The Effect Of Muscle Vibration Training on Femoral Artery Blood Velocity And Oxygen Uptake Kinetics

Abstract

Acute and chronic whole body and targeted muscle vibration training has been shown to increase dynamic and isometric strength (Issurin et al, 1994), most likely as a result of altered neuromuscular activation (Bosco et al, 1999). In addition, whole body vibration has been shown to increase popliteal artery blood flow (Kerschan-Schindl et al, 2001) and common femoral artery blood flow (Lythgo et al 2008). PURPOSE: The effect of knee extension exercise with and without super-imposed targeted leg vibration on pulmonary oxygen uptake (VO2 ml-1kg-1min-1) and femoral artery blood velocity (cm/s) was investigated in the present study.: METHODS: Six healthy male subjects participated in this two trial study (age: 21.7 ± 2.3 y; weight: 78.8 ± 7.0 kg; height: 174.5 ± 0.09 cm). Trials were allocated by systematic rotation. Subjects completed 6 sets of 20 repetitions at 25% of their knee extension one repetition maximum (1RM), with 4 min rest between sets. In one of the trials 10 Hz vibration was delivered to the exercising legs via a custom designed device Vibrex (Exoscience Ltd).: RESULTS: Peak force was significantly higher in the vibrated than non-vibrated trials (8.4 ± 1.32% p=0.027), however total work done was not significantly different between trials (81.4 ± 3.2 kJ non-vibration vs 79.9 ± 4.1 kJ vibration trial). Pulmonary oxygen uptake was 12 ± 1% higher in vibration than the non-vibration trials, but this did not reach statistical significance. Heart rate (HR, bpm) was more elevated during exercise and recovery in the vibration vs the non-vibration conditions (5.3 ± 0.99 % and 9.6 ± 1.71 % respectively) but only the recovery HR achieved statistical significance (p=0.016). However, normalised mean peak femoral artery blood velocity tended to be lower in the vibration than the non-vibration trials (3.35 ± 2.73%, nsd).: CONCLUSIONS: The strong tendency for increased pulmonary oxygen uptake during the vibration trials in the absence of any increase in femoral artery mean peak blood velocity could be explained either by vibration-induced improvements in micro-circulation of the quadriceps muscle or altered motor unit recruitment and/or firing patterns. In order to discriminate between these two possible mechanisms, future studies should include muscle oxygenation and EMG data capture.: