高强度间歇训练的科学与实践:应用考量与关键指标

高强度间歇训练(HIIT)是以≥无氧阈或最大乳酸稳态的负荷强度进行多次持续时间为几秒到几分钟的练习,并且每 2.次练习之间安排不足以使练习者完全恢复的静息或低强度练习的训练方法。进入2 1.世纪以来,HIIT受到了训练科学与实践领域的密切关注,越来越多的教练员在训练实践中开始采用HIIT来提升运动员的竞技表现。然而,HIIT不只是“高强度”和“间歇”这么简单,其效果和价值的发挥需要考虑诸多因素。本文基于《高强度间歇训练的科学与应用:训练安排的解决方案》一书内容,分别从形式和目标类型、应用的整体框架、应用情境、同期化训练、关键指标 5.个方面对HIIT进行了论述,旨在为教练员和科研人员在训练实践当中应用HIIT并发挥HIIT的价值提供参考     

Energy turnover during 24 hours and 6 days of adventure racing

Abstract

Energy turnover was assessed in two conditions of mixed ultra-endurance exercise. In Study 1, energy expenditure and intake were measured in nine males in a laboratory over 24 h. In Study 2, energy expenditure was assessed in six males during an 800-km Adventure race (mean race time 152.5 h). Individual correlations between heart rate and oxygen uptake ([Vdot]O₂) were established during pre-tests when kayaking, cycling, and running. During exercise, energy expenditure was estimated from continuous heart rate recordings. Heart rate and [Vdot]O₂ were measured regularly during fixed cycling work rates to correct energy expenditure for drift in oxygen pulse. Mean energy expenditure was 18,050 ± 2,390 kcal (750 ± 100 kcal · h^?1) and 80,000 ± 18,000 kcal (500 ± 100 kcal · h^?1) in Study 1 and Study 2 respectively, which is higher than previously reported. Energy intake in Study 1 was 8,450 ± 1,160 kcal, resulting in an energy deficit of 9,590 ± 770 kcal. Body mass decreased in Study 1 (?2.3 ± 0.8 kg) but was unchanged in Study 2. Fat mass decreased in Study 2 (?2.3 ± 1.5 kg). In Study 1, muscle glycogen content decreased by only 60%. Adventure racing requires a high energy expenditure, with large inter-individual variation. A large energy deficit is caused by inadequate energy intake, possibly due to suppressed appetite and gastrointestinal problems. The oxygen pulse, comparing start to 12 h of exercise and beyond, increased by 10% and 5% in Study 1 and Study 2 respectively. Hence, estimations of energy expenditure from heart rate recordings should be corrected according to this drift.     

The impact of L1 writing system on ESL knowledge of vowel and consonant spellings

Orthographic knowledge, the general ability to learn, store, and use information about the orthographic form of words (Stanovich & West, 1989), is a crucial skill for supporting literacy. Although the development of first language (L1) orthographic awareness is impacted by the characteristics of a learner’s L1 writing system, relatively little is known about what impact the L1 may have on second language (L2) orthographic awareness. In this study, English language learners from three L1s (French, Hebrew, Mandarin Chinese), plus L1 English speakers, were tested on their English spelling knowledge using a word-pseudohomophone discrimination task. In addition to allowing for the cross-linguistic comparisons, items were designed to examine whether learners had differing performance on pseudohomophones (misspellings) that targeted vowels versus consonants. Consistent with previous research (e.g., McBride-Chang, Bialystok, Cong, & Li, 2004), the L1 Chinese speakers had the highest (L2) accuracy, followed by the L1 Hebrew and the L1 French speakers. The participants from non-alphabetic languages (Hebrew and Chinese) had significantly lower accuracy on items with misspellings involving vowels compared to consonants, and the size of the vowel-consonant accuracy difference varied substantially across L1 groups. The results demonstrate that the characteristics of a learner’s L1 writing system, particularly the existence of vowel and consonant graphemes, impact the development of L2 orthographic knowledge and sensitivity to different types of word misspellings.     

