Randomized controlled study on resistive vibration exercise (EVE study): protocol, implementation and feasibility.
(5/14)
OBJECTIVES: A training intervention comparing resistance exercise with or without whole-body vibration (WBV) was conducted to compare acute and chronic effects on functional and molecular parameters. METHODS: A six-week training intervention was performed including 26 healthy males (26 years, SD=4). Two groups were analyzed in a parallel design performing either resistive exercise (RE, n=13) or resistive vibration exercise (RVE, n=13) training with weekly increasing vibration frequencies (20-40Hz). Resting and exercising blood pressure and heart rate were measured before and after the 6-week intervention. RESULTS: Both training interventions decreased resting systolic blood pressure (P=0.003). Resting diastolic blood pressure was significantly decreased only in the RVE group (P=0.01). Exercising diastolic blood pressure was significantly decreased during the final training (P<0.001) with no additional effect of superimposed vibrations. Resistance exercise with superimposed vibrations evoked back pain to a higher degree than resistance exercise alone when training at frequencies above 30Hz (P<0.01). CONCLUSIONS: These data suggest positive effects of resistance exercise upon cardiovascular health and vascular responsiveness and a further beneficial effect of superimposed vibrations in decreasing resting diastolic blood pressure. Finally, development of back pain may be fostered by superimposed vibrations to high training loads, particularly at higher frequencies. (+info)
pQCT-assessed relationships between diaphyseal design and cortical bone mass and density in the tibiae of healthy sedentary and trained men and women.
(6/14)
In a pQCT study of running-trained and untrained men and women we had shown that bone mass distribution along the tibia was adapted to the usage-derived stress pattern. To study the possible association between the efficiency of diaphyseal design and bone material stiffness, we extend the analysis of the same sample to correlate pQCT indicators of the distribution (CSMIs), mass (BMC), and density (vBMD) of cortical bone tissue as descriptors of "distribution/mass" (d/m) or "distribution/quality" (d/q) relationships. The d/m and d/c curves followed positive (exponential) and negative (hyperbolic-like) equations, respectively. Distribution curves of r coefficients throughout the bone were all bell-shaped, reaching a maximum towards the mid-diaphysis. The CSMIs and BMC were higher, and vBMD was lower in men than women and in runners than non-runners. The d/m relationships were described by unique curves for all groups while d/q relationships were better adjusted to separate curves for men and women. Results support that: 1. diaphyseal design reflects the relative influence of bending/torsion stress along the bones, tending to minimize bone mass; 2. there is a trade-off between cortical bone "quality" and distribution; 3. d/m and d/q relationships are related to bone mechanical environment, and 4. d/q relationships are affected by sex. (+info)
Orthostatic intolerance without postural tachycardia: how much dysautonomia?
(7/14)