∆ [HHb] of Res and Pm when contrasted with Cox (P < 0.05)., Conclusion: The coexistence of COPD in patients with HF produces negative effects on Cox, greater deoxygenation of the respiratory and peripheral muscles and higher exertional dyspnea, which may help to explain an even lower exercise tolerance in this multimorbidity phenotype., Competing Interests: Declaration of Competing Interest No potential conflict of interest was reported by the authors., (Copyright © 2020 Elsevier Inc. All rights reserved.)

This study investigated the relationship between repeated-sprint ability, aerobic capacity, and oxygen uptake kinetics during the transition between exercise and recovery (off-transient) in female athletes of an intermittent sport modality. Eighteen professional soccer players completed three tests: 1) a maximal incremental exercise test; 2) a constant speed time-to-exhaustion test; and 3) a repeated-sprint ability test consisting of six 40-m sprints with 20 s of passive recovery in-between. Correlations between time-to-exhaustion, repeated-sprint ability, and oxygen uptake kinetics were calculated afterwards. The level of significance was set at p < 0.05. A performance decrement during repeated-sprint ability was found to be related to: 1) time-to-exhaustion (e.g., exercise tolerance; r = -0.773, p < 0.001); 2) oxygen uptake recovery time (r = 0.601, p = 0.008); and 3) oxygen uptake mean response time of recovery (r = 0.722, p < 0.001). Moreover, the best sprint time (r = -0.601, p = 0.008) and the mean sprint time (r = -0.608, p = 0.007) were found to be related to maximal oxygen uptake. Collectively, these results reinforce the relation between oxygen uptake kinetics and the ability to maintain sprint performance in female athletes. These results may contribute to coaches and training staff of female soccer teams to focus on training and improve their athletes' aerobic capacity and recovery capacity to improve intermittent exercise performance., (© 2020 Bruno Archiza, Daniela K. Andaku, Thomas Beltrame, Cleiton A. Libardi, Audrey Borghi-Silva, published by Sciendo.)

Efforts to better understand cardiorespiratory health are relevant for the future development of optimized physical activity programs. We aimed to explore the impact of the signal quality on the expected associations between the ability of the aerobic system in supplying energy as fast as possible during moderate exercise transitions with its maximum capacity to supply energy during maximal exertion. It was hypothesized that a slower aerobic system response during moderate exercise transitions is associated with a lower maximal aerobic power; however, this relationship relies on the quality of the oxygen uptake data set. Forty-three apparently healthy participants performed a moderate constant work rate (CWR) followed by a pseudorandom binary sequence (PRBS) exercise protocol on a cycle ergometer. Participants also performed a maximum incremental cardiopulmonary exercise testing (CPET). The maximal aerobic power was evaluated by the peak oxygen uptake during the CPET, and the aerobic fitness was estimated from different approaches for oxygen uptake dynamics analysis during the CWR and PRBS protocols at different levels of signal-to-noise ratio. The product moment correlation coefficient was used to evaluate the correlation level between variables. Aerobic fitness was correlated with maximum aerobic power, but this correlation increased as a function of the signal-to-noise ratio. Aerobic fitness is related to maximal aerobic power; however, this association appeared to be highly dependent on the data quality and analysis for aerobic fitness evaluation. Our results show that simpler moderate exercise protocols might be as good as maximal exertion exercise protocols to obtain indexes related to cardiorespiratory health. NEW & NOTEWORTHY Optimized methods for cardiorespiratory health evaluation are of great interest for public health. Moderate exercise protocols might be as good as maximum exertion exercise protocols to evaluate cardiorespiratory health. Pseudorandom or constant workload moderate exercise can be used to evaluate cardiorespiratory health.

