Assessment of Maximum Oxygen Uptake in Elite Youth Soccer Players: A Comparative Analysis of Smartwatch Technology, Yoyo Intermittent Recovery Test 2, and Respiratory Gas Analysis.

The maximum oxygen uptake (VO2max) is a critical factor for endurance performance in soccer. Novel wearable technology may allow frequent assessment of V̇O2max during non-fatiguing warm-up runs of soccer players with minimal interference to soccer practice. The aim of this study was to assess the validity of VO2max provided by a consumer grade smartwatch (Garmin Forerunner 245, Garmin, Olathe, USA, Software:13.00) and the YoYo Intermittent Recovery Run 2 (YYIR2) by comparing it with respiratory gas analysis. 24 trained male youth soccer players performed different tests to assess VO2max: i) a treadmill test employing respiratory gas analysis, ii) YYIR2 and iii) during a non-fatiguing warm-up run of 10 min wearing a smartwatch as recommended by the device-manufacturer on 3 different days within 2 weeks. As the device-manufacturer indicates that validity of smartwatch-derived VO2max may differ with an increase in runs, 16 players performed a second run with the smartwatch to test this claim. The main evidence revealed that the smartwatch showed an ICC of 0.37 [95% CI: -0.25; 0.71] a mean absolute percentage error (MAPE) of 5.58% after one run, as well as an ICC of 0.54 [95% CI: -0.3; 8.4] and a MAPE of 1.06% after the second run with the smartwatch. The YYIR2 showed an ICC of 0.17 [95% CI: -5.7; 0.6]; and MAPE of 4.2%. When using the smartwatch for VO2max assessment in a non-fatiguing run as a warm-up, as suggested by the device manufacturer before soccer practice, the MAPE diminishes after two runs. Therefore, for more accurate VO2max assessment with the smartwatch, we recommend to perform at least two runs to reduce the MAPE and enhance the validity of the findings.

Current limits for flowmeter resistance in metabolic carts can negatively affect exercise performance.

PURPOSE: To investigate whether a metabolic cart using a flowmeter in the upper range of accepted resistance to airflow (<1.5 cmH2 O∙L-1 ∙s-1 for flows up to 14 L∙s-1 , American Thoracic Society) negatively impacts exercise performance in healthy individuals. METHODS: 16 recreationally active males (age 25 ± 1 years, height 180 ± 6 cm, weight 73.5 ± 5.8 kg, all mean ± SD) performed two incremental tests on a bicycle ergometer on each of two visits, using a metabolic cart with a flowmeter of either low (Oxycon Pro) or high (Innocor) airflow resistance. Mouth pressures, gas exchange, blood lactate concentration [La- ], perception of breathlessness, respiratory, and leg exertion were assessed throughout the tests. RESULTS: Tests performed with the Innocor were significantly shorter (15.3 ± 3.2 vs. 15.8 ± 3.3 min, p < 0.0001) and showed higher maximal flow resistance (1.3 ± 0.2 vs. 0.3 ± 0.0 cmH2 O∙L-1 ∙s-1 , p < 0.0001). At end-exercise, peak oxygen consumption (-200 ± 220 ml.min-1 , p < 0.0001), minute ventilation (-19.9 ± 10.5 L.min-1 , p < 0.0001), breathing frequency (-5.4 ± 5.2 breaths.min-1 , p < 0.0001), heart rate (-2.1 ± 3.6 bpm, p = 0.002) and [La- ] (-0.7 ± 1.0 mmol.L-1 , p < 0.0001), but not tidal volume (-0.1 ± 0.2 L, p = 0.172) were lower with the Innocor, while the perception of breathlessness was higher (+3.8 ± 5.1 points, p < 0.0001). CONCLUSIONS: Airflow resistance in the upper range of current guidelines can significantly affect exercise performance and respiratory pattern in young, healthy males during incremental exercise. The present results indicate the need to revisit guidelines for devices used in ergospirometry.

The effect of posture on maximal oxygen uptake in active healthy individuals.

