Trail running injury risk factors: a living systematic review

ObjectiveTo review and frequently update the available evidence on injury risk factors and epidemiology of injury in trail running.DesignLiving systematic review. Updated searches will be done every 6 months for a minimum period of 5 years.Data sourcesEight electronic databases were searched from inception to 18 March 2021.Eligibility criteriaStudies that investigated injury risk factors and/or reported the epidemiology of injury in trail running.ResultsNineteen eligible studies were included, of which 10 studies investigated injury risk factors among 2 785 participants. Significant intrinsic factors associated with injury are: more running experience, level A runner and higher total propensity to sports accident questionnaire (PAD-22) score. Previous history of cramping and postrace biomarkers of muscle damage is associated with cramping. Younger age and low skin phototypes are associated with sunburn. Significant extrinsic factors associated with injury are neglecting warm-up, no specialised running plan, training on asphalt, double training sessions per day and physical labour occupations. A slower race finishing time is associated with cramping, while more than 3 hours of training per day, shade as the primary mode of sun protection and being single are associated with sunburn. An injury incidence range 0.7–61.2 injuries/1000 hours of running and prevalence range 1.3% to 90% were reported. The lower limb was the most reported region of injury, specifically involving blisters of the foot/toe.ConclusionLimited studies investigated injury risk factors in trail running. Our review found eight intrinsic and nine extrinsic injury risk factors. This review highlighted areas for future research that may aid in designing injury risk management strategies for safer trail running participation.PROSPERO registration numberCRD42021240832.

Epidemiology, Clinical Characteristics, and Risk Factors for Running-Related Injuries among South African Trail Runners

Trail running involves running on varying natural terrains, often including large elevation gains/losses. Trail running has a high risk of injury, and runners often participate in remote regions where medical support is challenging. The aim of this study was to determine the epidemiology, clinical characteristic, and associated injury risk factors among trail runners. A modified Oslo Sports Trauma Research Center Questionnaire for Health Problems (OSTRC-H) was used biweekly to collect running-related injury (RRI) and training history data prospectively, among 152 participants (males n = 120, females n = 32) over 30 weeks. We report an overall injury rate of 19.6 RRIs per 1000 h and an RRI mean prevalence of 12.3%. The leading anatomical site of RRIs was the lower limb (82.9%), affecting the knee (29.8%), shin/lower leg (18.0%), and the foot/toes (13.7%). A history of previous RRI in the past 12 months (p = 0.0032) and having a chronic disease (p = 0.0188) are independent risk factors for RRIs among trail runners. Two in three trail runners sustain an RRI mainly affecting the knee, shin/lower leg, and foot/toes. A history of previous RRI in the past 12 months and a having chronic disease is independently associated with RRI among trail runners. These results could be used to develop future RRI prevention strategies, combined with clinical knowledge and experience.

Outpatient Assessment of Mechanical Load, Heat Strain and Dehydration as Causes of Transitional Acute Kidney Injury in Endurance Trail Runners

Background: This study aimed to globally assess heat strain, dehydration, and mechanical load as acute kidney injury (AKI) indicators in amateur endurance trail athletes during a 35.3 km run. Methods: Thirty amateur experienced trail runners completed an endurance trail run (total positive ascend 1815 m). The following assessments were performed at four measurement time points (pre-, during, immediately post [-post0h], and after 24 h of the finish of the run [-post24h]): serum test (creatinine, blood ureic nitrogen, albumin, creatine kinase, blood ureic nitrogen: creatinine ratio, creatinine clearance, and glomerular filtration rate), mechanical load (impacts and Player Load), heat strain and dehydration (hematocrit, urine solids, body weight and urine specific gravity), pain and exertion perception (rate of perceived exertion, lumbar and bipodal, and one-leg squat pain), and urinalysis (pH, protein, glucose, erythrocytes, and urine specific gravity). Results: There were pre vs. post0h changes in all serum biomarkers (F = 5.4–34.45, p < 0.01). The change in these biomarkers correlated with an increase in mechanical load indicators (r = 0.47–59, p < 0.05). A total of 40% and 23.4% of participants presented proteinuria and hematuria, respectively. Pain and perceived exertion increased significantly due to effort made during the endurance trail running (F = 4.2–176.4, p < 0.01). Conclusions: Endurance trail running may lead to an increase in blood and urine indicators of transitional AKI. The difference in blood and urine markers was significantly related to the mechanical load during running, suggesting potential kidney overload and cumulative mechanical load.