Exposure of biological tissue to photobiomodulation therapy (PBMT) seems to increase the oxygen availability and mitochondrial electrochemical activity. With the advancement of new technologies, such as near-infrared spectroscopy (NIRS), information can be obtained about the balance between oxygen utilization and delivery by assessing local oxy- ([O 2 Hb]) and deoxy-myohemoglobin ([HHb]) concentrations, both measured in micromolars (μM). Consequently, NIRS can be used to study ("in vivo") PBMT effects on the oxidative system, including oxygen availability. Thus, the main objective of the present study was to use NIRS to investigate the acute effects of PBMT by light-emitting diode (LED) on the oxygen delivery and utilization in humans. Twelve healthy young participants were treated with a LED device (850 nm, 50 mW, 2 J) and placebo applied over the proximal third of the flexor carpi ulnaris muscle of the left or right forearm selected in a random order. The LED was applied in direct contact with skin and the device was switched on for 40 s in 4 different interventions (I 1 , I 2 , I 3 and I 4 ) with a 3-min interval between interventions. The placebo condition was considered as the period before the first PBMT. The NIRS device was used to evaluate the relative changes in [O 2 Hb] and [HHb] before and after placebo and interventions. We found that PBMT statistically increased the [O 2 Hb] in 0.39 μM. These results demonstrate the potential of PBMT to increase oxygen availability.

To evaluate the photobiomodulation (PBM) effect on the cardiovascular autonomic control, analyzed by baroreflex sensitivity (sequence method), during constant load exercise and recovery in diabetic men, we evaluated 11 men with type 2 diabetes (DM2) (40-64 years). The constant workload exercise protocol (TECC) was performed on two different days, 14 days apart from each other, to guarantee PBM washout period. After PBM by light-emitting diode (LED) irradiation (150 J or 300 J or placebo), 10 min of rest (REST) was performed. After this period, the volunteer was positioned on a cycloergometer to start the test (1-min rest, 3-min free-load heating, 6-min constant workload-EXERCISE, 6-min free-load cool-down, 1-min rest) followed by a sitting period of 10 min (RECOVERY). The constant workload corresponded to 80%VO 2GET (gas exchange threshold) identified by a previous cardiopulmonary exercise test (CPET). PBM was applied in continuous mode, contact technique, bilaterally, on both femoral quadriceps and gastrocnemius muscle groups. The electrocardiogram R-R intervals (BioAmp FE132) and the peripheral pulse pressure signals (Finometer PRO) were collected continuously throughout the protocol. Stable sequences of 256 points were chosen at REST, EXERCISE, and RECOVERY. The baroreflex sensitivity (BRS) was computed in time domain according to the sequence method (α seq ). The comparison between therapies (150 J/300 J/placebo) and condition (REST, EXERCISE, and RECOVERY) was performed using the ANOVA two-way repeated measures test. There was no interaction between therapy and conditions during the TECC. There was only the condition effect (p < 0.001), showing that the behavior of α seq was similar regardless of the therapy. Photobiomodulation with 150 J or 300 J applied previously to a moderate-intensity TECC in DM2 was not able to promote cardiovascular autonomic control changes leading to an improvement in BRS.

Background: There are few reports in the literature supporting the understanding of the physiological mechanisms of intolerance in patients with COPD to perform unsupported upper limb activities. The aims of this study were to quantify the electrical activity and oxygenation of inspiratory and upper limb muscles, and to investigate whether electromyographic manifestations of muscle fatigue are related to upper limb function as assessed by the 6-min pegboard and ring test (6PBRT) in subjects with COPD and in healthy subjects., Methods: Thirty subjects with COPD (FEV 1 42.1 ± 16.4% predicted; 68.0 ± 7.6 y old) comprised the COPD group, and 34 healthy subjects (66.8 ± 8.0 y old) comprised the control group. Both groups were assessed for body composition with dual-energy radiograph absorptiometry and spirometry. The 6PBRT was performed with simultaneous assessment of electromyography, near-infrared spectroscopy, and gas analyses (expiratory minute volume)., Results: Differences were observed between groups for performance (number of rings) in the 6PBRT, with the COPD group achieving lower values than the control group ( P < .001). The ventilatory demand (expiratory minute volume/maximum voluntary ventilation) and root mean square amplitude of the sternocleidomastoid muscle were higher in the COPD group than in the control group ( P < .04). Lower values for oxyhemoglobin and total hemoglobin were found in intercostal muscles of the COPD group compared to the control group. The root mean square amplitude of the intercostal muscles was lower in the COPD group, while it was similar between groups for anterior deltoid and trapezius muscles. Median frequency of anterior deltoid muscles presented a decreased in both groups., Conclusions: Our results indicate that the 6PBRT was performed at a higher electrical activity in the accessory inspiratory muscles, such as the sternocleidomastoid muscle, and a lower oxygenation profile in the intercostal muscles in subjects with COPD compared with healthy controls, but without muscle fatigue signs. These findings suggest that the higher ventilatory demand presented in subjects with COPD could have contributed to the worse performance in this group without signals of peripheral muscle limitation., (Copyright © 2020 by Daedalus Enterprises.)