PURPOSE: Semi-supine and supine cardiopulmonary exercise testing (CPET) with concurrent cardiac imaging has emerged as a valuable tool for evaluating patients with cardiovascular disease. Yet, it is unclear how posture effects CPET measures. We aimed to discern the effect of posture on maximal oxygen uptake (VO2max) and its determinants using three clinically relevant cycle ergometers. METHODS: In random order, 10 healthy, active males (Age 27 ± 7 years; BMI 23 ± 2 kg m2) underwent a ramp CPET and subsequent constant workload verification test performed at 105% peak ramp power to quantify VO2max on upright, semi-supine and supine cycle ergometers. Doppler echocardiography was conducted at peak exercise to measure stroke volume (SV) which was multiplied by heart rate (HR) to calculate cardiac output (CO). RESULTS: Compared to upright (46.8 ± 11.2 ml/kg/min), VO2max was progressively reduced in semi-supine (43.8 ± 10.6 ml/kg/min) and supine (38.2 ± 9.3 ml/kg/min; upright vs. semi-supine vs. supine; all p ≤ 0.005). Similarly, peak power was highest in upright (325 ± 80 W), followed by semi-supine (298 ± 72 W) and supine (200 ± 51 W; upright vs. semi-supine vs. supine; all p < 0.01). Peak HR decreased progressively from upright to semi-supine to supine (186 ± 11 vs. 176 ± 13 vs. 169 ± 12 bpm; all p < 0.05). Peak SV and CO were lower in supine relative to semi-supine and upright (82 ± 22 vs. 92 ± 26 vs. 91 ± 24 ml and 14 ± 3 vs. 16 ± 4 vs. 17 ± 4 l/min; all p < 0.01), but not different between semi-supine and upright. CONCLUSION: VO2max is progressively reduced in reclined postures. Thus, posture should be considered when comparing VO2max results between different testing modalities.

Utility of the anterior reach Y-BALANCE test as an injury risk screening tool in elite male youth soccer players.

OBJECTIVES: Examine growth and maturation trends in dynamic balance using the anterior reach Y-Balance test, and its utility as an injury risk screening tool. DESIGN: Cross sectional and prospective cohort. SETTING: Elite male youth soccer players. PARTICIPANTS: 346 players grouped as pre, circa or post peak height velocity (PHV). MAIN OUTCOME MEASURES: Pre-season anterior reach absolute and relative Y-Balance test scores and seasonal prospective lower extremity injury monitoring. RESULTS: Absolute reach distances were greatest post-PHV (p < 0.05). Relative to leg length, pre-PHV achieved the highest scores and increased between-limb differences. Significant associations between injury and anterior reach scores were present in pre (OR: 0.94, CI: 0.91-0.98, p < 0.05) and circa-PHV (OR: 1.05, 95% CI: 1.05-1.10, p < 0.05). Increased age (OR: 1.49, 95% CI: 1.04-2.13, p < 0.05) and height (OR: 1.06, 95% CI: 0.99-1.13, p = 0.82) were risk factors post-PHV. No differences in injury occurrence were shown between players with absolute reach difference >4 cm in any group. CONCLUSIONS: Anterior reach scores increased injury risk, but associations were small and inconsistent. The Y-Balance should be used with caution as a screening tool in this cohort.

Use of portable gas analyzers during pediatric field testing.

OBJECTIVE: To compare performance and cardiorespiratory responses in field tests performed by healthy children, with and without the use of a portable gas analyzer (PGA), and to analyze the reproducibility of the tests. METHOD: The study included healthy children aged 6 to 14 years old. The sample was divided into children who underwent field tests (modified shuttle walk test [MSWT], 6-minute walk test [6MWT], and ADL-Glittre for pediatrics [TGlittre-P]) without PGA (GS) and children who carried the equipment K4b2 -COSMED, Rome, Italy (GK). RESULTS: A total of 120 children participated in the study, 31 in the GK (mean age 10.16 ± 1.81 years old) and 89 in GS (mean age 10.1 ± 1.79 years old). The groups did not differ from each other and there was no significant difference in the performance of the 6MWT and MSWT intergroup (P > .05), but the significant alteration in the variables of the cardiorespiratory response was identified. In the TGlittre-P, the GK completed the test in a shorter time than the GS (2.69 ± 0.38 minutes vs 2.91 ± 0.40 minutes) and both presented alterations in most cardiorespiratory variables. The intragroup reproducibility showed concordance in all tests, and there was no concordance between groups (P > .05). CONCLUSION: The use of PGA had a lower time spent on TGlittre-P. In the 6MWT and MSWT, there was no difference in cardiorespiratory performance and response with and without the use of PGA. The three field tests were reproducible, but the same test, with and without the use of PGA, did not show agreement.

