Exercise addiction: a comparison between runners, cyclists, swimmers, and triathletes / Dependência ao exercício: uma comparação entre corredores, ciclistas, nadadores e triatletas / dicción al ejercicio: una comparación entre corredores, ciclistas, nadadores y triatletas

The aim of the present study was to evaluate and compare exercise addiction (EA) between runners, cyclists, swimmers, and triathletes. Took part in this study 39 runners, 32 cyclists, 30 swimmers and 38 triathletes. Exercise Dependence Scale (EDS), and the Exercise Addiction Inventory (EAI) was used to evaluate the EA and classified the participants into: at-risk for EA, nondependent-symptomatic, and nondependent-asymptomatic. Most participants were classified as nondependent symptomatic for EA. The EDS total score was significantly lower in the swimmers compared to the cyclists and triathletes and the EAI total score was significantly higher for cyclists compared to runners. Therefore, in both instruments, the majority of participants was nondependent symptomatic for EA (AU).

O objetivo do presente estudo foi avaliar e comparar a dependência ao exercício (DE) entre corredores, ciclistas, nadadores e triatletas. Participaram do estudo 39 corredores, 32 ciclistas, 30 nadadores e 38 triatletas. As escalas Exercise Dependence Scale (EDS) e Exercise Addiction Inventory (EAI) foram usadas para a avaliação da DE e classificaram os participantes em três categorias: em risco de DE, não dependente sintomático e não dependente assintomático. A maioria dos participantes foram classificadas como não dependentes sintomáticos para DE. O escore da EDS foi significativamente menor nos nadadores comparado aos ciclistas e triatletas e o escore total da EAI foi significantemente maior nos ciclistas comparado aos corredores. Portanto, em ambos os instrumentos, a maioria dos participantes foi não dependente sintomático para DE (AU).

El objetivo del presente estudio fue evaluar y comparar la adicción al ejercicio (AE) entre corredores, ciclistas, nadadores y triatletas. Participaron de este estudio 39 corredores, 32 ciclistas, 30 nadadores y 38 triatletas. La Escala de Dependencia al Ejercicio (EDS) y el Inventario de Adicción al Ejercicio (EAI) fueron utilizados para evaluar la AE y clasificaron a los participantes en tres categorías: en riesgo de AE, no dependiente-sintomático y no dependiente-asintomático. La mayoría de los participantes se clasificaron como no dependiente-sintomático para AE. La puntuación EDS fue significativamente menor en nadadores en comparación con ciclistas y triatletas y la puntuación EAI total fue significativamente mayor en ciclistas en comparación con corredores. Por lo tanto, en ambos instrumentos, la mayoría de los participantes eran sintomáticos no dependientes para AE

Effects of photobiomodulation and deep water running in patients with chronic non-specific low back pain: a randomized controlled trial.

Photobiomodulation therapy (PBM) is often used to treat musculoskeletal disorders such as chronic non-specific low back pain (NSCLBP) as it can have positive effects on biomarkers-creatine kinase (CK) and serum cortisol levels-related to stress caused by physical exercise, such as deep water running (DWR) or by pain. The aim of this study was to evaluate the effects of the combination of PBM and aquatic exercise (DWR) on the intensity of pain, disability, 6-min walk test adapted (6WTA), and on cortisol and creatine kinase (CK) levels in a population with NSCLBP. The participants were allocated into three groups: TGPBM (Photobiomodulation and Training Group), TGPLA (Placebo Photobiomodulation and Training Group), and the GPBM (Photobiomodulation Group). Information regarding anthropometric data, blood pressure, and heart rate were collected, and the questionnaires were applied: IPAQ-Short Form, Oswestry Disability Index, and the Visual Analog Scale for Pain. The submaximal exercise test (6WTA) was performed. Blood was collected for analysis of cortisol and CK levels. The training sessions were performed twice a week, for 4 weeks. In the intragroup comparisons, there were statistically significant changes in the TGPBM and GPBM groups in the outcomes pain intensity, disability (reductions in both groups), and in cortisol (increased in the TGPBM and reduced in the GPBM); in the TGPLA group, there was a statistically significant reduction only in the outcome of pain intensity. In the intergroup comparison, in the comparison between TGPBM and TGPLA, there was a statistically significant difference in the level of cortisol, as well as in the comparison between TGPBM and GPBM, in which there was a statistically significant difference for this same outcome (cortisol) and for the 6WTA outcome. The effects of the combination of PBM and aquatic exercise have positive effects on reducing pain intensity, disability, and cortisol levels, but its effects on other variables (6WTA and CK) are too small to be considered significant. Trial registration number: NCT03465228-April 3, 2019; retrospectively registered (ClinicalTrials.gov).

Individually guided training prescription by heart rate variability and self-reported measure of stress tolerance in recreational runners: Effects on endurance performance.