The aim of this study was to compare the heart rate (HR) dynamics and variability before and after high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) protocols with workloads based on treadmill workload at which maximal oxygen uptake was achieved ( WL V ˙ O 2 max ) . Ten participants performed cardiopulmonary exercise testing (CPET) to obtain oxygen uptake ( WL V ˙ O 2 max ) . All training protocols were performed on a treadmill, with 0% grade, and had similar total distance. The MICT was composed by 21 min at 70% of WL V ˙ O 2 max . The first HIIT protocol (HIIT-30 : 30) was composed by 29 repetitions of 30 s at 100% of s V ˙ O 2 max and the second HIIT protocol (HIIT-4 : 3) was composed by three repetitions of 4 min at 90% of WL V ˙ O 2 max . Before, during and after each training protocol, HR dynamics and variability (HRV) were analysed by standard kinetics and linear (time and frequency domains). The repeated measures analysis of variance indicated that the HR dynamics, which characterizes the speed of HR during the rest to exercise transition, was statistically ( p < 0.05) slower during MICT in comparison to both HIIT protocols. The HRV analysis, which characterizes the cardiac autonomic modulation during the exercise recovery, was statistically higher in HIIT-4 : 3 in comparison to MICT and HIIT-30 : 30 protocols ( p < 0.005 and p = 0.012, respectively), suggesting that the HIIT-4 : 3 induced higher sympathetic and lower parasympathetic modulation during exercise in comparison to the other training protocols. In conclusion, HIIT-4 : 3 demonstrated post-exercise sympathetic hyperactivity and a higher HRpeak, while the HIIT-30 : 30 and MICT resulted in better HRV and HR in the exercise-recovery transition. The cardiac autonomic balance increased in HIIT-30 : 30 while HIIT-4 : 3 induced sympathetic hyperactivity and cardiac overload., Competing Interests: We declare that there is no conflict of interest., (© 2019 The Authors.)

The aim of this study was to evaluate the acute effects of light-emitting diode therapy (LEDT) on cardiopulmonary adjustments and muscle oxygenation dynamics during transition to moderate exercise, as well as in glucose and lactate levels in patients with type 2 diabetes mellitus (T2DM). Sixteen individuals with T2DM (age 55.1±5.4 years) performed four separate tests receiving LEDT or placebo in random order, at intervals of at least 14 days. A light-emitting diode array (50GaAIAs LEDs, 850nm, 75mW per diode) was used to perform LEDT bilaterally on the quadriceps femoris and triceps surae muscles for 40s at each site. After, a moderate cycling exercise was performed and oxygen uptake, muscular deoxyhemoglobin, heart rate and cardiac output were measured. Lactate and glucose levels were measured before LEDT/placebo and after the exercise. The LEDT decreased the glucose levels after the exercise compared with values before LEDT (173.7±61.0 to 143.5±53.5 mg/dl, P=0.02) and it did not affect the cardiopulmonary and hemodynamic adjustments in exercise, as well as lactate levels in both groups. In conclusion, the LEDT in combination with moderate exercise acutely decreased the glucose levels in men with T2DM., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Light-emitting diodes (LEDs) might have a beneficial impact on cytochrome-c oxidase enzyme activity. Thus, it was hypothesized that photobiomodulation by light-emitting diode therapy (LEDT) could influence aerobic metabolism dynamics. Possible LEDT-mediated aerobic improvements were investigated mainly by a precise characterization of the pulmonary O 2 uptake dynamics during moderate exercise transitions. Eight healthy young adults were enrolled in this randomized, double-blind, placebo-controlled, crossover study. A multi-diode array of LEDs was used for muscular pre-conditioning 30 min and 6 h before exercise testing. Pulmonary O 2 uptake, carbon dioxide output, cardiac output, heart rate, stroke volume, and total arteriovenous oxygen difference dynamics were evaluated by frequency domain analysis. Comparisons revealed no statistical (p > 0.05) differences between LEDT and placebo, suggesting no significant changes in aerobic system dynamics. These results challenge earlier publications that reported changes in pulmonary O 2 uptake during incremental exercise until exhaustion after LEDT. Perhaps, increments in peak pulmonary O 2 uptake after LEDT may be a consequence of higher exercise tolerance caused by non-aerobic-related factors as opposed to an improved aerobic response.