Racing and Training Demands of off-Road Triathlon: A Case Study of a National Champion Masters Triathlete

(1) Background: This report examines the unique demands of off-road triathlon (XT) by presenting physiological, field, and race data from a national champion off-road triathlete using several years of laboratory and field data to detail training and race intensity. (2) Methods: Laboratory and field data were collected when the athlete was at near peak fitness and included oxygen consumption (VO2), heart rate (HR), power output (W), and blood lactate (BLC) during cycling and running, while HR, cycling W, and running metrics were obtained from training and race data files over a period of seven years. Intensity was described using % HR max zones (Z) 1 &amp;lt; 75%, 2 = 75 - 87%, and Zone 3 &amp;gt; 87%, and W. An ordinary least squares analysis was used to model differences between event types. (3) Results: Weather conditions were not different across events. XT events had twice the elevation change (p&amp;lt;0.01) and two-three times greater W&rsquo; (p&amp;lt; 0.001) than road triathlon (ROAD), but similar HR intensity profiles (max, avg, and zones); both events are predominately performed at &amp;gt; Z2 or higher intensity. Championship XT events were longer (p&amp;lt;0.01) , with higher kJ expenditure (p&amp;lt;0.001). OLS modelling suggested three variables were strongly related (R2 = 0.84; p &amp;lt; 0.0001) to cycling performance: event type (XT vs ROAD), total meters climbed, and total bike duration. Championship XT runs were slower than either regional (p&amp;lt;0.05) or ROAD (p&amp;lt;0.01) runs, but HR intensity profiles similar. OLS modelling indicates that slower running is linked to either greater total bike kJ expenditure (R2 = 0.57; p&amp;lt;0.001), or total meters gained (R2 = 0.52; p&amp;lt;0.001). Race simulation data support these findings but failed to produce meaningful differences in running. Conclusions: XT race demands are unique and mirror MTB and trail running demands. XT athletes must be mindful of developing anaerobic fitness, technical ability, and aerobic fitness, all of which contribute to off-road cycling economy. It is unclear whether XT cycling affects subsequent running performance different from ROAD cycling.

Relación del consumo máximo de oxígeno en diferentes modelos de planificación y su uso en el trail running

El entrenamiento en bloques consiste en aplicar cargas concentradas en una o máximo dos capacidades físicas, con el propósito de maximizarlas y potenciarlas a corto tiempo cubriendo las variadas competencias. Ahora bien, el entrenamiento por medio de la planificación tradicional abarca mayores contenidos en tiempos más prolongados, alcanzando la mejora de la forma deportiva orientada hacia una sola competencia. El trail running (TR), es un deporte moderno actualmente poco estudiado, que consiste en correr por senderos, caminos y montañas, de clasificación individual y de largo aliento con similitudes de fondo, con un requerimiento mayor del desarrollo fisiológico asociado principalmente al VO2MAX. Por tanto, el objetivo de este artículo es revisar en la literatura la comparación que se pueden dar en relación con una periodización tradicional y una en bloques en cuanto a las posibles adaptaciones del VO2MAX en los deportes de resistencia de larga duración y su aplicabilidad al TR.