Inertial Sensors Embedded in Smartphones as a Tool for Fatigue Assessment Based on Acceleration in Survivors of Breast Cancer.

BACKGROUND: Cancer-related fatigue is a symptom commonly reported in survivors of breast cancer and is the most variable symptom. Besides questionnaires like PIPER to assess cancer-related fatigue, there is a need to objectively measure fatigue. OBJECTIVE: The aim of this study was to assess the physiological dimension of fatigue based on acceleration during a 30-second maximal sit-to-stand test. DESIGN: This was a cross-sectional study. METHODS: Linear acceleration from a smartphone placed on the sternum was recorded in 70 survivors of breast cancer. Fourth-degree polynomial adjustment from the acceleration signal to the vertical and anterior-posterior axis was calculated. The fatigue temporal cut-off point was detected as a change in the curve slope of the first maximum point of acceleration. RESULTS: Women were aged 51.8 (8.9) years with a body mass index of 25.4 (5.1) Kg/m2. They performed 23.6 (6.57) number of repetitions. The mean fatigue cut-off point from the total sample was 10.2 (3.1) seconds. LIMITATIONS: Further research should employ time-prolonged tests to study acceleration behavior beyond 30 seconds as well as include a physiological criterion that justifies the nonlinear saturation of the acceleration-based criterion. CONCLUSIONS: This study assessed fatigue through a low-cost and easy-to-use methodology during a functional and widely used test such as 30-second maximal sit-to-stand. This would allow clinicians to assess fatigue in a short-effort exercise to individualize exercise prescription dose, measure changes during intervention, and track fatigue objectively throughout survivorship.

A new device for patellofemoral instrumented stress-testing provides good reliability and validity.

PURPOSE: To evaluate the reliability of an instrumented patellofemoral (PF) stress-testing-the Porto Patellofemoral Testing Device (PPTD)-and validate the instrumented assessment method comparing to manual physical examination. METHODS: Eight asymptomatic volunteers underwent bilateral PF-instrumented examination with the PPTD and magnetic resonance imaging (MRI) to assess intra-rater reliability of the instrumented assessment methodology. Six patients with unilateral PF instability underwent physical examination and PPTD concomitantly with MRI. Manual examination was performed by two blinded surgeons and compared with PPTD test. Ligament stiffness was calculated and compared between injured and non-injured lower limbs. RESULTS: PPTD showed a pre-determined and reproducible stress-force application with excellent intra-rater agreement (intra-class correlation coefficient 0.83-0.98). The manual exam was imprecise with variable examiner-dependent stress-force application. The PPTD resulted in greater lateral patellar translation (converted in quadrants) than manual exam for patients that have reached maximum translation force. Measurement of patellar position and displacement using PPTD was more accurate and precise than the visual estimation of translated quadrants by manual exam. Ligament stiffness curves showed no relevant changes in patellar displacement after 62 N. CONCLUSION: The PPTD instrumented stress-testing is a valid device to quantify PF position and displacement with high intra-rater reliability, showing more accuracy, more precision and less variability than physical examination. This device provides an accurate and objective measure to quantify the patellar movement which can augment the physical examination procedures and assist clinicians in the management of decision-making and in the assessment of post-treatment outcomes of PF pathological conditions.

Changes in Knee and Trunk Alignment in People With Hip Pain and Healthy Controls When Using a Decline Board During Single-Leg Squat.

