Abstract

Varied-intensity work intervals have been shown to induce higher fractions of maximal oxygen uptake during high-intensity interval training compared with constant-intensity work intervals. We assessed whether varied-intensity work intervals combined with intermittent vibration could further increase cyclists' fraction of maximal oxygen uptake to potentially optimise adaptive stimulus. Thirteen cyclists (V over dot O-2max: 69.7 +/- 7.1 ml middot kg(-1) middot min(-1)) underwent a performance assessment and two high-intensity interval training sessions. Both comprised six 5-minute varied-intensity work intervals within which the work rate was alternated between 100 % (3 x 30-second blocks, with or without vibration) and 77 % of maximal aerobic power (always without vibration). Adding vibration to varied-intensity work intervals did not elicit a longer time above ninety percent of maximal oxygen uptake (415 +/- 221 versus 399 +/- 209 seconds, P = 0.69). Heart rate -and perceptual-based training-load metrics were also not affected (all P >= 0.59). When considering individu -al work intervals, no between-condition differences were found (fraction of maximal oxygen uptake, P = 0.34; total oxygen up-take, P = 0.053; mean minute ventilation, P = 0.079; mean heart rate, P = 0.88; blood lactate concentration, P = 0.53; ratings of perceived exertion, P = 0.29). Adding intermittent vibration to varied-intensity work intervals does not increase the fraction of maximal oxygen uptake elicited. Whether intermittent exposure to vibration can enhance cyclists' adaptive stimulus triggered by high-intensity interval training remains to be determined.