It is hypothesized that estradiol levels, as well as aging, influence cardiac autonomic function in women. The main aim of this study was to test the correlations between heart rate recovery (HRR) dynamics, as a proxy of cardiac autonomic function, with estradiol levels and age in women. This cross-sectional study involved 44 healthy women. Heart rate (HR) data were obtained beat-by-beat during the entire experiment. Maximal incremental exercise testing (IET) on a cycle ergometer was performed followed by 6 min of recovery. During the IET recovery period, the overall HRR dynamics were evaluated by exponential data modeling (time constant "τ") where shorter τ indicates faster HRR adjustment. Considering the cardiac autonomic complexity, HRR dynamics were also evaluated by delta (Δ) analysis considering different HR data intervals. The relationship between HRR dynamics, estradiol levels and age was tested by Pearson product-moment correlation. The overall HRR dynamics (i.e., τ) were statistically correlated with age ( r = 0.58, p < 0.001) and estradiol levels ( r = -0.37, p = 0.01). The Δ analysis showed that the slower overall HRR associated with aging was a consequence of slower dynamics occurring within the 45-210 s interval, indicating slower sympathetic withdrawal. In conclusion, aging effects on HRR in women seems to be correlated with a slower sympathetic withdrawal. In addition, the cardioprotective effect previously associated with estradiol seems not to influence the autonomic modulation during exercise recovery periods in women.

Physical activity levels are related through algorithms to the energetic demand, with no information regarding the integrity of the multiple physiological systems involved in the energetic supply. Longitudinal analysis of the oxygen uptake (V̇o 2 ) by wearable sensors in realistic settings might permit development of a practical tool for the study of the longitudinal aerobic system dynamics (i.e., V̇o 2 kinetics). This study evaluated aerobic system dynamics based on predicted V̇o 2 data obtained from wearable sensors during unsupervised activities of daily living (μADL). Thirteen healthy men performed a laboratory-controlled moderate exercise protocol and were monitored for ≈6 h/day for 4 days (μADL data). Variables derived from hip accelerometer (ACC HIP ), heart rate monitor, and respiratory bands during μADL were extracted and processed by a validated random forest regression model to predict V̇o 2 . The aerobic system analysis was based on the frequency-domain analysis of ACC HIP and predicted V̇o 2 data obtained during μADL. Optimal samples for frequency domain analysis (constrained to ≤0.01 Hz) were selected when ACC HIP was higher than 0.05 g at a given frequency (i.e., participants were active). The temporal characteristics of predicted V̇o 2 data during μADL correlated with the temporal characteristics of measured V̇o 2 data during laboratory-controlled protocol ([Formula: see text] = 0.82, P < 0.001, n = 13). In conclusion, aerobic system dynamics can be investigated during unsupervised activities of daily living by wearable sensors. Although speculative, these algorithms have the potential to be incorporated into wearable systems for early detection of changes in health status in realistic environments by detecting changes in aerobic response dynamics. NEW & NOTEWORTHY The early detection of subclinical aerobic system impairments might be indicative of impaired physiological reserves that impact the capacity for physical activity. This study is the first to use wearable sensors in unsupervised activities of daily living in combination with novel machine learning algorithms to investigate the aerobic system dynamics with the potential to contribute to models of functional health status and guide future individualized health care in the normal population.