Peripheral Alterations Affect the Loss in Force after a Treadmill Downhill Run

Downhill running has an important effect on performance in trail running competitions, but it is less studied than uphill running. The purpose of this study was to investigate the cardiorespiratory response during 15 minutes of downhill running (DR) and to evaluate the neuromuscular consequences in a group of trail runners. Before and after a 15-min DR trial (slope: −25%) at ~60% of maximal oxygen consumption (V̇O2max), we evaluated maximal voluntary contraction torque (MVCt) and muscle contractility in a group of seventeen trail running athletes. Additionally, during the DR trial, we measured V̇O2 and heart rate (HR). V̇O2 and HR increased as a function of time, reaching +19.8 ± 15.9% (p < 0.001; ES: 0.49, medium) and +15.3 ± 9.9% (p < 0.001; ES: 0.55, large), respectively, in the last minute of DR. Post-exercise, the MVCt decreased (−22.2 ± 12.0%; p < 0.001; ES = 0.55, large) with respect to the pre-exercise value. All the parameters related to muscle contractility were impaired after DR: the torque evoked by a potentiated high frequency doublet decreased (−28.5 ± 12.7%; p < 0.001; ES: 0.61, large), as did the torque response from the single-pulse stimulation (St, −41.6 ± 13.6%; p < 0.001; ES: 0.70, large) and the M-wave (−11.8 ± 12.1%; p < 0.001; ES: 0.22, small). We found that after 15 min of DR, athletes had a decreased MVCt, which was ascribed mainly to peripheral rather than central alterations. Additionally, during low-intensity DR exercise, muscle fatigue and exercise-induced muscle damage may contribute to the development of O2 and HR drift.

Carreras por montaña en la Comunitat Valenciana (1995-2019). Evolución, distribución territorial e incidencia en áreas naturales protegidas / / / \ \ \ Mountain races in the Valencian Community (1995-2019). Evolution, territorial distribution and incidence in protected areas

Resumen: El rápido crecimiento de las carreras por montaña, ha motivado durante los últimos años su estudio. Aun son pocas las referencias bibliográficas que podemos encontrar a escala local, aunque algunas a nivel de España. Existen diferencias regionales, que demandan la necesidad de examinar este tipo de pruebas a una escala detallada. La Comunitat Valenciana, dada su extensión forestal y porcentaje de territorio montañoso (56 %), el número de espacios naturales (646) y superficie total protegida (40 %), se convierte en un buen ámbito de estudio. Una revisión bibliográfica y un análisis de la información recogida ha permitido determinar el número y la evolución de esta práctica en los últimos 25 años, la distribución espacial y temporal, y otras características de interés, como la tipología y los actores que intervienen. La tendencia a realizar este tipo de actividades dentro de Espacios Naturales Protegidos, incita a conocer el alcance que reciben diferentes áreas protegidas, elegidas para el estudio, que vistos los resultados es bastante significativo. Surge entonces la necesidad de plantearse, si los métodos de gestión y regulación son adecuados. El objetivo no es prohibir las carreras por montaña, puesto que desde una perspectiva social y económica aportan muchos beneficios, sino hacer compatible su desarrollo con los valores de conservación y protección de los espacios naturales. Palabras clave: Carreras por montaña, Comunidad Valenciana, Espacios Naturales Protegidos, Impacto ambiental. Abstract: The fast increase of the mountain races events, has motivated recently the appearance of several studies. Still are few the available references at local scale, although some at Spanish level. There are regional differences that enhance the need of study that king of events in a local scale. The Comnunitat Valenciana, with large forested mountain areas (56 %), the number of natural reserves (646) and total protected proportion (40 %), becomes a good case of study. A literature review and an analysis of the collected information allowed to know the figures an evolution of the that practice during the last 25 years, its spatial and temporal distribution, among other relevant characteristics, like the kind of events and involved actors. The tendency to organize that kind of events on Natural Protected Areas enhance the needs of evaluation of the affection to that areas, chosen for this paper, that seem clearly significative. The need arises then to consider whether the management and regulation methods are adequate. The objective is not to limit the mountain races, since from a social and economic perspective they provide many benefits, but to make their existence compatible with the protection and conservation of the natural areas. Key words: Trail running, Valencia Autonomous Region, Natural protected areas, Environmental impact.