The aim of this study was to determine the effect of endurance training individually guided by objective (Heart Rate Variability-HRV) or self-report measure of stress (DALDA-questionnaire) in comparison to predefined endurance training prescription for improving endurance performance in recreational runners. After a 2-week preliminary baseline period to establish resting HRV and self-reported measure of stress, thirty-six male recreational runners were randomly assigned to HRV-guided (GHRV; n = 12), DALDA-guided (GD; n = 12) or predefined training (GT; n = 12) prescription groups. Before and after 5-weeks of endurance training, participants performed a track field peak velocity (Vpeak_TF), time limit (Tlim) at 100% of Vpeak_TF and 5 km time-trial (5 km TT) tests. GD lead to higher improvements in Vpeak_TF (8.4 ± 1.8%; ES = 1.41) and 5 km TT (-12.8 ± 4.2%; ES = -1.97), than GHRV (6.6 ± 1.5% and -8.3 ± 2.8%; ES = -1.20; 1.24) and GT (4.9 ± 1.5% and -6.0 ± 3.3%; ES = -0.82; 0.68), respectively, with no differences for Tlim. Self-report measures of stress may be used to individualize endurance training prescription on a daily basis leading to better performance enhancement, which may be used with HRV for a holistic understanding of daily training-induce adaptations.

Effect of photobiomodulation on maximal lactate production rate on swimmers: a randomized, crossover, double-blind and placebo-controlled study

Abstract Aim: This study aimed to verify the acute effect of photobiomodulation (PBM) on maximal lactate production rate (VLamax) in front crawl swimmers. Methods: Fifteen male swimmers (20.9 ± 2.4-year-old) participated in this study. Three sets of front crawls were performed at distances of 100-, 200- and 400-m under three experimental conditions: PBM (420 J), placebo (PLA) and control (C) in this randomized, crossover, double-blind and placebo-controlled study. PBM or PLA were applied or simulated before performance tests. One-way Anova for repeated measurements were used for statistical analyses. Results: The results showed that the prior PBM application did not affect VLamax in front crawl swimmers: VLamax 100-m (PBM = 0.20 ± 0.05 mmol·L-1·s-1; PLA = 0.20 ± 0.04 mmol·L-1·s-1 and C = 0.21 ± 0.04; mmol·L-1·s-1); 200-m (PBM = 0.09 ± 0.03 mmol·L-1·s-1; PLA = 0.08 ± 0.02 mmol·L-1·s-1 and C = 0.08 ± 0.02 mmol·L-1·s-1) and 400-m (PBM = 0.04 ± 0.01 mmol·L-1·s-1; PLA = 0.04 ± 0.01 mmol·L-1·s-1 and C = 0.03 ± 0.01 mmol·L-1·s-1). Nor effect swim time (ST) performance: ST 100 m (PBM = 65.5 ± 6.3 s; PLA = 65.2 ± 5.6 s; C = 66.0 ± 5.9 s); ST 200 m (PBM = 148.5 ± 17.9 s; PLA = 149.4 ± 16.4 s; C = 150.1 ± 17.9 s); ST 400 m (PBM = 327.7 ± 38.2 s; PLA = 321.6 ± 47.7 s; C = 329.5 ± 41.2 s). Conclusions: PBM application prior front crawl swimming tests did not significantly modify the VLamax on swimmers covering distances of 100-, 200- and 400-m.

Are rating of perceived exertion and heart rate methods useful to monitor the internal training load in functional training?

Abstract Aim: The study aimed to quantify and characterize the Training Load (TL) in a Functional Training (FT) model using Heart Rate (HR) and Session Rating of Perceived Exertion (sRPE) methods, and to verify whether these methods could be valid to monitor the TL during a FT program. Methods: The study design consisted of two phases: phase 1 - composed of a single training session of FT (FTSESSION), in which HR, sRPE, and pre- and post-exercise lactate [La] levels were assessed; phase 2 - composed of a FT program (FTPROGRAM) with eight weeks of duration and two sessions per week. The HR and SRPE were utilized to monitor all training sessions, and the results between sessions 1 vs. 8, 8 vs. 9, and 9 vs. 16 were compared. Results: On phase 1, HR distribution demonstrated that the participants spent about 75% of the total training time above 80% HRmax. Post-exercise [La] values were significantly higher (p < 0.05) than pre-exercise. The mean sRPE score was 8.5 ± 1.2. In phase 2, HR distribution was different between sessions 1-8 and 8-9 (p < 0.05). A strong correlation (r = 0.790) between the internal training load (ITL) and Training impulse (TRIMP) was observed. Conclusion: Our data demonstrated that the FTSESSION can be characterized as a high-intensity exercise, based on the pattern of HR responses and sRPE, and was reinforced by the [Lapeak]. Also, the TL monitoring methods (sRPE and TRIMP) proved to be valid for monitoring FT programs.

Reliability of Peak Running Velocity Obtained on the Track Field in Runners of Different Performance Levels.

The aim of this study was to verify the reliability of peak running velocity obtained on the track field (Vpeak_TF) in runners of different performance levels. 39 male endurance runners were divided into two groups: trained runners (TR; n = 22; 10-km time running performance of 35.2 ± 1.7 min), and recreational runners (RR; n = 17; 10-km time running performance of 51.3 ± 4.8 min). They performed three maximal incremental running tests on the official track field (400 m), with an interval of 1 week between trials to determine the reliability of Vpeak_T. The Vpeak_TF showed high reliability, presenting an intraclass correlation coefficient and coefficient of variation of 0.97 and 1.28%, and 0.90 and 1.24% for TR and RR, respectively. Both TR and RR showed lowest bias and limits of agreement between test and retest (Vpeak_TF1 and Vpeak_TF2). In addition, there was no statistical test-retest difference for Vpeak_TF. In addition, the HR and RPE submaximal values were reliable for both TR and RR. Therefore, the Vpeak_TF showed high reliability in both TR and RR. These findings reinforce that the protocol for determining Vpeak_TF, using increments of 1 km h-1 every 3 min is reliable regardless of the performance level of the runners.

