Effects of different exercise intensities of race-walking on brain functional connectivity as assessed by functional near-infrared spectroscopy.

Introduction: Race-walking is a sport that mimics normal walking and running. Previous studies on sports science mainly focused on the cardiovascular and musculoskeletal systems. However, there is still a lack of research on the central nervous system, especially the real-time changes in brain network characteristics during race-walking exercise. This study aimed to use a network perspective to investigate the effects of different exercise intensities on brain functional connectivity. Materials and methods: A total of 16 right-handed healthy young athletes were recruited as participants in this study. The cerebral cortex concentration of oxyhemoglobin was measured by functional near-infrared spectroscopy in the bilateral prefrontal cortex (PFC), the motor cortex (MC) and occipital cortex (OC) during resting and race-walking states. Three specific periods as time windows corresponding to different exercise intensities were divided from the race-walking time of participants, including initial, intermediate and sprint stages. The brain activation and functional connectivity (FC) were calculated to describe the 0.01-0.1 Hz frequency-specific cortical activities. Results: Compared to the resting state, FC changes mainly exist between MC and OC in the initial stage, while PFC was involved in FC changes in the intermediate stage, and FC changes in the sprint stage were widely present in PFC, MC and OC. In addition, from the initial-development to the sprint stage, the significant changes in FC were displayed in PFC and MC. Conclusion: This brain functional connectivity-based study confirmed that hemodynamic changes at different exercise intensities reflected different brain network-specific characteristics. During race-walking exercise, more extensive brain activation might increase information processing speed. Increased exercise intensity could facilitate the integration of neural signals such as proprioception, motor control and motor planning, which may be an important factor for athletes to maintain sustained motor coordination and activity control at high intensity. This study was beneficial to understanding the neural mechanisms of brain networks under different exercise intensities.

Postexercise Hot-Water Immersion Does Not Further Enhance Heat Adaptation or Performance in Endurance Athletes Training in a Hot Environment.

PURPOSE: Hot-water immersion (HWI) after training in temperate conditions has been shown to induce thermophysiological adaptations and improve endurance performance in the heat; however, the potential additive effects of HWI and training in hot outdoor conditions remain unknown. Therefore, this study aimed to determine the effect of repeated postexercise HWI in athletes training in a hot environment. METHODS: A total of 13 (9 female) elite/preelite racewalkers completed a 15-day training program in outdoor heat (mean afternoon high temperature = 34.6°C). Athletes were divided into 2 matched groups that completed either HWI (40°C for 30-40 min) or seated rest in 21°C (CON), following 8 training sessions. Pre-post testing included a 30-minute fixed-intensity walk in heat, laboratory incremental walk to exhaustion, and 10,000-m outdoor time trial. RESULTS: Training frequency and volume were similar between groups (P = .54). Core temperature was significantly higher during immersion in HWI (38.5 [0.3]) than CON (37.8°C [0.2°C]; P < .001). There were no differences between groups in resting or exercise rectal temperature or heart rate, skin temperature, sweat rate, or the speed at lactate threshold 2, maximal O2 uptake, or 10,000-m performance (P > .05). There were significant (P < .05) pre-post differences for both groups in submaximal exercising heart rate (∼11 beats·min-1), sweat rate (0.34-0.55 L·h-1) and thermal comfort (1.2-1.5 arbitrary units), and 10,000-m racewalking performance time (∼3 min). CONCLUSIONS: Both groups demonstrated significant improvement in markers of heat adaptation and performance; however, the addition of HWI did not provide further enhancements. Improvements in adaptation appeared to be maximized by the training program in hot conditions.

From Passive Patient to Engaged Partner: My Journey With Parkinson Disease.

This patient narrative by Richard Higgins with Maureen Hennessey describes Richard's journey of learning to live with a chronic and progressive illness. It begins with Richard's diagnosis and shares many of the lessons learned along the way. Richard copes daily with this condition, relying on the support and expertise of his wife and the treatment team he has assembled while also encouragingly drawing on the skills and knowledge gained as a longtime running coach. A clinical commentary is provided at the article's conclusion, drafted by Richard's friend, Maureen Hennessey, PhD, CPCC, CPHQ, offering observations about the relevance of Richard's story to participatory medicine and suggesting pertinent resources for patients and health care professionals.

