VO₂Kinetics Determined by PRBS Techniques Differentiate Elite Endurance Runners from Elite Sprinters

Abstract

The aim of the study was to examine whether a measure of oxygen uptake (VO2) kinetics could differentiate between 12 elite male endurance (3000-10,000 m) runners and 12 elite male sprint (100-400 m) runners using a pseudo random binary sequence (PRBS) exercise protocol. All exercise tests were performed on an electrically braked cycle ergometer at a constant pedal frequency of 1 Hz. The PRBS exercise intensities alternated between 25 W and 85 W for three consecutive PRBS cycles of 300 s. VO2 was measured breath-by-breath and results were analysed by Fourier techniques in the frequency domain. Blood lactate concentrations taken pre and post testing were below 2 mM. Significantly greater amplitude components were observed in the endurance runners than sprinters at frequencies 6.7 mHz (6.71 +/- 1.09 and 5.47 +/- 0.95 ml x min(-1) x W(-1), respectively) P<0.05 and 10 mHz (4.97 +/- 0.98 and 3.56 +/- 0.69 ml x min(-1) x W(-1) respectively) P<0.01. Phase shift components were significantly shorter in the endurance runners compared to the sprinters at frequency 3.3 mHz (-35.45 +/- 4.31 and -41.26 +/- 5.82 degrees respectively) P<0.05. The results of this study show that VO2 kinetics are differentially faster in elite endurance runners than in elite sprinters. This supports the development of the PRBS technique as a test of sports performance.

Pulmonary O2 uptake on-kinetics in sprint- and endurance-trained athletes

“…The significant difference in the phase II between the SPT and ENT subjects in the present study is in agreement with the earlier results of Edwards et al (1999), who reported that endurance runners had significantly shorter phase shift components in the frequency domain when _ V O 2 kinetics were measured using a PRBS exercise protocol. Similar results have been reported by other groups (Eßfeld et al 1987;Fukuoka et al 1995Fukuoka et al , 1997Edwards et al 2003).…”

“…One population that has not been well studied to date is that of sprint or power-trained athletes. To our knowledge, _ V O 2 kinetics in sprint and power-trained athletes has only been reported in a limited number of studies using sinusoidal (Fukuoka et al 1995(Fukuoka et al , 1997 or pseudorandom binary sequence (PRBS; Edwards et al 1999Edwards et al , 2003 work-rate forcing functions. This lack of information on the _ V O 2 kinetics of sprint and power-trained athletes, particularly in response to ''step'' exercise, is perhaps surprising given that these athletes would be expected to have distinctive muscle metabolic properties (relative both to the general population and to endurancetrained athletes), including a higher proportion of type II fibres in the relevant muscles, a greater muscle phosphocreatine concentration ([PCr]), greater anaerobic enzyme activities, and perhaps a reduced muscle capillary density (Costill et al 1976;Bergh et al 1978;Abernethy et al 1990;Bouchard et al 1992;Ross and Leveritt 2001).…”

Impact of Mental Fatigue on Self-paced Exercise

“…The data acquisition system utilised was a PowerLab 8/35 (AD Instruments, USA). 2 familiarization sessions were subsequently completed for initial trials of the cognitively demanding mental fatigue protocol and also to assess participants' aptitude to self-pace an exercise bout [ 11 ] while cycling at a self-regulated pace corresponding to descriptors from Borg's 6-20 Rating of Perceived Exertion (RPE) scale [ 6 , 7 , 9 ] . Coeffi cient of variation analysis for test-retest reliability of power output (W) across 3 familiarisation bouts (RPE 7 CV = 8 %; RPE 13, CV = 5 %; RPE 18, CV = 4 %) demonstrated the ability of participants to consistently replicate similar performance outcomes when placed in the same condition [ 7 ] .…”

“…information such as muscle soreness, changes in pH or respiratory discomfort [ 25 ] when determining appropriate eff ort in self-paced exercise, but also considers psychological factors such as perceived tiredness [ 11 ] . This supports the previously proposed concept that alterations to the perception of eff ort when mentally fatigued infl uences performance attenuation and the eff ect of brain regulation over exercise performance [ 21 , 25 ] .…”

The Complex Reality of VO2 Kinetics to Steady State: Reassessment of the Models Used to Quantify and Interpret VO2 Kinetics, Steady State, and Time to Steady State

“…Also, a special thank you to the staff members that guided me with teaching over the past three years. Educating has become one of the most rewarding aspects of kinetics over recent years have facilitated the progression of exercise science, sports science, and disease prevention and treatment (Sietsema et al, 1986;Sietsema, 1991;Edwards et al, 1999;Figuira et al, 2008;Grassi et al, 2009;). …”