CONTEXT: Hip pain is associated with reduced hip muscle strength, range of movement (ROM), and decreased postural stability. Single-leg squat is a reliable and valid method to measure dynamic balance. OBJECTIVE: To evaluate the influence of physical characteristics and use of a decline board on squat performance in a hip pain population. DESIGN: Cross-sectional study setting. Clinical Patients: In total, 33 individuals scheduled for arthroscopic hip surgery were matched with 33 healthy controls. INTERVENTIONS: Hip and ankle ROM, hip strength, and trunk endurance were assessed, along with knee and trunk kinematics during squat on flat and 25° decline surfaces. MAIN OUTCOME MEASURES: Between-group and surface differences in alignment, between-group strength and ROM, and associations between alignment and physical characteristics were assessed and determined using mixed model analysis of variance and Pearson R. RESULTS: The hip pain group had significantly less strength and ROM for all directions except abduction strength and ankle dorsiflexion (P > .02). No differences existed between the 2 groups for trunk (P < .70) or knee displacement (P < .46) during squat on either surface. When the 2 groups were combined (n = 66), decline squat significantly reduced knee medial displacement in both limbs by approximately 1 cm (P < .01). Decline squat reduced trunk lateral movement on 1 side only (P = .03). Reduced knee displacement during decline squat showed fair association with less hip-extension strength (r = -.29), hip-flexion strength (r = -.25), and less dorsiflexion (r = -.24). Strength and range were not associated with trunk displacement. CONCLUSIONS: Decline squat reduced medial knee and lateral trunk displacement regardless of hip pain. Reductions may be greater in those with lesser hip muscle strength and dorsiflexion. Use of a decline board during squat for improving knee and trunk alignment should be considered as a goal of exercise intervention.

Influence of the hydration on autonomic modulation and cardiorespiratory parameters of coronary heart disease patients submitted to a cardiovascular rehabilitation session: crossover clinical trial protocol

Abstract Aims: The influence of fluid replacement, realized during and after the exercise on individuals with coronary artery disease (CAD) remains poorly understood. To investigate the influence of hydration on cardiac autonomic modulation, cardiorespiratory parameters and perceived exertion and discommodity, of coronary heart patients submitted to cardiac rehabilitation (CR) session. Methods: This cross-over clinical trial, will recruit 31 adults with more than 45 years old, participants of a cardiovascular rehabilitation program, with CAD diagnosis. The participants will be submitted to an experimental protocol composed of three phases: I) Maximal stress test; II) Control protocol (CP); and III) Hydration protocol (HP). The CP and HP will consist of 10 min of rest in a supine position, 15 min of warming, 40 min of treadmill exercise, 5 min of cooling down and 60 min of rest in a supine position. In the HP, the participants will be hydrated with mineral water, based on the bodyweight reduction of the CP. The water intake will be divided into eight equal portions, offered during the treadmill exercise and recovery period. On CP and HP will be evaluated linear and nonlinear indices of heart rate variability, the heart rate, systolic blood pressure, diastolic blood pressure, respiratory rate, oxygen partial saturation, perceived exertion and discommodity on specifics moments. Conclusion: The results of this study will allow us to identify if the proposed protocol will be able to positively influence the outcomes and, consequently, if could be implement in the clinical practice.

Heart rate responses of a master athlete during ultra-endurance swimming

Abstract Aim: Swimming races outside swimming pools take place all over the world, but studies focusing on their physiological aspects are scarce. In fact, rules forbid any direct contact with swimmers during sanctioned events. This case report presents heart rate responses of a master athlete during an ultra-endurance open water solo swim and analyzes results based on a prior cardiopulmonary exercise test. Methods: The swimmer performed a cardiopulmonary exercise test on a treadmill, following a ramp protocol, with continuous electrocardiogram recording. The athlete performed a 36 km swimming race with continuous heart rate recording. Description of swimming heart rate accordingly to heart rate training zones and correlation analysis between HR and swim speed was assessed. Results: The athlete swam the 36 km event in 11 hours, 16 minutes and 15 seconds. Most of the swim time was spent in training zone 3 (55%), and only 2% of race time was spent in zone 5. Swimming speed (3.2 ± 0.7 km/h) failed to correlate with HR during the event (r2 = 0.1334, p > 0.05). Conclusion: Although HR did not correlate with swimming speed it successfully indicated exercise intensity during this 36 km event. These results can be used in the preparation and monitoring of other solo long-distance swimmers.