Peak Running Velocity or Critical Speed Under Field Conditions: Which Best Predicts 5-km Running Performance in Recreational Runners?

This study aimed to examine which variable, between the peak running velocity determined on the track field (V peak_TF) and critical speed (CS), is the best predictor of the 5-km running performance in recreational runners. Twenty-five males performed three tests to determine the V peak_TF, CS, and 5-km running performance on the track field, with a minimal interval of 48 h between each test. The V peak _TF protocol started with a velocity of 8 km⋅h-1, followed by an increase of 1 km⋅h-1 every 3 min until volitional exhaustion, which was controlled by sound signals, with cones at every 25 m indicating when the participants were required to pass the cone's position to maintain the required velocity. The participants performed three time trials (TTs) (1: 2,600 m; 2: 1,800 m; and 3: 1,000 m) on the same day, with a 30-min rest period to determine the CS through the combinations of three (CS1,2,3) and two TTs (CS1,2, CS1,3, and CS2,3). The 5-km running performance time was recorded to determine the test duration, and the mean velocity (MV) was calculated. There was a significant difference observed between the V peak_TF and the MV 5-km running performance. However, no differences were found between the CS values and the MV 5-km running performance. A correlation was observed between the V peak_TF (R = -0.90), CS1,2,3 (R = -0.95), CS1,3 (R = -0.95), and the 5-km running performance time. Linear regression indicated that the V peak_TF (R 2 = 0.82), CS1,2,3 (R 2 = 0.90), and CS1,3 (R 2 = 0.90) significantly predicted the 5-km running performance time. The CS results showed a higher predictive power for the 5-km running performance, slightly better than the V peak_TF. Also, CS1,2,3 and the CS1,3 presented the highest predictive power for the 5-km running performance of recreational runners.

Comparison of performance-related responses to an endurance running training between untrained men and women / Comparación de respuestas relacionadas con el rendimiento a un entrenamiento de carrera de resistencia entre hombres y mujeres no entrenados

INTRODUCTION: The adherence on endurance running events is increasing exponentially around the World in both previously untrained men and women, thus the incorporation of more appropriate and individualized training approaches are required. It is not known if male and female untrained runners differ in the responses to endurance running training on performance-related variables. OBJECTIVE: We aimed to compare performance-related responses to an endurance running training program between untrained men and women. MATERIAL AND METHOD: Sixteen participants (8 men and 8 women) were paired in the baseline by age, body mass index, and percentage in which time to complete 5 km (t5km) represented from the average of best 50 runners t5km in the greatest regional race for each gender. They completed an 11-week training protocol alternating high-intensity interval training and moderate-intensity continuous running, three times per week, in a running track. In the week 1 and 11 of the protocol (baseline and post-training weeks), peak running velocity at treadmill (Vpeak), time limit (tlim) at 100% Vpeak, t5km, and the index rMSSD of heart rate variability (HRV ) were measured for cardiac autonomic function. Baseline gender-differences were accounted in the analysis. RESULTS: Male and female significantly improved Vpeak (9.4 ± 1.7% and 7.2 ± 1.7%, respectively) and t5km (-13.0 ± 1.8% for both), and no gender-related differences for the adaptations in these two variables were observed. The tlim at 100% Vpeak and rMSSD did not change across the training period in both groups. Percentage of change for men was "moderately" higher than for women for rMSSD (33.4 ± 40.7% vs. 13.9 ± 21.4%), although statistically non-significant. CONCLUSION: Men and women responses to training were similar with regards to their running performance and cardiac autonomic function. With regards to practical application, Vpeak and its tlim can be applied in exercise settings for the prescription of moderate- to high-intensity running training with similar benefits regardless of the biological gender

INTRODUCCIÓN: La adherencia a los eventos de carreras de resistencia está aumentando exponencialmente en el mundo entre hombres y mujeres no entrenados, y por eso es necesaria la incorporación de un entrenamiento individualizado y apropiado. No se sabe si los hombres y mujeres desentrenados en carrera difieren en las respuestas al entrenamiento de carrera de resistencia en relación a las variables relacionadas con el rendimiento. OBJETIVO: Nuestro objetivo fue comparar las respuestas del rendimiento durante un programa de entrenamiento de carrera de resistencia entre hombres y mujeres no entrenados. MATERIAL Y MÉTODO: Dieciséis participantes (8 hombres y 8 mujeres) fueron emparejados en la línea de base por edad, índice de masa corporal y porcentaje del tiempo para completar los 5 km (t5km) representados por el promedio de los t5km de los 50 mejores corredores obtenidos en las mejores carreras regionales (para cada género). Los participantes completaron un protocolo de entrenamiento de 11 semanas alternando entrenamiento de intervalos de alta intensidad con entrenamiento continuo de intensidad moderada, tres veces por semana, en una pista de atletismo. En las semanas 1 y 11 del protocolo (línea de base y semana posterior al entrenamiento), se midieron la velocidad máxima de carrera en la cinta (Vpeak), el tiempo límite (tlim) en Vpeak, t5km y el índice rMSSD de la variabilidad de la frecuencia cardíaca (VFC) para la función cardíaca autónoma. En los análisis se consideraron las diferencias entre géneros en la línea de base. RESULTADOS: Hombres y mujeres mejoraron significativamente la Vpeak (9,4 ± 1,7% y 7,2 ± 1,7%, respectivamente) y el t5km (-13,0 ± 1,8% para ambos), y se observaron diferencias relacionadas con el género para las adaptaciones en estas dos variables. El tlim en Vpeak y el rMSSD no han cambiado durante el período de entrenamiento en ambos grupos. El porcentaje de cambio en los hombres fue moderadamente superior al de las mujeres para la rMSSD (33,4 ± 40,7% vs. 13,9 ± 21,4%), aunque no fue significantemente diferente. CONCLUSIÓN: Las respuestas de hombres y mujeres al entrenamiento fueron similares considerando el rendimiento de carrera y la función cardíaca autónoma. En relación con la aplicación práctica, Vpeak y su respectivo tlim se pueden aplicar en programaciones de ejercicio para prescribir intensidades de entrenamiento de carrera con intensidades moderadas a altas y con beneficios similares, independientemente del género