Introduction: The objective of this study was to adapt the Brazilian version, and verify the validity, reliability and internal consistency of the Oliveira questionnaire on low back pain in young people., Material and Methods: The questionnaire was translated from European Portuguese into Brazilian Portuguese by means of translation and re-translation. The validity of the contents was determined by experts who analyzed the clarity and pertinence of the questions. Fifteen young people aged 15 to 18 took part in the pre-test step (qualitative analysis), 40 in the test-retest (reliability) and 679 in the evaluation of internal consistency. The intra-class correlation coefficient and Spearman's correlation coefficient were used in the reliability analysis (test-retest), and Cronbach's alpha to determine the internal consistency (stability)., Results: In the translation phase the questionnaire was modified and considered suitable, observing similarity and equivalence of the two versions. After being corrected by the experts in the validation of the contents, the instrument was considered suitable and valid, and in the pre-test, the young people suggested some modifications to make the questionnaire more succinct. With respect to reliability, the values for the intra-class correlation coefficient were between 0.512 - acceptable and 1 - excellent and Spearman's correlation coefficient varied between 0.525 and 1, classifying the instrument as reproducible. The internal consistency was considered acceptable with a 0.757 Cronbach's alpha., Discussion: The Oliveira questionnaire was choosen since it has been used in several Portuguese studies; moreover, it addresses the need to raise data regarding low back pain and associated risk factors., Conclusions: The Brazilian version of the Oliveira questionnaire on low back pain in young people showed valid and reliable cultural adaptation, with good reliability and stability.

Previous studies in children and older adults demonstrated faster oxygen uptake (V̇O 2 ) kinetics in males compared with females, but young healthy adults have not been studied. We hypothesized that young men would have faster aerobic system dynamics in response to the onset of exercise than women. Interactions between oxygen supply and utilization were characterized by the dynamics of V̇O 2 , deoxyhemoglobin (HHb), tissue saturation index (TSI), cardiac output (Q̇), and calculated arteriovenous O 2 difference (a-vO 2 diff ) in women and men. Eighteen healthy active young women and men (9 of each sex) with similar aerobic fitness levels volunteered for this study. Participants performed an incremental cardiopulmonary treadmill exercise test and 3 moderate-intensity treadmill exercise tests (at 80% V̇O 2 of gas exchange threshold). Data related to the moderate exercise were submitted to exponential data modelling to obtain parameters related to the aerobic system dynamics. The time constants of V̇O 2 , a-vO 2 diff , HHb, and TSI (30 ± 6, 29 ± 1, 16 ± 1, and 15 ± 2 s, respectively) in women were statistically (p < 0.05) faster than the time constants in men (42 ± 10, 49 ± 21, 19 ± 3, and 20 ± 4 s, respectively). Although Q̇ dynamics were not statistically different (p = 0.06) between groups, there was a trend to slower Q̇ dynamics in men corresponding with the slower V̇O 2 kinetics. These results indicated that the peripheral and pulmonary oxygen extraction dynamics were remarkably faster in women. Thus, contrary to the hypothesis, V̇O 2 dynamics measured at the mouth at the onset of submaximal treadmill walking were faster in women compared with men.

The temporal dynamics of the oxygen uptake ([Formula: see text]) during moderate exercise has classically been related to physical fitness and a slower [Formula: see text] dynamics was associated with deterioration of physical health. However, methods that better characterize the aerobic system temporal dynamics remain challenging. The purpose of this study was to develop a new method (named mean normalized gain, MNG ) to systematically characterize the [Formula: see text] temporal dynamics. Eight healthy, young adults (28 ± 6 years old, 175 ± 7 cm and 79 ± 13 kg) performed multiple pseudorandom binary sequence cycling protocols on different days and time of the day. The MNG was calculated as the normalized amplitude of the [Formula: see text] signal in frequency-domain. The MNG was validated considering the time constant τ obtained from time-domain analysis as reference. The intra-subject consistency of the MNG was checked by testing the same participant on different days and times of the day. The MNG and τ were strongly negatively correlated ( r = -0.86 and p = 0.005). The MNG measured on different days and periods of the day was similar between conditions. Calculations for the MNG have inherent filtering characteristics enhancing reliability for the evaluation of the aerobic system temporal dynamics. In conclusion, the present study successfully validated the use of the MNG for aerobic system analysis and as a potential complementary tool to assess changes in physical fitness.

