The effects of in-season high intensity interval training on professional male soccer players' running performances, were investigated. Twenty-two subjects participated in two consecutive training periods of ten weeks. The first period was considered as a control period and was compared with a period where two high intensity interval training exercises were included in the usual training program. Intermittent runs consisted of twelve to fifteen 15-s runs at 120% of maximal aerobic speed alternated with 15-s of rest. Sprint repetitions consisted of twelve to fifteen all-out 40-m runs alternated with 30-s of rest. Results from the high intensity interval training have shown that maximal aerobic speed was improved (+8.1±3.1%; p<0.001) and that the time of the 40-m sprint was decreased (-3.5±1.5%; p<0.001), while no change in either parameters were observed during control period. This study shows that improvements in physical qualities can be made during the in-season period.
This paper provides new empirical evidence on housing bubble timing, volatility spillover, and bubble contagion between Japan and its economic partners, namely, the United States, the Eurozone, and the United Kingdom. First, we apply a generalized sup ADF (GSADF) test to the quarterly price-to-rent ratio from 1970Q1 to 2018Q4 to detect explosive behaviors in housing prices. Second, we analyze the volatility spillover in housing prices between Japan and its economic partners using the multivariate time-varying DCC-GARCH model. Third, we assess bubble contagion by estimating a non-parametric model of bubble migration with time-varying coefficients. We document two historical bubble episodes from 1970 to 2018 in Japan’s housing market. Moreover, we find evidence of volatility spillover effects and bubble contagion between Japan’s real estate market and its most important economic partners during several periods. In this context of market integration, countries need to develop coordinated real estate policies to address the risk of global real estate bubbles.
Using quarterly housing price-to-rent ratios from 1970 to 2018, this paper investigated the presence of real estate bubbles at a national level in eight selected European countries, namely Belgium, France, Germany, Italy, the Netherlands, Portugal, Spain, and the United Kingdom. Then, we analyzed bubbles contagion among these countries. We applied the generalized sup ADF test developed by Phillips et al. (2015) to detect explosive behavior in house prices. Subsequently, we implemented the non-parametric model with time varying coefficients developed by Greenaway-McGrevy and Phillips (2016) to estimate bubbles contagion among European real estate markets. We found evidence of at least one historical bubble in all these countries, with Germany, the Netherlands, Portugal, and Spain currently experiencing a rising bubble. The results also suggest that bubbles are contagious between these real estate markets.
Over the last decade, the use of foodstuffs such as corn, wheat and soybean in biofuels production has been growing sharply in the United States, Canada and Europe. This growth has increased total demand for agricultural commodities and stimulated agricultural prices. However, corn, rice, wheat and soybean are the most important sources of calorific energy for West African Economic and Monetary Union (WAEMU) member states' population, and WAEMU countries are highly dependent on the imports of these products. Consequently, rising prices can have an important impact on imports and severe consequences on food security in these developing countries. This paper aims to investigate: (i) the short-term and long-term relationships between the prices of corn, rice, wheat, soybean and oil and their volatilities, and (ii) the effects of these agricultural commodities prices shocks on the imports of each WAEMU member states. The Autoregressive Distributed Lag (ARDL) model, the Multivariate Generalized Autoregressive Conditional Heteroskedasticity (MGARCH) model and the Granger causality test are used in this investigation. The results show that imports of agricultural commodities in WAEMU countries are highly and significantly sensitive to price changes in international market. In short term as well as in long term, there is a significant relationship between the prices of these products. We find a positive relationship in general between prices volatilities, and negative effects of price volatility on imports. Thus, distortions in world agricultural markets threaten considerably food security in WAEMU countries, especially access to food for vulnerable and low-income populations. Policy makers must adopt viable strategies to increase agricultural production and limit their dependence on imports.
This paper investigates the presence of speculative bubbles in the Scandinavian countries namely Denmark, Finland, Norway, and Sweden over the period from 1980Q1 to 2018Q4 and searches for evidence of bubble migration among those countries. First, we apply the GSADF test developed by Phillips et al. (2015) on quarterly housing price-to-rent ratios to test for exuberance and episodic bubbles. Subsequently, we examine bubble migration between these markets using the non-parametric model with time-varying coefficients (NPM-TVC) developed by Greenaway-McGrevy and Phillips (2016). We find evidence of episodic bubbles in all the Scandinavian real estate markets for the period 1980 to 2018. Our results also indicate that housing bubbles are contagious between these markets during several periods, and the market connection is stronger for geographically neighboring countries.
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