Análisis pre mundial del paso de un marchista de élite en pista electrónica / Análise prémundial do passo de um marchista de elite em pista eletrônica / Pre-world analysis of the step of an elite marchist on an electronic track

Problema: en el mundial, los marchistas participan con el más alto nivel de ejecución técnica y con las mejores condiciones físicas, por lo que el análisis de los pasos de un marchista es clave para la obtención de un resultado óptimo. Objetivo: analizar la técnica del paso de un marchista de elite y el comportamiento de las variables de la marcha atlética, pre competencia al mundial de atletismo. Método: al deportista se le aplicó una prueba en una pista electrónica, evaluando las variables cinemáticas: longitud de paso, frecuencia de pasos, tiempo de vuelo y velocidad. Se utilizó ANOVA para determinar diferencias significativas (p ≤0.05). Resultados: en las tres pruebas realizadas, todas las variables incrementaron significativamente, aunque la diferencia más significativa se encontró entre tiempo de vuelo y frecuencia de pasos p=0.0000001, p<0.05. Conclusión: debido a que el tiempo de vuelo se incrementa rápidamente, se debe cuidar que no influya en la ejecución técnica del marchista para que sea más efectiva y así evitar una amonestación o descalificación.

Problem: In the World Athletics Championships, the racewalkers participate with the highest level of technical execution and with the best physical conditions, so the analysis of the steps of a racewalker is key to obtain an optimal result. Objective: To analyze the technique of an elite racewalker and the behavior of the variables of the athletic racewalking, pre-competition to the World Athletics Championships. Method: A test on an electronic track was given to one athlete, evaluating the kinematic variables: step length, step frequency, flight time, and speed. ANOVA was used to determine significant differences (p ≤0.05). Result: In the three tests carried out, all the variables increased significantly, although the most significant difference was found between flight time and step frequency p = 0.0000001, p <0.05. Conclusion: Since the flight time increases rapidly, it must be careful that this not influence the technical execution of the racewalkers, to be more effective, and thus avoid a warning or disqualification.

Problema: No mundial, os marchistas participam com o maior nível de execução técnica e com as melhores condições físicas, é por isso que a análise dos passos de um marchista é a chave para a obtenção de melhores resultados. Objetivo: analisar a técnica de passo de um marchista de elite e o comportamento das variáveis da marcha atlética, pré-competição rumo ao mundial de atletismo. Método: um teste foi aplicado em uma pista eletrônica de um marchista e se estudaram as seguintes variáveis cinemáticas: o comprimento do passo, a frequência de passos, o tempo de voo e a velocidade. ANOVA foi utilizada para determinar as diferenças significativas (p ≤0.05). Resultados: Em todos os três testes realizados, todas as variáveis aumentaram significativamente, embora a diferença mais significativa foi encontrada entre o tempo de voo e a frequência de passos p = 0.0000001, p <0,05. Conclusão: Porque o tempo de voo aumenta rapidamente, deve ser assegurado que não tenha nenhuma influência sobre a execução técnica do marchista, para que seja mais eficaz e, assim, evitar uma advertência ou desqualificação.

Changes in movement organization and control strategies when learning a biomechanically constrained gait pattern, racewalking: a PCA study.

Combining advances from gait analysis and motor learning fields, this study aims to examine invariant characteristics and practice-related changes in the control of walking gait when learning a biomechanically constrained pattern, racewalking (RW). RW's regulation imposes a straightened knee at the stance phase which differentiates it qualitatively from normal walking. Using 3D motion analysis, we computed key kinematic variables from a whole-body model. Principal component analysis was then used as a tool to evaluate the evolution of normal walking synergies (S0) immediately at the first practice session (S1) and further with practice (S1-S4). Before the start of practice, normal walking was characterized by two predominant control dimensions explaining an upper-extremities/antero-posterior component (PC1) and a lower-extremities/vertical component (PC2). Compared to normal walking, the immediate increase at S1 in the number of PCs needed to explain a significant portion of movement variance could be suggestive of a recruitment of a task-specific component. With practice, the significant decrease in the variance accounted for by PC1 and in the correlations between many variables could indicate a destabilization of spontaneous tendencies to facilitate the adoption of more task-specific coordinative pattern. PC2 seemed to be reinforced with practice where a significant increase in its explained variance was observed. In sum, this study shows that common features in the gait control are preserved with practice, and the movement reorganization, however, seems rather defined by shifts in the relative contribution of some variables within each PC.

Mechanical and neural function of triceps surae in elite racewalking.

Racewalking is a unique event combining mechanical elements of walking with speeds associated with running. It is currently unclear how racewalking technique impacts lower limb muscle-tendon function despite the relevance of this to muscle economy and overall performance. The present study examined triceps surae neuromechanics in 11 internationally competitive racewalkers (age 25 ± 11 yr) walking and running on a treadmill at speeds between 4.5 and 13.8 km/h while triceps surae fascicle lengths, electromyography, and kinematic data were recorded. Cumulative muscle activity required to traverse a unit distance (CMAPD) was calculated for each muscle. Medial gastrocnemius (MG) and soleus fascicle lengths/velocities were determined using an automated tracking algorithm, and muscle-tendon unit lengths were determined. Running was associated with net shortening of muscle fascicles during stance, combined with substantial lengthening of the muscle-tendon unit, implying energy storage in the Achilles tendon. When the same participants racewalked at the same speed, the fascicles shortened (soleus) or lengthened (MG), coinciding with rapid shortening followed by a relatively small increase in muscle-tendon length during stance. Consequently, compared with running at the same speed, racewalking decreased the energy-saving role of the Achilles tendon. Moreover, CMAPD was generally highest in racewalking, implying that in individual muscles, the energy cost of racewalking was higher than running. Together these results suggest that racewalking is neurally and mechanically costly relative to running at a given speed. As racewalking events are typically between 10 and 50 km, neuromechanical inefficiencies that occur with each stride likely result in substantial energetic penalties.

