Changes in running economy following downhill running     

Chen TC  Nosaka K  Tu JH 《Journal of sports sciences》2007,25(1):55-63

In this study, we examined the time course of changes in running economy following a 30-min downhill (-15%) run at 70% peak aerobic power (VO2peak). Ten young men performed level running at 65, 75, and 85% VO2peak (5 min for each intensity) before, immediately after, and 1 - 5 days after the downhill run, at which times oxygen consumption (VO2), minute ventilation, the respiratory exchange ratio (RER), heart rate, ratings of perceived exertion (RPE), and blood lactate concentration were measured. Stride length, stride frequency, and range of motion of the ankle, knee, and hip joints during the level runs were analysed using high-speed (120-Hz) video images. Downhill running induced reductions (7 - 21%, P < 0.05) in maximal isometric strength of the knee extensors, three- to six-fold increases in plasma creatine kinase activity and myoglobin concentration, and muscle soreness for 4 days after the downhill run. Oxygen consumption increased (4 - 7%, P < 0.05) immediately to 3 days after downhill running. There were also increases (P < 0.05) in heart rate, minute ventilation, RER, RPE, blood lactate concentration, and stride frequency, as well as reductions in stride length and range of motion of the ankle and knee. The results suggest that changes in running form and compromised muscle function due to muscle damage contribute to the reduction in running economy for 3 days after downhill running.  相似文献   

Applying the DT-CDIO engineering design model in a flipped learning programming course     

Lai  Chin-Feng  Zhong  Hua-Xu  Chang  Jui-Hung  Chiu  Po-Sheng 《Educational technology research and development : ETR & D》2022,70(3):823-847

A web design course has complex and diverse skills, which may attract students with an interest in technology and art fields to learn to program. It makes a need to have a flexible learning framework to develop all students to learn in a programming course. This study was designed to develop students’ learning achievement and computational thinking (CT) abilities by using a Design Thinking (DT)—Conceive-Design-Implement-Operate (CDIO) engineering design framework in a flipped web programming course. The participants were 41 students (males?=?17, females?=?24) coming from a Taiwan University. All of the students (20–21 years old) had e-learning-related backgrounds in a teacher’s college. The experiment was conducted for 14 weeks. The flipped learning and flipped DT-CDIO course each had a total teaching time of 6 weeks, and the midterm exam and final exam each took one week. We used a questionnaire and formative assessment to examine the students’ computational thinking ability and learning achievement before and after the course was applied. The results showed the students significantly improved their learning achievement and computational thinking ability. There were no significant gender differences in learning achievement. Some gender differences could be seen in some dimensions of CT ability. This study shows that the DT-CDIO framework brings many benefits to promote interdisciplinary learning by attracting STEAM talent and providing evidence to support the importance of flipped web programming courses.

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