Deteriorated aerobic response to moderate exercise might precede the manifestation of clinical symptoms of noncommunicable diseases. The purpose of the current study was to verify that the use of current wearable technologies for analysis of pulmonary oxygen uptake (V̇o 2 ) dynamics during a pseudorandom ternary sequence (PRTS) over-ground walking protocol is a suitable procedure for the investigation of the aerobic response in more realistic settings. A wearable accelerometer located at the hip assessed the magnitude of the input changes delivered to the aerobic system. Eight adults (24 ± 4 yr old, 174 ± 7 cm, and 71.4 ± 7.4 kg) performed two identical PRTS over-ground walking protocols. In addition, they performed on the cycle ergometer two identical pseudorandom binary sequence (PRBS) protocols and one incremental protocol for maximal V̇o 2 determination. In the frequency domain, mean normalized gain amplitude (MNG in %) quantified V̇o 2 dynamics. The MNG during PRTS was correlated (r = -0.80, P = 0.01) with the V̇o 2 time constant (τ) obtained during cycling. The MNG estimated during PRBS was similar to the MNG estimated during PRTS (r = 0.80, P = 0.01). The maximal V̇o 2 correlated with the MNG obtained during the PRBS (r = 0.79, P = 0.01) and PRTS (r = 0.78, P = 0.02) protocols. In conclusion, PRTS over-ground walking protocol can be used to evaluate the aerobic system dynamics by the simultaneous measurement of V̇o 2 and hip acceleration. In addition, the aerobic response dynamics from PRBS and PRTS were correlated to maximal V̇o 2 This study has shown that wearable technologies in combination with assessment of MNG, a novel indicator of system dynamics, open new possibilities to monitor cardiorespiratory health under conditions that better simulate activities of daily living than cardiopulmonary exercise testing performed in a medical environment., (Copyright © 2017 the American Physiological Society.)

The study of oxygen uptake (V̇o 2 ) dynamics during walking exercise transitions adds valuable information regarding fitness. However, direct V̇o 2 measurements are not practical for general population under realistic settings. Devices to measure V̇o 2 are associated with elevated cost, uncomfortable use of a mask, need of trained technicians, and impossibility of long-term data collection. The objective of this study was to predict the V̇o 2 dynamics from heart rate and inputs from the treadmill ergometer by a novel artificial neural network approach. To accomplish this, 10 healthy young participants performed one incremental and three moderate constant work rate treadmill walking exercises. The speed and grade used for the moderate-intensity protocol was related to 80% of the V̇o 2 response at the gas exchange threshold estimated during the incremental exercise. The measured V̇o 2 was used to train an artificial neural network to create an algorithm able to predict the V̇o 2 based on easy-to-obtain inputs. The dynamics of the V̇o 2 response during exercise transition were evaluated by exponential modeling. Within each participant, the predicted V̇o 2 was strongly correlated to the measured V̇o 2 ( = 0.97 ± 0.0) and presented a low bias (~0.2%), enabling the characterization of the V̇o 2 dynamics during treadmill walking exercise. The proposed algorithm could be incorporated into smart devices and fitness equipment, making them suitable for tracking changes in aerobic fitness and physical health beyond the infrequent monitoring of patients during clinical interventions and rehabilitation programs., (Copyright © 2016 the American Physiological Society.)

Background: Type 2 diabetes mellitus (DM) is responsible for a significant reduction in the quality of life due to its negative impact on functional capacity. Cardiopulmonary fitness impairment in DM patients has been associated with limited tissue oxygenation. Phototherapy is widely utilized to treat several disorders due to expected light-tissue interaction. This type of therapy may help to improve muscular oxygenation, thereby increasing aerobic fitness and functional capacity., Methods/design: This study is a randomized, double-blind, placebo-controlled crossover trial approved by the Ethics Committee of the Federal University of São Carlos and registered at ClinicalTrials.gov. Four separate tests will be performed to evaluate the acute effect of phototherapy. All participants will receive both interventions in random order: light-emitting diode therapy (LEDT) and placebo, with a minimum 14-day interval between sessions (washout period). Immediately after the intervention, participants will perform moderate constant workload cycling exercise corresponding to 80 % of the pulmonary oxygen uptake [Formula: see text] during the gas exchange threshold (GET). LEDT will be administered with a multidiode cluster probe (50 GaAIA LEDs, 850 ηm, 75 mW each diode, and 3 J per point) before each exercise session. Pulmonary oxygen uptake, muscle oxygenation, heart rate, and arterial pressure will be measured using a computerized metabolic cart, a near-infrared spectrometer, an electrocardiogram, and a photoplethysmography system, respectively., Discussion: The main objective of this study is to evaluate the acute effects of muscular pre-conditioning using LED phototherapy on pulmonary oxygen uptake, muscle oxygenation, heart rate, and arterial pressure dynamics during dynamic moderate exercise. We hypothesize that phototherapy may be beneficial to optimize aerobic fitness in the DM population. Data will be published after the study is completed., Trial Registration: Registered at ClinicalTrials.gov under trial number NCT01889784 (date of registration 5 June 2013).

