INTRODUCTION: In cross country skiing, cycling and whole Vibration (vib) are exercised to enhance endurance and strength. In order to have both effects we developed a vib-cycle prototype in which only the bottom crank is fixed on a vib. platform (Patent No.: DE 102004063495). The frame is physically disconnected from any vib Stimulus reducing the shock waves to the lower body's muscles referring to as local vib. The aim of the study was to evaluate whether dynamic vib Stimulus increases oxygen uptake (V"O2). METHOD: The subjects performed an incremental test protocol (Begin: 100Watt, increase 50W/5min) on the vib-cycle at 70 RPM on two occasions, with vib (4mm/20Hz) and without vib (non-vib). They were asked not to exercise for at least 72 hours between the two trials. Power was measured using SRM Powermeter Crank. VO2 was measured with a ZAN 600USB spirograph, The data was averaged every 30 seconds. RESULTS: Greater absolute and relative VO2 values were found during Vibration trial. Statistical significance was detected at 100 (p<0,05), 250 (p<0.05) and 300 Watt (p<0.001) for absolute VO2 and at 250 (p<0.05) and 300 Watt (p<0.05) for relative VO2 (see Fig 1). DISCUSSION: The presented data showed a significant increase in relative and absolute VO2 during vib trial vs non-vib, especially at higher workloads of 250-300 Watt. It may be suggested that vib causes excitation of afferent nerve endings and recruits more receptors which, in turn, activate a larger amount of a-motoneurons leading previous inactive muscle fibres to contraction {Bishop 1974, Person/Koshima 1992). Also, exhausted muscle fibres may be additionally reactivated through vib Stimulus (MESTER et al. 2001). As a result, a larger number of additional motor units will be involved leading to greater amount of consumed 02, especially during higher workload. CONCLUSION: The results show specific respiratory effects to local vib during cycling, mainly in an increase in VO2 at higher workloads of 250 and 300 Watt. This "breaking point" in intensity seems to be favourable for enhancing gas exchange mainly due to the additional activation of motor units without nameable changes in muscle energy pathways. From a respiratory point of view, the data reveals and underlines the necessity to perform higher workloads in order to activate inert muscle fibres which would not be triggered during common road- or ergometer cycling. In the future this type of additional muscle Stimulus might be favourable to enhance strength and endurance performance.
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