Effects of a backward running training on backward peak velocity running, V̇O2max, vVO2max and 3 km forward running performance in male adults: a pilot study

Abstract Aims: The study aimed to evaluate the effects of a backward running (BR) training program prescribed by the peak backward running velocity (Vpeak_BR) on physiological variables and a 3 km forward running (FR) performance. Methods: Eight untrained running male adults in running took place in the study. All the participants underwent five weeks of BR training prescribed based on Vpeak_BR. They performed a maximal incremental test on the treadmill to determine the maximal oxygen uptake (V̇O2max) and the velocity associated with V̇O2max (vV̇O2max). The participants were also tested on the track field to determine the Vpeak_BR and undertook a 3 km FR performance. All initial assessments were also performed after the training period. Results: The results showed statistically significant improvements in 3 km FR performance (14.2 ± 1.2 min vs. 13.5 ± 1.0 min) and Vpeak_BR (8.0 ± 0.8 km·h−1 vs. 8.5 ± 0.5 km·h−1) after the training period. Conclusion: BR training effectively improved 3 km FR performance and Vpeak_BR, demonstrating that Vpeak_BR determined according to the protocol proposed in this study can be used for the prescription of BR training. Further, BR training represents an effective training method that can be inserted into an FR running training program.

Does Previous Application of Photobiomodulation Using Light-Emitting Diodes at Different Energy Doses Modify the Peak Running Velocity and Physiological Parameters? A Randomized, Crossover, Double-Blind, and Placebo-Controlled Study.

Objective: This study aimed to verify the acute effects of photobiomodulation (PBM) using different doses of LED on peak running velocity (Vpeak) and physiological parameters. Materials and methods: The study had a randomized, crossover, double-blind, and placebo-controlled format, in which 15 physically active males were submitted, besides the control (CON), to four conditions performed 5 min before the maximal incremental treadmill tests for the determination of Vpeak: placebo (PLA) and three conditions of PBM application at different doses: PBM applied with 30 J per area (PBM1), PBM applied with 120 J per area (PBM2), and PBM applied with 180 J per area (PBM3). The LED was applied using an equipment with 56 diodes of red light (660 nm; 50 mW/cm2 and 1.5 J/cm2 each diode) and 48 diodes of infrared light (850 nm; 150 mW/cm2 and 4.5 J/cm2 each diode). The PBM was applied in two regions of the quadriceps muscle, two regions of the femoral biceps muscle, and one region of the gastrocnemius muscle in both legs. Results: There was no difference among the outcomes from PBM irradiations and PLA condition for the variables, Vpeak (CON = 13.4 ± 1.6; PLA = 13.4 ± 1.6; PBM1 = 13.5 ± 1.7; PBM2 = 13.4 ± 1.6; PBM3 = 13.4 ± 1.7 km/h), similar to other variables associated with aerobic running performance analyzed during the maximal incremental treadmill tests for Vpeak determination: lactate peak, heart rate, and rating of perceived exertion. Conclusions: We concluded that the application of different doses of PBM using LEDs did not modify Vpeak and physiological and perceptual parameters.

Changes in mood state and recovery-stress perception after an HRV-guided running program in untrained women / Cambios en el estado de ánimo y la percepción del estrés de recuperación después de un programa de carrera guiado por HRV en mujeres sin entrenamiento / Alterações no estado de humor e na percepção do estresse na recuperação após um programa de corrida guiada pela VFC em mulheres não treinadas

To determine the effects of HRV-guided running training on mood state and recovery-stress factors in untrained women. Thirty untrained women were randomized into two groups. The CG performed a pre-defined training program while the HRVG completed their running training regarding the intensity distribution according to the parasympathetic activity. The questionnaires of perception of recovery-stress and mood state were answered pre and post-training. The CG reported reduced emotional stress (-0.8 ± 1.3), conflicts/pressure (-0.8 ± 0.8), and increased sleep quality (0.9 ± 1.1), personal acceptance (0.9 ± 1.6), self-regulation (0.8 ± 1.3), specific recovery mean (0.6 ± 0.9), and total recovery mean (0.4 ± 0.7). The HRVG reported decreased general stress (-0.5 ± 0.8), emotional stress (-0.7 ± 1.2), social stress (-0.8 ± 1.0), lack of energy (-0.8 ± 0.8), general stress mean (-0.5 ± 0.8), and increased self-regulation (0.7 ± 1.1). This group also decreased tension (-2.8 ± 3.7), depression (-2.7 ± 4.2), anger (-2.8 ± 4.4) and fatigue (-2.7 ± 3.7) and TMD (-10.7 ± 14.2). HRVG reduced negative scales of mood state and stress factors that were not observed in the controls

