Energy cost of different skating techniques in cross-country skiing

The aims of this study were to compare the aerobic energy cost of four 'on-snow' skating techniques in cross-country skiing and to examine the relationships between performance and aerobic energy cost. Twelve male skiers from recreational to national standard performed four level skating trials of 6 min duration in random order, each at the same submaximal velocity but with a different skating technique: (1) 'offset' (V1), using a double asymmetrical and asynchronous pole plant as weight is transferred to one ski; (2) 'two-skate' (V2A), where the pole plant is symmetrical; (3) 'one-skate' (V2), where there is a pole plant as weight is transferred to each ski; and (4) 'conventional', without poles. Oxygen uptake (VO2), pulmonary ventilation, the respiratory exchange ratio and heart rate were measured using a K4(b2) portable gas analyser. The aerobic energy cost (VO2/mean speed) and heart rate were higher (P < 0.05) in the one-skate than in the offset condition. This may be explained by the greater and more efficient use of the upper body and the lower variation in centre of gravity velocity in the offset condition. The aerobic energy cost was 5-9% higher (P < 0.01) in the conventional than in the other techniques, probably because of the shorter duration of propulsive forces within a cycle in the conventional skating condition. Moreover, in ski skating, the mechanical efficiency (propulsive forces/total forces) was shown to be higher in the upper than in the lower limbs. The correlation coefficient between performance and aerobic energy cost was significant in the two-skate (r = 0.68, P = 0.02), one-skate (r = 0.72, P = 0.01) and conventional (r = 0.62, P = 0.04) conditions, but not in the offset condition (r = 0.50, P = 0.10). Our results stress the importance of the upper body component in cross-country skiing and that the aerobic energy cost discriminates between skiers of different standards.     

#MeToo,sexual harassment: an article,a forum,and a dream for the future

#MeToo has breathed new life into the women’s movement and especially into understanding and rectifying sexual harassment, abuse and assault. It has galvanized activists around the globe. And it has placed thousands of stories of the harassed in full view of the public. Sexual harassment, abuse and assault may occur within the organizational context or beyond; but sexual harassment, in particular has been legally labeled an organizational phenomenon. With this in mind, Robin Clair frames the early part of this article around the most recent organizational communication theories (see the appendix for an overview of these theories). Following the essay is a forum, in which invited scholars address questions related to the #MeToo movement.     

Theoretical Frameworks of Performance‐Based Models

The purpose of this article is to highlight theories that support the functions of performance‐based design models and to discuss the implications of integrating divergent models into the system‐oriented human performance technology (HPT) and performance improvement (PI) disciplines. HPT, PI, and instructional systems design (ISD) share a systems framework, along with the influence of common theories such as performance theory, learning theory, adult learning, cognitive psychology, and behavioral psychology (Foshay, Villachica, & Stepich, 2014). This article focuses on the role of theory as a tool in the practitioner's toolbox and as a connection point when working with teams and organizations that have different theoretical orientations. Performance‐based ISD models are discussed, including Robinson and Robinson's (1989) Training for Impact, Brethower and Smalley's (1998) Performance‐Based Instruction, and Bradford and Boler's (2015) Horizon Model. Allen and Sites's (2012) successive approximation model (SAM) retains elements of ADDIE as a process, but the model is iterative rather than systematic in design.