Performance comparison in the Wingate test between standing and seated positions in competitive cyclists

Abstract Aims: The current study aimed to compare the anaerobic power output through the Wingate test in different positions, i.e., standing and seated, and identify the relationship between power-output and body mass. Methods: Eleven male competitive cyclists (age: 30.3 ± 4.7 years; body mass: 73.7 ± 7.7 kg; body fat: 11.3 ± 4.2%) were submitted to two sessions of the Wingate test (WT) in different positions, on different days. Results: The peak power (W), average power (W), relative peak power (W·kg-1), relative average power (W·kg-1), average cadence (rpm), and average velocity (km·h-1) presented significant differences in the standing position compared with the seated position (p < 0.05), 1155 ± 130 vs. 1082 ± 182 (W), 875 ± 96 vs. 818 ± 116 (W), 15.9 ± 1 vs. 15.0 ± 2 (W kg-1), 12.1 ± 1 vs. 11.3 ± 1 (W kg-1), 117.5 ± 7 vs. 109.8 ± 10 (rpm), 37.0 ± 2 vs. 34.6 ± 3 (km·h-1), respectively. However, when controlled the body mass, the differences in variables power output ceased to exist (p > 0.05). The fatigue and peak heart rate (bpm) indices did not present significant differences between the tests (p > 0.05). Conclusions: Sprint performance was improved when the WT was performed in a standing position in competitive cyclists. The study also reports the important relationship between body mass and anaerobic production capacity in the WT, emphasizing that it is desirable an increase in lean body mass and a reduction in fat mass, similar in competitions. We suggest that, for anaerobic assessment in cyclists, the standing position should be used during the WT, to determine the maximum power-output capacity.

Blood glucose threshold determination is stage length dependent

Aim: This study aimed to verify whether different stage length affects the intensity of the Blood Glucose Threshold (BGT), and the agreement between evaluators for BGT determination. Methods: Fourteen subjects attended the laboratory during the first session to perform anthropometric measures and become familiar with procedures. In the following three sessions, subjects performed an incremental test on the ergometer bicycle and in each test a different protocol was performed in randomized order (1, 3- and 5-min stage) to identify BGT. Three different evaluators determined the BGT. Results: Our data show that the BGT is stage length-dependent (1, 3- and 5-min; P<0.0001). The intraclass correlation coefficient showed that there was a strong correlation among evaluators for all protocols (ICC = 0.8 to 1 min; ICC = 0.8 to 3 min; and ICC 0.9 to 5 min). However, one evaluator determined the BGT at a higher intensity than others. The peak load was lower at long stage length. Conclusion: We concluded that stage length influences the BGT intensity determination. The BGT presents a good agreement among evaluators. However, a minimum of two evaluators is needed for BGT determination. The peak load is affected by stage length.(AU)

Diagnostic test accuracy of an automated device as a screening tool for fall risk assessment in community-residing elderly: A STARD compliant study.

We aimed to determine the accuracy and failure of OAK device, an automated screening, for the assessment of fall risk in a prospective cohort of healthy adults aged over 65 years. The algorithm for fall risk assessment of the centers for disease control and prevention (CDC) was used as reference standard. Of the 183 individuals recruited, the CDC algorithm classified 80 as being at moderate/high risk and 103 at low risk of falling. OAK device failure incidence was 4.9% (confidence interval [CI] upper limit 7.7%), below the preset threshold for futility-early termination of the study (i.e., not above 15%). The OAK device showed a sensitivity of 84% and a specificity of 67% (receiver operating characteristic [ROC] area 82%; 95% confidence interval [CI] 76-88%), not reaching the preplanned target sensitivity (not lower than 85%). Diagnostic accuracy was not far from the sensitivity levels similar to those obtained with other fall risk assessment. However, some limitations can be considered.ClinicalTrials.gov identifier: NCT02655796.

Associations between Distance and Loading Symmetry during Return to Sport Hop Testing.