Determinar los efectos del entrenamiento de carrera guiado por la VFC sobre el estado de ánimo y los factores de recuperación-estrés en mujeres no entrenadas. Treinta mujeres sin entrenamiento fueron separadas en dos grupos al azar. El GC realizó un programa de entrenamiento predefinido, mientras que el GVFC completó su entrenamiento de carrera con respecto a la distribución de intensidad según la actividad parasimpática. Los cuestionarios de percepción de recuperación-estrés y estado de ánimo se respondieron antes y después del entrenamiento. El GC presentó una reducción del estrés emocional (-0,8 ± 1,3), conflictos / presión (-0,8 ± 0,8) y una mayor calidad del sueño (0,9 ± 1,1), aceptación personal (0,9 ± 1,6), autorregulación (0,8 ± 1,3), media de recuperación específica (0,6 ± 0,9) y media de recuperación total (0,4 ± 0,7). El GVFC presentó una disminución del estrés general (-0,5 ± 0,8), estrés emocional (-0,7 ± 1,2), estrés social (-0,8±1,0), falta de energía (-0,8 ± 0,8), media de estrés general (-0,5 ± 0,8), y aumento de la autorregulación (0,7 ± 1,1). Hubo disminución de la tensión (-2,8 ± 3,7), depresión (-2,7 ± 4,2), ira (-2,8 ± 4,4), fatiga (-2,7 ± 3,7) y TAT (-10,7 ± 14,2) en el GVFC. El GVFC mejoró el estado de ánimo y factores de estrés que no se observaron en los controles

Determinar os efeitos do treinamento de corrida guiado pela VFC sobre o estado de humor e fatores de recuperação-estresse em mulheres não-treinadas. Trinta mulheres não-treinadas foram randomizadas em dois grupos. O GC realizou um programa de treinamento pré-definido, enquanto que o GVFC completou seu treinamento de corrida no que diz respeito à distribuição das intensidade segundo a atividade parassimpática. Os questionários de percepção da recuperação-estresse e estado de humor foram respondidos antes e após o programa de treinamento. O GC apresentou redução do estresse emocional (-0,8 ± 1,3), conflitos/pressão (-0,8 ± 0,8) e uma maior qualidade do sono (0,9 ± 1,1), aceitação pessoal (0,9 ± 1,6), auto-regulação (0,8 ± 1,3), média da recuperação específica (0,6 ± 0,9) e média da recuperação total (0,4 ± 0,7). O GVFC apresentou diminuição do estresse geral (-0,5 ± 0,8), estresse emocional (-0,7 ± 1,2), estresse social (-0,8 ± 1,0), falta de energia (-0,8 ± 0,8), média do estresse geral (-0,5 ± 0,8), e aumento da auto-regulação (0,7 ± 1,1). Houve diminuição da tensão (-2,8 ± 3,7), depressão (-2,7 ± 4,2), raiva (-2,8 ± 4,4), fadiga (-2,7 ± 3,7) e THT (-10,7 ± 14,2) no GVFC. O GVFC reduziu as escalas negativas de humor e fatores de estresse que não foram observados nos controles

Peak running velocity predicts 5-km running performance in untrained men and women / La velocidad máxima predice el rendimiento en la prueba de 5 km en hombres y mujeres no entrenados

OBJECTIVE: The aim of the present study was to examine the relationship between 5-km running performance and peak running velocity (Vpeak) in untrained men and women and propose sex-specific equations for performance prediction based on Vpeak. METHODS: Fifty young and untrained participants (20 female and 30 male) aged between 20 and 35 years participated in this study. Firstly, they performed a continuous incremental test on treadmill to determine Vpeak; the second test was a 5-km running performance performed in 400 m outdoor track. Vpeak test started with a velocity of 8 km/h-1 and increased by 1 km/h-1 between each successive 3-minute stage until participants reached volitional exhaustion. The 5-km time trial running performance for each participant were recorded and registered by the evaluator to determine the test duration (t5km). The comparisons between female and male were performed using Student ́s t test for independent samples; the relationship between Vpeak and 5km running performance was examined using Pearson correlation coefficient (r), adjusted coefficient of determination (R2) and standard error of estimate (SEE). Simple linear regression analyses were used to generate predictive equations for t5km from Vpeak. RESULTS: The Vpeak and 5-km performance (t5km and MV5km) were significant higher for the male group compared to the female group (P < 0.001). In addition, both female and male presented high correlations values for the association between Vpeak and t5km. CONCLUSION: Vpeak is a good predictor of 5-km endurance running performance in untrained men and women. In practical application, Vpeak could be used to prescribe and control running training in beginners in running practice

