Carbohydrate intake and training efficacy – a randomized cross-over study

Carbohydrate (CHO) availability during endurance exercise seems to attenuate exercise-induced perturbations of cellular homeostasis and might consequently diminish the stimulus for training adaptation. Therefore, a negative effect of CHO intake on endurance training efficacy seems plausible. This study aimed to test the influence of carbohydrate intake on the efficacy of an endurance training program on previously untrained healthy adults. A randomized cross-over trial (8-week wash-out period) was conducted in 23 men and women with two 8-week training periods (with vs. without intake of 50g glucose before each training bout). Training intervention consisted of 4x45 min running/walking sessions/week at 70% of heart rate reserve. Exhaustive, ramp-shaped exercise tests with gas exchange measurements were conducted before and after each training period. Outcome measures were maximum oxygen uptake (VO_2max) and ventilatory anaerobic threshold (VT). VO_2max and VT increased after training regardless of CHO intake (VO_2max: Non-CHO 2.6 ± 3.0 ml*min^?1*kg^?1 p = 0.004; CHO 1.4 ± 2.5 ml*min^?1*kg^?1 p = 0.049; VT: Non-CHO 4.2 ± 4.2 ml*min^?1*kg^?1 p < 0.001; CHO 3.0 ± 4.2 ml*min^?1*kg^?1 p = 0.003). The 95% confidence interval (CI) for the difference between conditions was between +0.1 and +2.1 ml*min^?1*kg^?1 for VO_2max and between ?1.2 and +3.1 for VT. It is concluded that carbohydrate intake could potentially impair the efficacy of an endurance training program.     

Effects of inter-limb asymmetries on physical and sports performance: a systematic review

The prevalence of inter-limb asymmetries has been reported in numerous studies across a wide range of sports and physical qualities; however, few have analysed their effects on physical and sports performance. A systematic review of the literature was undertaken using the Medline and SPORT Discus databases, with all articles required to meet a specified criteria based on a quality review. Eighteen articles met the inclusion criteria, relating participant asymmetry scores to physical and sports performance measures. The findings of this systematic review indicate that inter-limb differences in strength may be detrimental to jumping, kicking and cycling performance. When inter-limb asymmetries are quantified during jumping based exercises, they have been primarily used to examine their association with change of direction speed with mixed findings. Inter-limb asymmetries have also been quantified in anthropometry, sprinting, dynamic balance and sport-specific actions, again with inconsistent findings. However, all results have been reported using associative analysis with physical or sport performance metrics with no randomised controlled trials included. Further research is warranted to understand the mechanisms that underpin inter-limb differences and the magnitude of performance changes that can be accounted for by these asymmetries.     

Adapting,correcting and sequencing movements: does working-memory capacity play a role?

Interest in the role of working-memory capacity in everyday abilities has recently extended to the acquisition of motor skills. This review article examines the role of working-memory capacity in two areas of motor skill acquisition: (1) adapting and correcting movements in response to errors, and (2) sequencing movement patterns. Across a number of studies it was evident that individuals with low or underdeveloped working-memory capacity experienced diminished learning when the practice contexts placed high demands on working memory. Verbal working-memory capacity was associated with the ability to correct movement errors, while several studies revealed the importance of spatial abilities, including spatial working-memory capacity, when learning movement adaptations. Visuo-spatial working-memory capacity correlated with movement sequence learning, either explicitly or implicitly, but old age affected this relationship. Despite these correlations, however, our understanding of the relationship between working-memory capacity and motor skill acquisition is clouded by inconsistent results and a reliance on correlational analyses. To extend understanding of the role of working-memory capacity in motor skill acquisition, researchers should seek to explore novel experimental paradigms that bear closer resemblance to everyday tasks.     

Team Shared Cognitive Constructs: A Meta‐Analysis Exploring the Effects of Shared Cognitive Constructs on Team Performance

Sharing similar cognitive structures among team members is one key element for the collective to solve problems and work more efficiently (DeChurch & Mesmer‐Magnus, 2010). Research has shown that team cognition is positively associated with team performance in both organizational and educational settings. Team shared cognition constructs are relatively new constructs and have been identified in the literature as team mental models, shared mental models, information sharing, transactive memory systems, cognitive congruence, and group learning. Cannon‐Bowers and Salas (2001) called for better measures of shared cognition to be developed, partially through the integration of shared cognition measures across disciplines. The purpose of this meta‐analysis is to look at these six team cognition constructs in an effort to help identify which measure, if any, results in predicting team performance best. Results indicated that information sharing was statistically significant compared to team mental memory and group learning, and marginally significant compared to transactive memory systems. Additionally, shared mental models and cognitive congruence showed higher associations with performance compared to team mental models, group learning, and transactive memory systems.     

Virtual Knowledge‐Sharing Communities of Practice at Caterpillar: Success Factors and Barriers

This article reports the results of a qualitative study of success factors and barriers to the development of virtual knowledge‐sharing communities of practice at Caterpillar Inc., a Fortune 100 multinational corporation. The study identified several prerequisites for successful knowledge management through virtual communities of practice: knowledge sharing as a key element of the corporate culture; employees regarding knowledge as a public good belonging to the whole organization, and not as their individual asset; communities self‐organizing around specific performance‐related problems or areas of professional interest of their members; and communities supported by volunteer managers and active core groups of experts. At the same time, the study has identified a number of important barriers to virtual community development. Specifically, even when employees give the highest priority to the interests of the organization, they tend to shy away from contributing knowledge for a variety of other reasons not related to information hoarding. In addition, corporate security considerations and concerns about the accuracy of the information and the potential information overload could clash with the need to promote spontaneous generation of information. Suggestions for overcoming the identified barriers, future research directions, and implications for HRD professionals are formulated.