PURPOSE: Hop tests are widely used to quantify recovery from anterior cruciate ligament reconstruction (ACLR) surgery. However, there is evidence that simply measuring hop distance may not be indicative of the quality of movement or representative of potential limitations in hopping mechanics, particularly during landing. The first purpose of the present study was to compare hop distance and loading symmetry between ACLR athletes and healthy uninjured recreational athletes. The second was to determine the association between hop distance and loading symmetry. METHODS: Twenty-five ACLR patients and 30 healthy controls completed the single hop, triple hop, and crossover hop test on each limb while the loadsol®, a single-sensor force insole, collected impact forces (100 Hz). A limb symmetry index (LSI) was calculated for hop distance, peak impact force, loading rate, and impulse from the final landing of each trial. LSI values were compared between groups using Mann-Whitney U tests, and distance and loading LSI values were compared using Spearman rank correlations. RESULTS: ACLR patients had reduced symmetry in hop distance and loading relative to healthy controls for every hop test and outcome measure (P < 0.05), except peak impact force on the single hop. Hop distance symmetry was significantly related to each loading symmetry measure on the crossover hop test (P < 0.01) and to peak impact force and impulse symmetry on the single hop test (P < 0.05) in each group. CONCLUSION: This study demonstrates that ACLR patients both hop further and generate larger forces when hopping on their nonsurgical limb relative to their surgical limb. In addition, hop distance and loading symmetry provide clinicians and researchers with different information and therefore should be considered together when making return to sport decisions.

Exercise Training Improves Heart Rate Recovery after Exercise in Hypertension

Abstract Aim: This study tested the hypothesis that: 1- the exercise training would improve the heart rate recovery (HRR) decline after maximal exercise test in hypertensive patients and; 2- the exercise training would normalize HRR decline when compared to normotensive individuals. Methods: Sixteen hypertensive patients were consecutively allocated into two groups: Exercise-trained (n = 9, 47±2 years) and untrained (n = 7, 42±3 years). An exercise-trained normotensive group (n = 11, 41±2 years) was also studied. Heart rate was evaluated by electrocardiogram. The autonomic function was evaluated based on heart rate changes on the first and the second min of recovery after the maximal exercise test. Exercise training consisted of three 60-minute exercise sessions/week for 4 months. Results: In hypertensive patients, exercise training significantly increased the HRR decline in the first (-19±2 vs. -34±3 bpm, P = 0.001) and second (-33±3 vs. -49±2 bpm, P = 0.006) minutes after the maximal exercise test. In addition, after exercise training, the initial differences in the HRR decline after exercise between hypertensive patients and normotensive individuals were no longer observed (first minute: -34±3 vs. -29±3 bpm, P = 0.52, and second minute: -49±2 vs. -47±4 bpm, P = 0.99). Conclusion: Hypertension causes a delay in HRR after the maximal exercise test yet the exercise training normalizes HRR during the post-exercise period in hypertensive patients.

Aptidão física relacionada à saúde de policiais militares da Paraíba / Health­related physical fitness of military police officers in Paraiba, Brazil

Introdução: Boas relações entre os componentes da aptidão física relacionada à saúde (AFRS) melhoram o desempenho da atividade ocupacional de policiais militares. Objetivo: Verificar a relação entre componentes da AFRS em policiais militares do Batalhão de Operações Policiais Especiais (BOPE) e do Batalhão de Policiamento de Trânsito (BPTRAN). Método: Participaram do estudo 47 policiais com idades entre 26 e 49 anos do sexo masculino fracionados em dois grupos: BOPE (n=25) e o BPTRAN (n=22). Foi realizada uma bateria de testes: medidas antropométricas, teste de sentar-e-alcançar no banco de Wells, teste de abdominal de 1 minuto, teste de flexão dos cotovelos e teste vai-e-vem de 20 metros, para avaliar os componentes morfológico, cardiorrespiratório e neuromuscular da AFRS. Resultados: Ambos os grupos obtiveram de moderada à forte correlação negativa significante em relação à circunferência de cintura (CC), índice de massa corpórea (IMC) e percentual de gordura (PG) com a resistência muscular localizada (RML) (r=-0,589; r=-0,404; r=-0,637) e a força muscular dinâmica (FD) (r=0,592; r=-0,416; r=-0,651) (p<0,05). Contudo, houve correlações positivas e negativas significantes entre o consumo máximo de oxigênio (VO2 máx) e as variáveis CC, IMC, PG e RML (p<0,05), exceto para flexibilidade no BOPE. Conclusão: Existe uma forte correlação entre os componentes morfológico, cardiorrespiratório e neuromuscular, exceto para a flexibilidade em PMs do BOPE. Tal fato permite afirmar que a AFRS é uma variável global