OBJETIVO: El objetivo del presente estudio fue examinar la relación entre el rendimiento en la carrera de 5 km y la velocidad máxima (Vpeak) en hombres y mujeres no entrenados y proponer ecuaciones específicas de acuerdo con el sexo para la predicción del rendimiento basada en la Vpeak. MÉTODOS: Cincuenta participantes jóvenes y no entrenados (20 mujeres y 30 hombres) con edades comprendidas entre 20 y 35 años participaron en este estudio. Primero, realizaron una prueba incremental continua en la cinta rodante para determinar la Vpeak; la segunda prueba fue una prueba de 5 km realizada en una pista de 400 m al aire libre. La prueba para determinar la Vpeak comenzó con una velocidad de 8 km∙h-1 y aumentó en 1 km∙h-1 entre cada etapa sucesiva de 3 minutos hasta que los participantes alcanzaron el agotamiento volitivo. El rendimiento de cada participante fue registrado por el evaluador para determinar la duración de la prueba (t5km). Las comparaciones entre mujeres y hombres se realizaron utilizando el Student's t test para muestras independientes; la relación entre Vpeak y el rendimiento en la prueba de 5 km se examinó utilizando el coeficiente de correlación de Pearson (r), el coeficiente de determinación ajustado (R2) y el error estándar de estimación (SEE). Se utiliza el análisis de regresión lineal simple para generar ecuaciones predictivas para t5km desde la Vpeak. RESULTADOS: Vpeak y 5-km (t5km y MV5km) fueron significativamente mayores para el grupo masculino en comparación con el grupo femenino (P < 0.001). Además, tanto hombres como mujeres presentaron altos valores de correlaciones para la asociación entre Vpeak y t5km. CONCLUSIÓN: Vpeak es una buena predictora del rendimiento em la prueba de 5-km en hombres y mujeres no entrenados. En la aplicación práctica, Vpeak puede utilizarse para prescribir y controlar el entrenamiento de carrera en principiantes en la práctica de correr

Effects of Endurance Running Training Associated With Photobiomodulation on 5-Km Performance and Muscle Soreness: A Randomized Placebo-Controlled Trial.

This study aimed to investigate the influence of endurance running training associated with PBM on endurance performance variables and muscle soreness in untrained men. Thirty untrained men were distributed randomly into a placebo (PLA) group and photobiomodulation group (PBMG) and they performed 8 weeks of running training. The PBMG had the PBM performed before all training sessions. The PBM was applied using LED equipment with 56 diodes of red light (660 nm) and 48 diodes of infrared light (850 nm). The application was performed in 5 points per leg, with a dose of 60 J at each point and a total energy delivered per leg of 300 J. Peak running velocity, time limit tests and 5-km performance were assessed pre and post-training; muscle soreness was evaluated before all training sessions. The Vpeak increased and 5-km running time (t5-km) decreased (P < 0.001) in both groups. In addition, the magnitude based-inference analysis showed a possibly positive effect on Vpeak and t5-km and for PBMG compared to PLA group. Furthermore, there was a moderate ES of 0.82 on attenuation in muscle soreness in the third week of endurance running training. Therefore, although the magnitude-based inference analysis demonstrated a possibly positive effect on Vpeak and t5-km and for PBMG compared to PLA group and a moderate ES on attenuation in muscle soreness in the last weeks of endurance running training, no significant difference were found between PBMG and PLA interventions.

Effects of chronic beetroot juice supplementation on maximum oxygen uptake, velocity associated with maximum oxygen uptake, and peak velocity in recreational runners: a double-blinded, randomized and crossover study.

PURPOSE: This study investigated the effects of chronic 3-day beetroot juice (BRJ) supplementation on maximum oxygen uptake (VO2max), velocity associated with VO2max(vVO2max), and peak velocity (Vpeak) in recreational runners. METHODS: Thirteen male recreational runners (age 28.2 ± 3.0 years, height 176.8 ± 0.1 cm, body mass 74.4 ± 9.5 kg) performed four tests on a treadmill in a randomized, double-blind, crossover design: two maximum incremental tests to determine VO2max and vVO2max, and two tests to determine Vpeak. Trials were performed following 3 days of supplementation of NO3--rich BRJ in natura (8.4 mmol NO3- day- 1) or BRJ NO3--depleted placebo (0.01 mmol NO3- day- 1), with the last dose being ingested 2 h before each test. During the tests, maximum heart rate (HRmax), maximal rating of perceived exertion (RPEmax), pre- and post-test glucose concentrations (Glucpre, Glucpost), and peak blood lactate concentration were determined. RESULTS: VO2max was higher following BRJ vs PLA (46.6 ± 6.4 vs 45.1 ± 5.8 mL kg- 1 min- 1; P = 0.022), as well as vVO2max (14.5 ± 0.8 vs 13.9 ± 1.0 km h- 1P = 0.024) and Vpeak (15.5 ± 1.1 vs 15.2 ± 1.2 km h- 1P = 0.038), with no differences in the other variables. CONCLUSION: Consumption of NO3--rich BRJ in natura (8.4 mmol NO3- day- 1) once per day for 3 days improved VO2max, vVO2max and Vpeak in recreational runners without changing the other analyzed variables.

Effect of beetroot juice supplementation on 10-km performance in recreational runners.

