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1.
Int. j. morphol ; 42(2)abr. 2024.
Article in English | LILACS-Express | LILACS | ID: biblio-1558121

ABSTRACT

SUMMARY: Trail running (TR), an extreme endurance sport, presents unique challenges due to the variety of terrain and distances, where physiological capacity and body composition have been considered better predictors of performance. This longitudinal case study examines the impact of training intensity distribution (TID) on an elite trail runner's physiological profile and performance over four years. Two TID models were implemented: polarized (POL) and pyramidal (PYR). Physiological assessments included maximal oxygen consumption (VO2max), lactate thresholds (LT1 and LT2), and anthropometric characteristics. The training was classified according to the 3-zone intensity model (zone 1: below the first lactate threshold; zone 2: between the first and second lactate threshold; zone 3: above the second lactate threshold). During the four years, the average TID distribution was 75 % zone 1, 18 % zone 2, and 7 % zone 3. Physiological capacity increased by 7.14 % (14 to 15 km/h) for velocity at LT1 (vLT1) and 8.13 % (16 to 17.3 km/h) for velocity at LT2 (vLT2). The most significant increases were observed during the second year when the percentage of training time in zone 1 was lower (65 %) and in zone 2 greater (30 %) than those reported in other years. Consequently, vLT1 and vLT2 increased by 3.5 % (from 14.1 to 14.6 km/h) and 3.6 % (from 16.5 to 17.1 km/h), respectively. In conclusion, this case study revealed that emphasizing training in zone 2 (moderate intensity) and increasing the training load significantly improved performance at lactate thresholds. Despite modifying body composition, no influence on improving endurance performance was observed. These findings underscore the importance of TID in elite trail runners and highlight the potential to optimize physiological adaptations and performance outcomes.


Trail running (TR), un deporte de resistencia extrema, presenta desafíos únicos debido a la variedad de terrenos y distancias, donde la capacidad fisiológica y la composición corporal se han considerado mejores predictores del rendimiento. Este estudio de caso longitudinal examina el impacto de la distribución de la intensidad del entrenamiento (TID) en el perfil fisiológico y el rendimiento de un corredor de montaña de élite durante cuatro años. Se implementaron dos modelos TID: polarizado (POL) y piramidal (PYR). Las evaluaciones fisiológicas incluyeron el consumo máximo de oxígeno (VO2max), los umbrales de lactato (LT1 y LT2) y las características antropométricas. El entrenamiento se clasificó según el modelo de intensidad de 3 zonas (zona 1: por debajo del primer umbral de lactato; zona 2: entre el primer y segundo umbral de lactato; zona 3: por encima del segundo umbral de lactato). Durante los cuatro años, la distribución TID promedio fue 75 % zona 1, 18 % zona 2 y 7 % zona 3. La capacidad fisiológica aumentó un 7,14 % (14 a 15 km/h) para la velocidad en LT1 (vLT1) y un 8,13 % (16 a 17,3 km/h) para velocidad en LT2 (vLT2). Los incrementos más significativos se observaron durante el segundo año cuando el porcentaje de tiempo de entrenamiento en la zona 1 fue menor (65 %) y en la zona 2 mayor (30 %) que los reportados en otros años. En consecuencia, vLT1 y vLT2 aumentaron un 3,5 % (de 14,1 a 14,6 km/h) y un 3,6 % (de 16,5 a 17,1 km/h), respectivamente. En conclusión, este estudio reveló que enfatizar el entrenamiento en la zona 2 (intensidad moderada) y aumentar la carga de entrenamiento mejoró significativamente el rendimiento en los umbrales de lactato. A pesar de modificar la composición corporal, no se observó influencia en la mejora del rendimiento de resistencia. Estos hallazgos subrayan la importancia del TID en los corredores de trail de élite y resaltan el potencial para optimizar las adaptaciones fisiológicas y los resultados de rendimiento.