Background: An adequate relationship among health­related physical fitness (HRPF) components improve the professional performance of military police officers (MOPs). Objective: To investigate the correlation among HRPF components for Special Police Operations (BOPE) and Traffic Police (BPTRAN) Battalion MOPs. Method: The sample comprised 47 male MOPs aged 26 to 49 years old divided in two groups BOPE (N=25) and BPTRAN (n=22). The participants were subjected to a test battery­anthropometric measurements, sit­and­ reach test, 1-minute sit­up test, elbow flexion test, and 20­meter shuttle run test­for evaluation of the HRPF morphological, cardiorespiratory and neuromuscular components. Results: Both groups exhibited moderate­to­strong correlation of waste circumference (WC), body mass index (BMI) and body fat percentage (BFP) with localized muscle resistance (LMR) (r=-0.589; r=-0.404; r=-0.637) and dynamic muscle strength (DMS) (r=0.592; r=-0.416; r=-0.651) (p<0.05). Significant positive and negative correlation was found between maximum oxygen consumption and WC, BMI, BFP and LMR (p<0.05) but not with flexibility for BOPE. Conclusion: There was strong correlation between the HRPF morphological, cardiorespiratory and neuromuscular components, except for flexibility among BOPE MPOs. The study findings allow inferring that HRPF is a global variable

Screening Spirometry in Military Personnel Correlates Poorly with Exercise Tolerance and Asthma History.

BACKGROUND: Spirometry is an easy-to-perform test for evaluating pulmonary symptoms but has several limitations to include adequate test performance for valid results. Spirometry is not recommended to screen a general population for evidence of pulmonary disease unless symptoms are present or longitudinal screening is done for potential occupational exposures. METHODS: A single-spirometry examination was performed on 900 active duty Army soldiers, ages 18-35 yr, without documented respiratory disease. Abnormal studies were identified (obstructive, restrictive, mixed, and flow volume loop abnormalities) and compared with reported respiratory symptoms, smoking history, prior diagnosis of asthma, and failure of the Army physical fitness test 2-mile run using generalized linear modeling techniques. RESULTS: The cohort population had spirometry values comparable with published NHANES III reference values. Ninety-eight subjects (10.9%) were identified with abnormal spirometry included 33 obstructive, 44 restrictive, 3 mixed, and 18 isolated flow volume loop abnormalities. Historical features (smoking, exertional dyspnea, cough, asthma, or APFT failure) had no effect on the probability of an abnormal spirometry result (p = 0.56). Although APFT failure probability is strongly affected by exertional dyspnea (p = 0.00) and current smoking (p = 0.01), abnormal spirometry results did not have a statistically significant effect (p = 0.38). DISCUSSION: For potential screening of military personnel with spirometry to detect pulmonary disease, study findings identified a significant percentage with non-specific abnormalities requiring further evaluation. Spirometry may be indicated in those individuals with a history of asthma or active dyspnea symptoms. Spirometry as a screening tool is poorly (and often incorrectly) predictive for respiratory symptoms or decreased exercise tolerance in a military cohort. CONCLUSION: Spirometry should not be used to screen the military force for the presence of respiratory disorders. In those individuals with a history of asthma, in-depth testing should be performed to fully evaluate any non-specific findings identified during spirometry.

Kinematics and metabolic cost of running on an irregular treadmill surface.