Kinematics of the forefoot in the horizontal plane during progressive pace barefoot racewalking on a treadmill after aerobic exercise load.

[Purpose] The aim of this study was to measure the changes in forefoot maximum medial/lateral rotation in the horizontal plane during progressive pace barefoot racewalking on a treadmill after a physically demanding aerobic exercise load (a fatigue protocol). [Subjects] Eleven junior racewalking men participated in this study. [Methods] To identify changes in forefoot maximum medial/lateral rotation in the horizontal plane after physically demanding aerobic exercise load, an 8 ch wireless Motion Recorder (MVP-RF8-BC) was utilized. [Results] Forefoot maximum medial/lateral rotation in the horizontal plane was significantly associated with increased paces during progressive pace treadmill racewalking. Significant increases in forefoot maximum medial/lateral rotation were observed during progressive pace barefoot racewalking on the instrumented treadmill at 8 km/h and 10 km/h after a physically demanding aerobic exercise load. [Conclusion] The findings of this study indicated that forefoot maximum medial/lateral rotation increased during progressive pace barefoot racewalking in the fatigue state after a physically demanding aerobic exercise load, which implies that the kinematic features of the forefoot are changed in the fatigue state.

PHYSIOLOGICAL STUDY OF RACE-WALKING / 体力科学

The purpose of this study was to clarify some of the characteristics of race-walking, especially the relationship between walking speed and oxygen requirement, and stride in race-walking and normal walking, and to examine whether race-walking is effective for the maintenance and promotion of health.<BR>The subjects were five male race-walkers (race-walker group) and five male college students (control group) .<BR>The results obtained were as follows:<BR>1. Under race-walk conditions, the highest speeds attained in the race-walker and control groups were 200-220 m/min and 160 m/min, respectively. Under normal walking conditions, however, the values were 140 m/min in both groups.<BR>2. A lower oxygen requirement was observed at slower speed during normal walking and at a higher speed (over 130 m/min) during race-walking.<BR>3. Oxygen requirement (ml/kg/100 m) in the race-walker group was minimal at 60-80 m/min during race-walking and at 60 m/min during normal walking. Values in the control group were minimal at 60 m/min under both walking conditions.<BR>4. The oxygen requirement in the race-walker group was less than that of the control group under both walking conditions.<BR>5. Under normal walking conditions, as the speed increased, both step-length and step frequency gradually increased, until step-length reached a limit of 80 cm. Thereafter, walking was maintained only by an increase in step frequency. However, in the race-walkes group, the subjects were capable of increasing their step-length further, and maintaining a higher speed (up to 220 m/min) .<BR>6. It was suggested that race-walking is one of the most efficient exercises for maintaining and improving health.

Physiological study of race-walking. The relationship between walking speed and oxygen requirement / 体力科学

The purpose of this study was to clarify some of the characteristics of race-walking, especially the relationship between walking speed and oxygen requirement, and stride in race-walking and normal walking, and to examine whether race-walking is effective for the maintenance and promotion of health.<BR>The subjects were five male race-walkers (race-walker group) and five male college students (control group) .<BR>The results obtained were as follows:<BR>1. Under race-walk conditions, the highest speeds attained in the race-walker and control groups were 200-220 m/min and 160 m/min, respectively. Under normal walking conditions, however, the values were 140 m/min in both groups.<BR>2. A lower oxygen requirement was observed at slower speed during normal walking and at a higher speed (over 130 m/min) during race-walking.<BR>3. Oxygen requirement (ml/kg/100 m) in the race-walker group was minimal at 60-80 m/min during race-walking and at 60 m/min during normal walking. Values in the control group were minimal at 60 m/min under both walking conditions.<BR>4. The oxygen requirement in the race-walker group was less than that of the control group under both walking conditions.<BR>5. Under normal walking conditions, as the speed increased, both step-length and step frequency gradually increased, until step-length reached a limit of 80 cm. Thereafter, walking was maintained only by an increase in step frequency. However, in the race-walkes group, the subjects were capable of increasing their step-length further, and maintaining a higher speed (up to 220 m/min) .<BR>6. It was suggested that race-walking is one of the most efficient exercises for maintaining and improving health.