Injury epidemiology in competing and non-competing spanish crossfit® practitioners / Epidemiología lesional en practicantes de crossfit® competidores y no competidores españoles

La falta de estudios sobre lesiones en Crossfit® en España, motiva la realización de este estudio epidemiológico descriptivo, observacional y retrospectivo, analizando la incidencia y las características de las lesiones sufridas por practicantes de Crossfit® competidores y no competidores. Se registraron las lesiones sufridas por 434 deportistas entre el 1 de enero y el 31 de diciembre de 2019. Se registraron datos sobre el número de lesiones, lesiones más frecuentes, distribución, tipo, ubicación, el momento en que ocurrieron y la causa de las lesiones que afectan el sistema musculoesquelético. La tasa de lesiones en esta población fue de 3,48 lesiones por 1000 horas de exposición al riesgo. El hombro y la zona lumbar fueron las zonas anatómicas más frecuentemente lesionadas, siendo el musculo y el tendón el tejido de asiento más habitual de las lesiones. El Powerlifting fue la actividad más lesiva. (AU)

The lack of studies on Crossfit® injuries in Spain, motivates the realization of this descriptive, observational and retrospective epidemiological study, analyzing the incidence and characteristics of injuries suffered by Crossfit® competitors and non-competitors.The injuries suffered by 434 athletes between from January 1st to December 31st 2019 were recorded. We collected data on the number of injuries, the most frequent injuries, their distribution, type, location, the moment at which these occurred and the cause of the injuries affecting the musculoeskeletal system. We found that the injury rate in this population was 3,48 injuries per 1000 hours of risk. The shoulder and lumbar area were the most frequently injured anatomical areas, with muscle and tendon being the most common seat tissue of injuries. Powerlifting was the most damaging activity. (AU)

Understanding the meaning of lactate threshold in resistance exercises.

This study compares acute cardiorespiratory, metabolic, mechanical and rating of perceived effort (RPE) responses to 2 different prolonged constant-load exercises, half-squat (HS) and cycle ergometry, performed at a workload corresponding to the lactate threshold (LT). A total of 18 healthy subjects completed 5 exercise tests separated by 48 h rest periods: an incremental cycle ergometer test, a constant-load cycle ergometer test at LT intensity, a one-repetition maximum (1RM) HS test, an incremental HS test and a constant-load HS test at LT intensity. In both constant-load tests, cardiorespiratory, metabolic and RPE data were recorded. Mechanical responses before and after each test were assessed in terms of jump height and mean power measured in a counter movement jump (CMJ) test. In both exercises, cardiorespiratory and metabolic responses stabilized, though cardiorespiratory responses were significantly greater for cycle ergometry (P<0.001), with the exception of respiratory exchange ratio (RER), which was higher for HS (P=0.028). Mechanical fatigue was observed in only HS (P<0.001). In conclusion, different exercise modalities induced different yet stable acute cardiorespiratory and metabolic responses. Although such responses were significantly reduced in HS, greater mechanical fatigue was produced, most likely because of the particular muscle actions involved in this form of exercise.