The ball in play demands of international rugby union

Objectives: Rugby union is a high intensity intermittent sport, typically analysed via set time periods or rolling average methods. This study reports the demands of international rugby union via global positioning system (GPS) metrics expressed as mean ball in play (BiP), maximum BiP (max BiP), and whole match outputs. Design: Single cohort cross sectional study involving 22 international players, categorised as forwards and backs. Methods: A total of 88 GPS files from eight international test matches were collected during 2016. An Opta sportscode timeline was integrated into the GPS software to split the data into BiP periods. Metres per min (m.min-1), high metabolic load per min (HML), accelerations per min (Acc), high speed running per min (HSR), and collisions per min (Coll) were expressed relative to BiP periods and over the whole match (>60min). Results: Whole match metrics were significantly lower than all BiP metrics (p < 0.001). Mean and max BiP HML, (p < 0.01) and HSR (p < 0.05) were significantly higher for backs versus forwards, whereas Coll were significantly higher for forwards (p < 0.001). In plays lasting 61s or greater, max BiP m.min-1 were higher for backs. Max BiP m.min-1, HML, HSR and Coll were all time dependant (p < 0.05) showing that both movement metrics and collision demands differ as length of play continues. Conclusions: This study uses a novel method of accurately assessing the BiP demands of rugby union. It also reports typical and maximal demands of international rugby union that can be used by practitioners and scientists to target training of worst-case scenario's equivalent to international intensity. Backs covered greater distances at higher speeds and demonstrated higher HML, in general play as well as 'worst case scenarios'; conversely forwards perform a higher number of collisions

Role of creatine supplementation on exercise-induced cardiovascular function and oxidative stress

Many degenerative diseases are associated with increased oxidative stress. Creatine has the potential to act as an indirect and direct antioxidant; however, limited data exist to evaluate the antioxidant capabilities of creatine supplementation within in vivo human systems. This study aimed to investigate the effects of oral creatine supplementation on markers of oxidative stress and antioxidant defenses following exhaustive cycling exercise. Following preliminary testing and two additional familiarization sessions, 18 active males repeated two exhaustive incremental cycling trials (T1 and T2) separated by exactly 7 days. The subjects were assigned, in a double-blind manner, to receive either 20 g of creatine (Cr) or a placebo (P) for the 5 days preceding T2. Breath-by-breath respiratory data and heart rate were continually recorded throughout the exercise protocol and blood samples were obtained at rest (preexercise), at the end of exercise (postexercise), and the day following exercise (post24 h). Serum hypdroperoxide concentrations were elevated at postexercise by 17 ± 5% above preexercise values (p = 0.030). However, supplementation did not influence lipid peroxidation (serum hypdroperoxide concentrations), resistance of low density lipoprotein to oxidative stress (t1/2max LDL oxidation) and plasma concentrations of non-enzymatic antioxidants (retinol, α-carotene, β-carotene, α-tocopherol, γ-tocopherol, lycopene and vitamin C). Heart rate and oxygen uptake responses to exercise were not affected by supplementation. These findings suggest that short-term creatine supplementation does not enhance non-enzymatic antioxidant defence or protect against lipid peroxidation induced by exhaustive cycling in healthy males

Making connections: Social networks in international business

Insights from social network research have generated significant advancements in disciplines such as sociology, economics, and psychology. In comparison, the incorporation of social network ideas into international business (IB) research remains more limited. The purpose of this special issue is to foster further research on social networks in IB. In our introductory essay, we provide a brief overview of network research in the IB domain to give a sense of some of the major ongoing themes and to illustrate how the social network approach can provide fresh insights and add substantive value to the field. To emphasize the considerable potential of using social network theories and ideas to advance research and understanding in IB, we also indicate some future directions. We follow these with a summary of the five articles in the special issue