The purpose of this study was to investigate the kinematic and metabolic effects of running on an irregular surface. We also examined how altering the frontal plane foot angle (inversion/eversion) at contact using real-time visual feedback would affect these other variables. Sixteen participants completed three running bouts lasting 5-7 minutes each on an irregular surface (IS) treadmill, a traditional smooth surface (SS) treadmill, and on SS while receiving visual feedback of the frontal plane foot angle at contact (SSF) with a goal of matching IS foot angle on SS. Frontal plane foot angle increased 40% from IS to SS (IS: 8.4 ± 4.09°, SS: 11.8 ± 4.52°, P < 0.0001, ES 1.40). Knee flexion angle at contact decreased 33% from IS to SS (IS: 9.2 ± 4.88°, SS: 6.2 ± 5.03°, P < 0.0001, ES 1.30). Rate of oxygen consumption decreased by 10% from IS to SS (IS: 37.9 ± 5.68 ml·kg-1·min-1, SS: 34.1 ± 5.07 ml·kg-1·min-1, P < 0.0001, ES 3.05). PSD of leg accelerations decreased by 38% (IS: 0.17 ± 0.07 g2/Hz, SS: 0.106 ± 0.05 g2/Hz, P < 0.000, ES 1.69). Frontal plane foot angle decreased by 14% from SS to SSF (SS: 11.8 ± 4.52°, SSF: 10.1 ± 4.42°, P = 0.027. ES 0.62) but did not result in significant changes in any other variables. There were no significant differences in shock attenuation between any conditions (IS: -9.8 ± 2.26 dB, SS: -9.5 ± 3.12 dB, SSF: -9.9 ± 2.62 dB, P = 0.671). Running with greater eversion on the irregular surface may be an attempt by runners to reduce the perceived potential of an inversion ankle sprain. As a partial compensation for the decreased foot angle, runners increased knee flexion. This maintained shock attenuation but increased the rate of oxygen consumption. Altering the foot angle at contact using feedback on the SS caused the knee angle at contact to increase, but did not change shock attenuation or metabolic cost.

Evaluation of maximal lactate steady state in middle-aged hypertensive women

Abstract AIM The aim of this study was to investigate the lactate response in physically inactive hypertensive women submitted to the treadmill maximal lactate steady state (MLSS) protocol. METHODS Twenty-two hypertensive women (40 - 64 years) performed a familiarization period of walking on the treadmill following by one incremental test for estimating the initial workload for exercise testing. MLSS protocol was composed by walking in a treadmill during thirty minutes with fixed velocity in 5.5 km/h. Incline was used for determination of the intensity of each volunteer. Blood samples were collected from the ear lobe in the rest period, minute 10th and at the end of the test (minute 30th or at exhaustion time point) for lactate analysis. RESULTS Hypertensive women showed a lower lactate concentration at MLSS (3.25 ± 0.81 mmol/L) as compared with data obtained in the literature (4 mmol/L), approximately 18.8%. Neither inclines nor age affected MLSS parameters in the population. A positive and strong correlation was found between incline and MLSS, as well as incline and lactate level at minute 30th, even when adjusted by age factor. CONCLUSION Physically inactive hypertensive women show a lower MLSS than the average established in the literature but within the range of variations previously reported. Furthermore, a higher MLSS incline correlates positive and directly with higher lactate concentrations for the same aerobic capacity regardless of age.

Evaluación de la actividad física en pacientes con enfermedad pulmonar obstructiva crónica / Tools for physical activity assessment in chronic obstructive pulmonary disease

The prevalence and mortality of chronic obstructive pulmonary disease (COPD) is increasing in Chile, constituting a public health problem. Pulmonary and systemic consequences of COPD affect physical activity, as the disease progresses. There are multiple means for physical activity assessment, from low cost and easily applicable questionnaires to sophisticated laboratory tests. Physical inactivity is a modifiable risk factor for morbidity and mortality in patients with COPD. Physical activity interventions not only contribute to decrease the likelihood of mortality, but also protect from comorbidities, especially cardiovascular ones. It also plays a major role avoiding functional limitations of these subjects. Dyspnea and fatigue render exercise as an unpleasant activity for most patients with COPD. If psychological alterations such as anxiety and depression are summed, these patients drift towards an inactive lifestyle. This article analyzes several tools available to assess physical activity is patients with COPD, useful in clinical practice.