We tested the validity of the Hexoskin wearable vest to monitor heart rate (HR), breathing rate (BR), tidal volume (VT), minute ventilation, and hip motion intensity (HMI) in comparison with laboratory standard devices during lying, sitting, standing, and walking. Twenty healthy young volunteers participated in this study. First, participants walked 6 min on a treadmill at speeds of 1, 3, and 4.5 km/h followed by increasing treadmill grades until 80% of their predicted maximal heart rate. Second, lying, sitting, and standing tasks were performed (5 min each) followed by 6 min of treadmill walking at 80% of their ventilatory threshold. Analysis of each individual's mean values under each resting or exercise condition by the 2 measurement systems revealed low coefficient of variation and high intraclass correlation values for HR, BR, and HMI. The Bland-Altman results from HR, BR, and HMI indicated no deviation of the mean value from zero and relatively small variability about the mean. VT and minute ventilation were provided in arbitrary units by the Hexoskin device; however, relative magnitude of change from Hexoskin closely tracked the laboratory standard method. Hexoskin presented low variability, good agreement, and consistency. The Hexoskin wearable vest was a valid and consistent tool to monitor activities typical of daily living such as different body positions (lying, sitting, and standing) and various walking speeds.

Recently, low-level laser (light) therapy (LLLT) has been used to improve muscle performance. This study aimed to evaluate the effectiveness of near-infrared light-emitting diode therapy (LEDT) and its mechanisms of action to improve muscle performance in an elite athlete. The kinetics of oxygen uptake (VO2), blood and urine markers of muscle damage (creatine kinase--CK and alanine), and fatigue (lactate) were analyzed. Additionally, some metabolic parameters were assessed in urine using proton nuclear magnetic resonance spectroscopy ((1)H NMR). A LED cluster with 50 LEDs (λ = 850 nm; 50 mW 15 s; 37.5 J) was applied on legs, arms and trunk muscles of a single runner athlete 5 min before a high-intense constant workload running exercise on treadmill. The athlete received either Placebo-1-LEDT; Placebo-2-LEDT; or Effective-LEDT in a randomized double-blind placebo-controlled trial with washout period of 7 d between each test. LEDT improved the speed of the muscular VO2 adaptation (∼-9 s), decreased O2 deficit (∼-10 L), increased the VO2 from the slow component phase (∼+348 ml min(-1)), and increased the time limit of exercise (∼+589 s). LEDT decreased blood and urine markers of muscle damage and fatigue (CK, alanine and lactate levels). The results suggest that a muscular pre-conditioning regimen using LEDT before intense exercises could modulate metabolic and renal function to achieve better performance.

The hypothesis that cerebrovascular autoregulation was not impaired during head-up tilt (HUT) that followed brief exposures to varying degrees of prior head-down tilt (HDT) was tested in 10 healthy young men and women. Cerebral mean flow velocity (MFV) and cardiovascular responses were measured in transitions to a 60-s period of 75° HUT that followed supine rest (control) or 15 s HDT at -10°, -25°, and -55°. During HDT, heart rate (HR) was reduced for -25° and -55°, and cardiac output was lower at -55° HDT. MFV increased during -10° HDT, but not in the other conditions even though blood pressure at the middle cerebral artery (BPMCA) increased. On the transition to HUT, HR increased only for -55° condition, but stroke volume and cardiac output transiently increased for -25° and -55°. Total peripheral resistance index decreased in proportion to the magnitude of HDT and recovered over the first 20 s of HUT. MFV was significantly less in all HDT conditions compared with the control in the first 5-s period of HUT, but it recovered quickly. An autoregulation correction index derived from MFV recovery relative to BPMCA decline revealed a delay in the first 5 s for prior HDT compared with control but then a rapid increase to briefly exceed control after -55° HDT. This study showed that cerebrovascular autoregulation is modified by but not impaired by brief HDT prior to HUT and that cerebral MFV recovered quickly and more rapidly than arterial blood pressure to protect against cerebral hypoperfusion and potential syncope., (Copyright © 2015 the American Physiological Society.)