2.
Rev. bras. cineantropom. desempenho hum ; 21: e56955, 2019. tab, graf
Article in English | LILACS | ID: biblio-1013455

ABSTRACT

Abstract The current study described the training load and intensity distribution of 30 elite Under 20 soccer players (17.9 ± 0.6 years, 180.3 ± 5.7 cm, 73.7 ± 8.8kg) from a 3-time FIFA Club World Cup champion. Session-rating of perceived exertion (s-RPE), internal training load (ITL) and monotony were recorded across 40 training sessions. Mixed-effects modeling was used for data analysis. The athletes performed 33.0 ± 6.9 out of 40 planned training sessions. Most common reasons for absence from training included sickness or minor injuries. Overall, these training sessions summed 2928.7 ± 627.6 minutes. Athletes performed significantly more training sessions at low and moderate intensity zones than at high-intensity zone (p <0.0001). The current data indicate that elite young soccer players perform their training sessions predominantly at the low-intensity zone. Training monitoring is an important aspect of the sport training process evolution. In fact, previous evidence has already shown that an appropriate intensity distribution prevents maladaptation from sports training and may optimize athletic performance. Therefore, coaches should implement strategies to monitor training loads during pre-season and competitive periods.


Resumo O presente estudo descreveu a carga de treinamento e a distribuição de intensidade de 30 jogadores de elite de futebol sub 20 (17,9 ± 0,6 anos, 180,3 ± 5,7 cm, 73,7 ± 8,8 kg) de um clube de elite do estado de São Paulo. Durante 40 sessões de treinamento, a percepção subjetiva de esforço, bem como a carga interna de treinamento e a monotonia foram registradas. Os dados foram analisados por modelagem linear mista. Os atletas realizaram 33,0 ± 6,9 das 40 sessões de treinamento planejadas. As razões mais comuns para a ausência nas sessões de treinamento incluíram doenças ou lesões leves. De forma geral, essas sessões somaram 2928,7 ± 627,6 minutos. Os atletas realizaram significativamente mais sessões de treinamento em zonas de baixa e moderada intensidade comparado com a zona de alta intensidade (p <0,0001). Os dados do presente estudo indicam que os jovens jogadores de elite realizam suas sessões de treinamento predominantemente na zona de baixa intensidade. O monitoramento do treinamento colabora para a evolução do processo de treinamento esportivo. De fato, evidências anteriores já mostraram que a distribuição de intensidade apropriada impede a mal adaptação ao treinamento esportivo e pode otimizar o desempenho atlético. Portanto, treinadores devem implementar estratégias para monitorar as cargas de treinamento durante os períodos de pré-temporada e de competição.


Subject(s)
Physical Endurance , Soccer , Task Performance and Analysis
3.
Chinese Journal of Radiological Medicine and Protection ; (12): 145-149, 2018.
Article in Chinese | WPRIM | ID: wpr-708031

ABSTRACT

Objective To determine the optimal electron beam energy at different field size through a Monte Carlo-based simulation of the therapy head of Varian X 6 MV linear accelerator so as to study the influence of radial intensity on depth dose.Methods Firstly,keeping the radial intensity unchanged for the field of interest while changing electron beam energy,compassion was carried out of calculated percentage depth doses between measured values.Thus,the optimal energy was identified for this field size.Then,the obtained energy was set the optimal value to study the radial intensity influence on the depth doses.Results The optimal electron energy for 4 cm ×4 cm,10 cm × 10 cm,20 cm × 20 cm and 30 cm × 30 cm field sizes was 5.9,6.0,6.3 and 6.4 MeV respectively.Changes in radial intensities resulted in negligible changes in percentage depth doses for4 cm ×4-cm and 10 cm × 10 cm fields,but led to observable discrepancy for 20 cm × 20 cm and 30 cm × 30 cm fields.Conclusions The optimal electron energies for different field sizes are slightly different.Change in radial intensity distribution has significant influence on the depth dose for large field.To improve simulation accuracy,the field size needs to be taken into consideration in determining the electron beam energy and radial intensity distribution.

4.
International Journal of Biomedical Engineering ; (6): 14-17, 2012.
Article in Chinese | WPRIM | ID: wpr-424883

ABSTRACT

Objective To design a new method of determining optical properties of biological tissue by measuring light intensity distribution.Methods The light distribution in Intralipid-10% suspension at 650 nm was measured by optical fiber probe.The optical parameters were derived from nonlinear regression of the diffusion equation for intensity.The distribution and anisotropy of intensity was abtained by the determined optical parameters and the diffusion equation for intensity.ResultsThis new method was feasible by comparing the experimental data with published results.ConclusionThe experiment results would provide useful information for radiative transfer equation,marine optical remote sensing measurement and laser therapeutic applications.-

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