The purpose of this study was to investigate the effects of chronic beetroot juice (BRJ) supplementation on 10-km running performance in recreational runners. In a double-blind, placebo-controlled, crossover-designed study, 14 male recreational runners (age, 27.8 ± 3.4 years) performed three 10-km running tests, at baseline and under the conditions of BRJ supplementation and placebo (PLA). Supplementation was administered for 3 days, and on the days of the assessments, the ingestion occurred 2 h before the test and consisted of a dose of 420 mL of BRJ in natura (8.4 mmol inorganic nitrate (NO3-)·day-1) or PLA with depleted NO3- (0.01 mmol NO3-·day-1). The mean velocity (MV) was calculated, and the following variables were determined: maximal heart rate, maximal rating of perceived exertion, blood glucose concentration (analyzed before and after the test), and lactate peak. There was no main effect between conditions regarding 10-km running time performance (BRJ: 50.1 ± 5.3 min; PLA: 51.0 ± 5.1 min; P = 0.391) and total MV (BRJ: 12.1 ± 1.3 km·h-1; PLA: 11.9 ± 1.2 km·h-1; P = 0.321) or in the other analyzed variables. The time to complete the first half of the test (5 km) was statistically lower in the BRJ group than in the PLA group (P = 0.027). In conclusion, chronic supplementation with BRJ increased MV in the first half of the test and improved the final test times of 10 of the 14 runners, although we did not find a statistically significant difference in the performance of the 10-km run.

LED session prior incremental step test enhance VO2max in running.

This study aimed to investigate the effect of prior LED sessions on the responses of cardiorespiratory parameters during the running incremental step test. Twenty-six healthy, physically active, young men, aged between 20 and 30 years, took part in this study. Participants performed two incremental load tests after placebo (PLA) and light-emitting diode application (LED), and had their gas exchange, heart rate (HR), blood lactate, and rating of perceived exertion (RPE) monitored during all tests. The PLA and LED conditions were compared using the dependent Student t test with significance set at 5%. The T test showed higher maximum oxygen uptake (VO2max) (PLA = 47.2 ± 5.7; LED = 48.0 ± 5.4 ml kg-1 min-1, trivial effect size), peak velocity (Vpeak) (PLA = 13.4 ± 1.2; LED = 13.6 ± 1.2 km h-1, trivial effect size), and lower maximum HR (PLA = 195.3 ± 3.4; LED = 193.3 ± 3.9 b min-1, moderate effect size) for LED compared to PLA conditions. Furthermore, submaximal values of HR and RPE were lower, and submaximal VO2 values were higher when LED sessions prior to the incremental step test were applied. A positive response of the previous LED application in the blood lactate disappearance was also demonstrated, especially 13 and 15 min after the test. It is concluded that LED sessions prior to exercise modify cardiorespiratory response by affecting running tolerance during the incremental step test, metabolite clearance, and RPE. Therefore, LED could be used as a prior exercise strategy to modulate oxidative response acutely in targeted muscle and enhance exercise tolerance.

A new age-based equation for predicting maximum heart rate in endurance-trained runners / Uma nova equação baseada em idade para predição da frequência cardíaca máxima em corredores aerobiamente treinados / Una nueva ecuación basada en la edad para pronosticar la frecuencia cardíaca máxima en corredores entrenados en resistencia

Abstract This study aimed to generate an age-based maximum heart rate (HRmax) equation for endurance-trained runners. Thirty-four male runners performed three tests on a motorized treadmill, starting at 8 km h-1 with increments of 1 km h-1 every 1, 2 or, 3 min. HRmax was defined as the highest heart rate value recorded during each test. Post hoc analyses indicated that the HRmax derived from each test was significantly lower than the highest HRmax value, for each participant. HRmax predicted by "206 - 0.7 × age" underestimated the highest HRmax by 8.6 beats min-1. Thus, the generated age-based "218 - 0.8 × age" equation should be used to predict HRmax in endurance-trained runners.

Resumo Esse estudo objetivou gerar uma equação de frequência cardíaca máxima (FCmax) baseada na idade para corredores aerobiamente treinados. Trinta e quatro corredores homens realizaram três testes incrementais em esteira motorizada, com início a 8 km·h-1 e incrementos de 1 km·h-1 a cada um, dois ou, três minutos. A FCmax foi definida como o valor mais alto de frequência cardíaca registrado em cada teste. As análises de post hoc indicaram que a FCmax de cada teste foi significativamente menor que o valor mais elevado de FCmax para cada participante. A FCmax predita pela equação "206 - 0,7 x idade" subestimou a mais alta FCmax em 8,6 batimentos·min-1. Logo, a equação gerada baseada em idade "218 - 0,8 x idade" deveria ser usada para predizer a FCmax em corredores aerobiamente treinados.

Resumen El objetivo de este estudio fue generar una ecuación de la frecuencia cardíaca máxima (FCmáx) basada en la edad en corredores entrenados en resistencia. Treinta y cuatro corredores de sexo masculino realizaron 3 pruebas en una cinta ergométrica motorizada, comenzando con la velocidad de 8 km/h-1 con incrementos de 1 km/h-1 cada uno, 2 o 3 min. La FCmáx fue definida como el valor de la frecuencia cardíaca más elevada registrada durante cada prueba. Los análisis posteriores indicaron que la FCmáx derivada de las pruebas fue considerablemente más baja que el valor más alto de la FCmáx de cada participante. La FCmáx pronosticada por la ecuación «206-0,7 × edad¼, subestimada la más alta FCmás por 8,6 lat/min-1. Así, la ecuación generada basada en la edad «218-0,8 × edad¼ debería utilizarse para pronosticar la FCmáx en corredores entrenados en resistencia.

Photobiomodulation by Led Does Not Alter Muscle Recovery Indicators and Presents Similar Outcomes to Cold-Water Immersion and Active Recovery.

