title: The effects of exercise modality on the incidence of plateau at VO2max.
abstract: The purpose of this study was to determine the effect of exercise modality on the incidence of plateau at VO2max. Twelve recreationally active men (age, 21·7 ± 2·3 year; mass, 74·8 ± 6·5 kg; height, 177·6 ± 5·6 cm) completed four incremental tests to volitional exhaustion, of which two were completed on a treadmill (TRE) and two were completed using a cycle ergometer (CYC). The work rate employed for CYC was 1 W·2 s(-1) from an initial loading of 100 W with cadence being maintained at 60 rpm. For TRE, the workload (gradient) increased at a rate of 0·5% · 30 s(-1) while maintaining a constant running speed of 10 kph. Throughout all the trials, VO2 was determined on a breath-by-breath basis using a precalibrated metabolic cart. The criteria adopted for determination of a plateau was a Δ VO2 over the final two consecutive 30-s sampling periods of ≤50 ml · min(-1). Averaging across the two trials per each exercise modality showed a significant difference for plateau incidence between CYC (8%) and TRE (58%) (P = 0·017). This was aligned with a significant difference in the slope of the regression line during the final 60 s of the VO2max test, CYC (99·9 ± 49·7 ml · min(-1)) and TRE (49·6 ± 42·6 ml · min(-1)) (P = 0·017). Repeat measures ANOVA of these data suggests that plateau incidence rates at VO2max differ between treadmill- and cycle ergometry-based exercises. Future studies need to address whether these response rates are replicated in well-trained athletes.
authors.affiliation: Anglia Ruskin University, Cambridge, UK. dan.gordon@anglia.ac.uk
authors.forename: Dan
authors.initials: D
authors.lastname: Gordon
authors.forename: Mashihullah
authors.initials: M
authors.lastname: Mehter
authors.forename: Marie
authors.initials: M
authors.lastname: Gernigon
authors.forename: Oliver
authors.initials: O
authors.lastname: Caddy
authors.forename: Don
authors.initials: D
authors.lastname: Keiller
authors.forename: Richard
authors.initials: R
authors.lastname: Barnes
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001642:Bicycling; D001944:Breath Tests; D015444:Exercise; D005080:Exercise Test / Q000379:methods; D006439:Hemodynamics; D006801:Humans; D016018:Least-Squares Analysis; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000378:metabolism*; D010101:Oxygen Consumption; D011659:Pulmonary Gas Exchange; D011897:Random Allocation; D012420:Running; D013997:Time Factors; D055815:Young Adult