Exploring the potential impact of reciprocal peer tutoring on higher education students’ metacognitive knowledge and regulation

It is widely recognized that metacognition is an important mediator for successful and high-level learning, especially in higher education. Nevertheless, a majority of higher education students possess insufficient metacognitive knowledge and regulation skills to self-regulate their learning adequately. This study explores the potential of reciprocal peer tutoring to promote both university students’ metacognitive knowledge and their metacognitive regulation skills. The study was conducted in a naturalistic higher education setting, involving 67 students tutoring each other during a complete semester. A multi-method pretest–posttest design was used combining a self-report questionnaire, assessing students’ metacognitive knowledge and their perceived metacognitive skilfulness, with the analysis of think-aloud protocols, revealing students’ actual use of metacognitive strategies. Results indicate no significant pretest to posttest differences in students’ metacognitive knowledge, nor in their perception of metacognitive skill use. In contrast, significant changes are observed in students’ actual metacognitive regulation. At posttest, students demonstrate significantly more frequent and more varied use of metacognitive regulation, especially during the orientation, monitoring, and evaluation phases. Furthermore, our findings point to an increase in more profound and higher-quality strategy use at posttest.     

Openness and innovation—Home and export demand effects on manufacturing innovation: Panel data evidence for Ireland and Switzerland

Recent studies in the tradition of Schmookler have re-emphasised the potential role of demand in stimulating innovation. Here, we reconsider the role of ‘home’ and ‘export’ market demand in stimulating manufacturing innovation using comparable panel data for two small open economies - Ireland and Switzerland. Our analysis is based on the estimation of reduced form innovation production functions using panel data estimators over the sample period 1994-2005. For a range of innovation indicators, however, we find little evidence of any significant market demand effects, with innovation performance instead determined largely by firm-level capability effects and characteristics. In policy and strategy terms this suggests the continued value of measures to improve innovation capability regardless of market demand conditions. In more methodological terms our results suggest the validity of the usual assumption implicit in modelling innovation outputs that supply-side factors predominate.     

The relationship between intelligence and performance on the test of variables of attention (TOVA)

The present study explored the relationship between the intelligence of young adults and their performance on the Test of Variables of Attention (TOVA). The study also examined whether significant differences existed between adults with and without attention-deficit/ hyperactivity disorder (ADHD) on TOVA errors of omission, errors of commission, mean correct response time, and variability, as well as on performance on the freedom from distractibility (FD) factor on the Wechsler Adult Intelligence Scale-Revised (WAIS-R). Seventy-nine adults participated in the study, including 17 with ADHD and 62 college students without ADHD. Pearson product-moment correlations indicated that none of the correlations between Full Scale IQ (FSIQ) and TOVA variables were significant. Analysis of variance results revealed that adults with ADHD made more errors of omission on the TOVA than did controls. Between-group differences were not found on the remaining dependent variables.     

Predictors of Familial Acculturative Stress in Asian American College Students

The authors examined the predictors of familial acculturative stress in 85 Asian American college students. Participants were primarily 1st‐ and 2nd‐generation U.S. citizens. Results showed that perceived acculturative family conflict and family intragroup marginalization were related to higher levels of familial acculturative stress for participants. Family intragroup marginalization accounted for a statistically significant proportion of the variance in familial acculturative stress after all variables were controlled. The findings emphasize the need to recognize culture‐specific stressors of college students. Implications for college counselors are discussed.     

Power and representation: A postcolonial reading of global partnerships and teacher development through North—South study visits

This paper critically analyses the neo‐liberal discourse informing global education policy and practice. We use postcolonial theory to deconstruct the contexts for global educational partnerships, highlighting how issues of power and representation are central to their development and the learning that takes place within them. Teacher development through North—South study visits is one way of challenging teachers’ worldviews, but these are not always effective. We argue that study visit courses, where learning is facilitated by differently knowledgeable others, have the potential to be more effective, but only if the courses are underpinned by postcolonial theory and informed by socio‐cultural pedagogy.