Purpose: The aim of the present study was to investigate the effectiveness of photobiomodulation therapy (PBMT) on muscle recovery based on inflammation (interleukin-10 [IL-10]; tumor necrosis factor-α [TNFα]), muscle damage markers (creatine kinase [CK]; lactate dehydrogenase [LDH]), delay onset muscle soreness (DOMS), and countermovement jump performance (CMJ) after two sprint interval training (SIT) sessions compared with a placebo condition (part-I), as well as to compare the effectiveness of PBMT with active recovery (AR) and cold-water immersion (CWI) (part-II). Methods: Part-I was conducted as a double-blind, randomized and placebo-controlled study and part-II as a parallel-group study. Thirty-six men participated in the studies (12 participants in part-I and 36 participants in part-II). Volunteers performed two SITs interspaced by 24-h (SIT1 and SIT2) to mimic the effect of accumulating 2 consecutive days of SIT. In part-I, only after SIT2, PBMT [Total energy: 600J (300J per leg in 5 spots); wavelength: 660-850 nm] or placebo interventions were performed, while in part-II PBMT (part-I data), AR (15-min; 50% of the maximal aerobic power), or CWI (10-min; 10°C) were carried out, also after SIT2. Blood samples were collected before (i.e., baseline), and 0.5, 1, 24, 48, and 72-h after SIT2, while CMJ and DOMS were measured before, 24, 48, and 72-h after SIT2. Results: In part-I, there were no interactions between PBMT and placebo conditions for any blood markers (P ≥ 0.313), DOMS (P = 0.052), and CMJ (P = 0.295). However, an effect of time was found with increases in LDH, CK, and IL-10 (P ≤ 0.043) as well as a decrease in DOMS at 72-h compared with 24-h (P = 0.012). In part-II, there were no interactions between the PBMT, AR, and CWI groups for any markers at the same moments (P ≥ 0.189) and for the peak and integral values (P ≥ 0.193), for DOMS (P = 0.314) and CMJ (P = 0.264). However, an effect of time was found with an increase in CK and IL-10 (P = 0.003), while DOMS decreased at 48 and 72-h compared with 24-h (P = 0.001). Conclusion: In summary, PBMT had no effect on inflammation, muscle damage, CMJ performance, or DOMS after two consecutive sprint interval training sessions compared to placebo, CWI, and AR strategies.

Peak velocity and its time limit are as good as the velocity associated with VO 2max for training prescription in runners.

This study compared the effects of 4 weeks of training prescribed by peak velocity (V peak ) or velocity associated with maximum oxygen uptake (vVO 2max ) in moderately trained endurance runners. Study participants were 14 runners (18-35 years) randomized into 2 groups, named group VO 2 (GVO 2 ) and group V peak (GVP). The GVO 2 had training prescribed by vVO 2max and its time limit (t lim ), whereas the GVP had training prescribed by V peak and its t lim . Four tests were performed on a treadmill: 2 maximum incremental for V peak and vVO 2max and 2 for their t lim . Performance (10 km) was evaluated on a 400 m track. Evaluations were repeated after 4 weeks of endurance training. The results showed a significant effect of training on V peak [GVP (16.7±1.2 - 17.6±1.5 km . h -1 ), GVO 2 (17.1±1.9-17.7±1.6 km·h -1 )]; vVO 2max [GVP (16.4±1.4-17.0±1.3 km·h -1 ), GVO 2 (17.2±1.7-17.5±1.9 km·h -1 )]; and 10 km performance [GVP (41.3±2.4-39.9±2.7 min), GVO 2 (40.1±3.4-39.2±2.9 min)]. The V peak highly correlated with performance in both pre- and post-training in GVP (-0.97;-0.86) and GVO 2 (-0.95;-0.94), as well as with vVO 2max in GVP (-0.82;-0.88) and GVO 2 (-0.99; -0.98). It is concluded that training prescribed by V peak promoted similar improvements compared to training prescribed by vVO 2max . The use of V peak is recommended due to its practical application and the low cost of determination.

The influence of the regression model and final speed criteria on the reliability of lactate threshold determined by the Dmax method in endurance-trained runners.

Few studies verified the reliability of the lactate threshold determined by Dmax method (LTDmax) in runners and it remains unclear the effect of the regression model and the final speed on the reliability of LTDmax. This study aimed to examine the test-retest reliability of the speed at LTDmax in runners, considering the effects of the regression models (exponential-plus-constant vs third-order polynomial) and final speed criteria (complete vs proportional). Seventeen male, recreational runners performed 2 identical incremental exercise tests, with increments of 1 km·h-1 each for 3 min on treadmill to determine peak treadmill speed (Vpeak) and lactate threshold. Earlobe capillary blood samples were collected during rest between the stages. The Vpeak was defined as the speed of the last complete stage (complete final speed criterion) and as the speed of the last complete stage added to the fraction of the incomplete stage (proportional final speed criterion). Lactate threshold was determined from exponential-plus-constant and from third-order polynomial regression models with both complete and proportional final speed criteria and from fixed blood lactate level of 3.5 mmol·L-1 (LT3.5mM). The LTDmax obtained from the exponential-plus-constant regression model presented higher reliability (coefficient of variation (CV) ≤ 3.7%) than the LTDmax calculated from the third-order polynomial regression model (CV ≤ 5.8%) and LT3.5mM (CV = 5.4%). The proportional final speed criterion is more appropriate when using the exponential-plus-constant regression model, but less appropriate when using the third-order polynomial regression model. In conclusion, exponential-plus-constant using the proportional final speed criterion is preferred over LT3.5mM and over third-order polynomial regression model to determine a reliable LTDmax.