Physical Fitness Parameters of Elite Chinese Male Canoe Slalom Paddlers / Parámetros de Aptitud Física de los Remeros Masculinos Chinos de Élite en Canoa Slalom

SUMMARY: This study aimed to investigate the physical fitness parameters of elite Chinese male canoe slalom athletes and explore the corresponding training strategies. Eight elite male slalom kayakers from the Chinese national team were selected as research subjects. The following parameters were measured: age, height, weight, body mass index (BMI), arm span, upper arm circumference, body fat percentage, maximum oxygen uptake, heart rate, blood lactic acid level, upper limb strength, and 300-m linear speed in flat water. Compared with elite international male slalom athletes, elite Chinese male slalom athletes had lower values for age, height, weight, BMI, arm span, and upper arm circumference, while body fat percentage, bench push, and bench pull values were greater, and the 300 m straight-line speed in flat water was slower. From an athlete development and physical training perspective, elite Chinese male slalom athletes should prioritize the accumulation of competitive experience instead of increasing training years in order to swiftly reach top international standards. Additionally, these athletes should manage their body fat percentage and improve their aerobic capacity, paddling skills, mechanical work, and linear speed in flat water.

Este estudio tuvo como objetivo investigar los parámetros de aptitud física de los atletas masculinos chinos de élite de canoa slalom y explorar las estrategias de entrenamiento correspondientes. Ocho hombres kayakistas de élite de slalom del equipo nacional chino fueron seleccionados como sujetos de investigación. Se midieron los siguientes parámetros: edad, talla, peso, índice de masa corporal (IMC), envergadura, perímetro braquial, porcentaje de grasa corporal, consumo máximo de oxígeno, frecuencia cardiaca, nivel de ácido láctico en sangre, fuerza de los miembros superiores y carrera de 300 m y velocidad lineal en agua plana. En comparación con los atletas internacionales masculinos de slalom de élite, los atletas chinos de slalom masculinos de élite tenían valores más bajos para la edad, la altura, el peso, el IMC, la envergadura del brazo y la circunferencia del brazo superior, mientras que los valores de porcentaje de grasa corporal, empuje de banco y tirón de banco eran mayores y la velocidad en línea recta de 300 m en aguas planas fue más lenta. Desde la perspectiva del desarrollo del atleta y el entrenamiento físico, los atletas de slalom masculinos chinos de élite deberían priorizar la acumulación de experiencia competitiva en lugar de aumentar los años de entrenamiento para alcanzar rápidamente los más altos estándares internacionales. Además, estos atletas deben controlar su porcentaje de grasa corporal y mejorar su capacidad aeróbica, habilidades de remo, trabajo mecánico y velocidad lineal en aguas tranquilas.

Corrigendum: Impact of climate change and rubber (Hevea brasiliensis) plantation expansion on reference evapotranspiration in Xishuangbanna, Southwest China.

[This corrects the article DOI: 10.3389/fpls.2022.830519.].

Impact of Climate Change and Rubber (Hevea brasiliensis) Plantation Expansion on Reference Evapotranspiration in Xishuangbanna, Southwest China.

The expansion of rubber (Hevea brasiliensis) cultivation plantation over the past few decades has been significantly explosive in Xishuangbanna, southwest China. More and more evidences concerning the expansion of rubber plantations lead to the negative influence to local regional hydrology. It is vital to explore the impact of climate change and rubber (Hevea brasiliensis) plantation expansion on reference evapotranspiration (ET0) for the sustainable and efficient use of regional water resources. In this study, the spatiotemporal variation of ET0 as well as its relationship in rubber plantations area in Xishuangbanna from 1970-2017 were analyzed by using trend, correlation and contribution analysis. The results showed that the rubber plantation was 12,768 ha yr-1 from 1990 to 2017 in Xishuangbanna, and nearly 40.8% of new rubber plantations expanded above 900 m in altitude from 2000 to 2017. Sunshine duration and average relative humidity were the key meteorological factors that affect ET0 in Xishuangbanna, with the sensitivity coefficient of 0.51 and 0.35, respectively. The multiyear relative change of ET0 in Xishuangbanna was 9.18%, and the total contribution of major climate factors was 7.87% during 1970 and 2017. The average relative humidity in the plantation area decreases, which directly leads to the increase of ET0. The amount of ET0 change from 2000 to 2017 affected by climate change increased at 3.13 mm/10a, whereas it was 2.17 mm/10a affected by the expansion of rubber plantations by quantitative separation. ET0 was significantly affected by climate change but intensified by the expansion of rubber plantation.

Corrigendum: Impact of climate change and rubber (Hevea brasiliensis) plantation expansion on reference evapotranspiration in Xishuangbanna, Southwest China.

[This corrects the article DOI: 10.3389/fpls.2022.830519.].

An Electronic Health Record-based Algorithm to Ascertain the Date of Second Breast Cancer Events.

OBJECTIVES: Studies of cancer recurrences and second primary tumors require information on outcome dates. Little is known about how well electronic health record-based algorithms can identify dates or how errors in dates can bias analyses. RESEARCH DESIGN: We assessed rule-based and model-fitting approaches to assign event dates using a previously published electronic health record-based algorithm for second breast cancer events (SBCE). We conducted a simulation study to assess bias due to date assignment errors in time-to-event analyses. SUBJECTS: From a cohort of 3152 early-stage breast cancer patients, 358 women accurately identified as having had an SBCE served as the basis for this analysis. MEASURES: Percent of predicted SBCE dates identified within ±60 days of the true date was the primary measure of accuracy. In the simulation study, bias in hazard ratios (HRs) was estimated by averaging the difference between HRs based on algorithm-assigned dates and the true HR across 1000 simulations each with simulated N=4000. RESULTS: The most accurate date algorithm had a median difference between the true and predicted dates of 0 days with 82% of predicted dates falling within 60 days of the true date. Bias resulted when algorithm sensitivity and specificity varied by exposure status, but was minimal when date assignment errors were of the magnitude observed for our date assignment method. CONCLUSIONS: SBCE date can be relatively accurately assigned based on a previous algorithm. While acceptable in many scenarios, algorithm-assigned dates are not appropriate to use when operating characteristics are likely to vary by the study exposure.