The Influence of Preset Frequency, Loading Condition and Exercise Type on the Mechanical Behaviour of a Novel Vibratory Bar.

The influence of preset frequency, loading condition and exercise type on the mechanical behaviour of a novel vibratory bar.

J Strength Cond Res. 2013 Jul 8;
Rodríguez-Jiménez S, Benitez A, García González MA, Moras Feliu G, Maffiuletti NA

This study aimed to analyze the influence of different vibration frequencies, loading conditions and exercise types on the mechanical behaviour of a novel vibratory bar (VB). Fourteen healthy men were asked to hold the VB during lying row (pulling) and bench press (pushing) static exercise as steadily as possible for 10 s with loads of 20, 50 and 80% of their the maximum sustained load (MSL) and at preset vibration frequencies (fin) of 20, 35 and 50 Hz. Root mean square vibration acceleration (aRMS), peak-to-peak displacement (D) and frequency (fout) were gained from a three-dimensional accelerometer fixed to the VB. Increasing vibration frequency (from 20 to 50 Hz) resulted in a progressive and sizeable increase in VB aRMS and fout (both p < 0.001) with smaller variations of D (<5.9%, p < 0.001). Adding weight to the VB (progressive overload from 20 to 80% MSL) did not affect D and minimally altered aRMS (<4.2%, p = 0.014) and fout (<1.7%, p = 0.002). Altering the type of exercise (pulling vs. pushing) did not affect VB aRMS, D and fout. In conclusion, this study establishes the validity of a novel VB and legitimates its use for effective and safe upper-body static exercise with a wide range of vibration frequencies and loading conditions in the context of physical training or rehabilitation. HubMed – rehab


Exercise Habits of Ultramarathon Runners: Baseline Findings from the ULTRA Study.

J Strength Cond Res. 2013 Jul 8;
Hoffman MD, Krishnan E

Little is known about exercise habits of those who compete in foot races longer than the standard 42-km marathon distance. The purpose of this work was to describe the past-year and lifetime exercise patterns of a large cohort of ultramarathon runners. Information on exercise history was collected on 1,345 current and former ultramarathon runners as baseline data for participation in a longitudinal observational study. Median age at the first ultramarathon was 36 years, and the median number of years of regular running prior to the first ultramarathon was 7 (interquartile range 3-15). Age at first ultramarathon did not changed across the past several decades, but there was evidence of an inverse relationship (r=-0.13, p<0.0001) between number of years of regular running prior to the first ultramarathon and calendar year. The active ultramarathon runners (n=1,212) had a prior year median running distance of 3,347 km, which was minimally related to age (r=-0.068, p=0.018), but mostly related to their longest ultramarathon competition of the year (p<0.0001). Running injuries represented the most common reason for discontinuation of regular running, while work and family commitments were reported as the main reasons for not running an ultramarathon in the prior year among those who were regularly running and intending to run ultramarathons again. We conclude that runners tend to be well into adulthood and with several years of running experience before running their first ultramarathon, but 25% have only been regularly running for 3 years or less at the time of their first ultramarathon. HubMed – rehab