Two new articles from professors James and Karabulut from the COE Department of Health and Human Performance
Below you can read the full references and abstracts of both papers.
Eric G. James, Peter C.M. Molenaar, Karl M. Newell (2011). Time dependence of coupling in frequency-scaled bimanual coordination. Neuroscience Letters, 490, 156-160
Abstract: Prior research has shown that fluctuations in the relative phase of bimanual coordination do not reflect a white Gaussian noise process. The present study furthered the examination of time-dependent properties in bimanual coordination by comparing the magnitude of relative phase variability and the degree of effector independence within the time domain. The original Kelso (1984)  bimanual frequency- scaling protocol was reproduced in which phase transitions from antiphase to in-phase were induced with increasing movement frequency. The results showed that as movement frequency was scaled-up the amount of relative phase variability increased and the effector movements became more dependent prior to the transition. This is consistent with previous modeling showing that stronger effector coupling can prevent the occurrence of phase transitions when long range correlations in relative phase are present. It appears that, as movement frequency is scaled up, increases in effector coupling strength minimize loss of pattern stability and delay the onset of phase transitions.
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Karabulut, M., Bemben, D.A., Sherk, V.D., Anderson, M.A., Abe, T. and Bemben, M.G. (2010). European Journal of Applied Physiology. January 5, 1-9
Abstract: The aim of this study was to examine and compare the effects of different resistance training proto- cols on bone marker concentrations in older men. Thirty- seven healthy older male subjects were assigned to one of three groups: high-intensity resistance training (HI-RT, age = 57.5 ± 0.8); low-intensity resistance training with vascular restriction (LI-VRT, age = 59.9 ± 1.0); and control (CON, age = 57.0 ± 1.1). Blood samples were collected before and after 6 weeks of resistance training to measure the changes in bone formation [bone alkaline phosphatase, (Bone ALP)] and resorption (C-terminal cross-linking telopeptide of Type-I collagen, CTX) marker concentrations. A significant main effect for time was detected in Bone ALP to CTX ratio for the exercise groups (p \ 0.05). There was a significant group effect for percentage changes in serum Bone ALP (21% for LI-VRT, 23% for HI-RT, and 4.7% for CON) and post hoc analysis identified significant increases in serum Bone ALP concentrations in LI-VRT (p = 0.03) and HI-RT (p = 0.02) when compared with CON. The exercise groups had significantly (p \ 0.01) greater strength increases in all upper body and leg exercises compared with CON with no significant differences between the exercise groups except for leg extension strength (HI-RT [ LI-VRT, p \ 0.05). Serum concentrations of Bone ALP and Bone ALP to CTX ratio improved in both resistance training protocols, suggesting increased bone turnover with a balance favoring bone formation. Therefore, despite using low mechanical load, LI-VRT is a potentially effective training alternative to traditional HI-RT for enhancing bone health in older men.
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