Effects of roller massager on muscle performance, morphology, and oxygenation after exercise-induced muscle damage

This study determined roller massager (RM) effectiveness on ankle plantar flexors’ recovery after exercise-induced muscle damage (EIMD) stimulus. Two experiments were conducted. The first experiment (n=10) examined functional [i.e., ankle plantar flexion maximal voluntary isometric contraction (MVIC) and submaximal (30% of MVIC) sustained force; ankle dorsiflexion maximal range of motion and resistance to stretch; and pain pressure threshold] and morphological [medial gastrocnemius (MG) cross sectional area, thickness, fascicle length, and fascicle angle] variables, before and immediately, 1h, 24h, 48h, and 72 after EIMD. In the second experiment (n=10), changes in MG deoxyhemoglobin concentration kinetics (velocity and amplitude) during a submaximal sustained force test were observed before and 48h after EIMD. Participants performed both experiments twice, with and without (NRM) the application of a RM (6 × 45 seconds with 20 seconds rest between sets). RM intervention did not alter plantar flexors’ strength and flexibility impairment after EIMD, as well the MG morphology and oxygenation kinetics (p>0.05). On the other hand, a strong tendency for an acute (within 1 hour) change of ipsilateral (post-effects: RM=+19%, NRM=-5%, p=0.032) and contralateral (p=0.095) MG pain pressure threshold was observed. In conclusion, the present results suggest that a roller massager has no effect on muscular performance, morphology, and oxygenation recovery after EIMD, except for muscle pain pressure threshold (i.e., a soreness). Thus, RM may have potential application in recovery for people with increased muscle soreness, if performed immediately before a physical task.

Marketing channel behaviour and performance

Thesis submitted to University of Manchester for the degree of Doctor of Philosophy in the Faculty of Business Administration.

The export performance of the 2004 EU enlargement economies since the 1990s : a constant market share analysis

This study focuses the export performance of the 2004 EU enlargement economies between 1990 and 2013. The long time span analysed allows to capture different stages in the relationship of these new members with the EU before and after accession. The study is based on the Constant Market Share methodology of decomposing an ex-post country’s export performance into different effects. Two different Constant Market Share Analysis (CMSA) were selected in order to disentangle, for the exports of the new members to the EU15, (i) the growth rate of exports and (ii) the growth rate of exports relatively to the world. Both approaches are applied to manufactured products first without disaggregating results by sectors and then grouping all products into two different classification of sectors: one considering the technological intensity of manufactured exports and another evaluating the specialization factors of the products exported. Results provide information not only on the ten economies’ export performance as a group but also individually considered and on the importance of each EU15 destination market to the export performance of these countries.