title: The effects of constant vs. variable workload cycling on performance and perception.
abstract: BACKGROUND
  The purpose of this study was to determine whether constant load (CL) cycling or variable load (VL) cycling stimulates different physiological and psychological responses.
  
  
  METHODS
  Recreationally-trained male cyclists (N.=8, age 32±5 yr, weight 75.7±10.9 kg, body fat 13.4±5.6%, VO2peak 4.60±0.62 L/min) completed two experimental trials. During the VL trial, participants alternated between 3 minutes at 45% and 3 minutes at 85% of maximal aerobic power during the 63-minute trial. During the CL trial, participants cycled at a constant 65% of maximal aerobic power for 63 minutes. The total amount of work was held constant for the two trials. Immediately following each trial, participants completed a maximal 10-km performance trial. Blood lactate was measured at 6, 30, and 60 minutes of cycling as well as at the beginning and conclusion of the performance trial.
  
  
  RESULTS
  Time trial performance was not different between VL (16.97±2.07 min) and CL (16.81±1.47 min, P=0.624). There was no difference in VO2 (P=0.429), heart rate (P=0.640), blood lactate (P=0.520), rated perceived exertion (RPE) (P=0.216), Feeling Scale (P=0.626), or attentional focus (P=0.315) between VL and CL 10-km performance time trials. However, RPE (P=0.003) and attentional focus (P=0.016) were elevated in VL.
  
  
  CONCLUSIONS
  These data indicate that VL and CL cycling have no differential effect on subsequent performance or physiology despite differences in perception during the experimental trials.
authors.affiliation: Exercise Physiology Lab, School of Health, Physical Education, and Recreation, University of Nebraska, Omaha, NE, USA - dslivka@unomaha.edu.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Edgerton
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Heesch
authors.forename: Dustin R
authors.initials: DR
authors.lastname: Slivka
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D001288:Attention / Q000502:physiology; D001642:Bicycling / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D008297:Male; D064797:Physical Conditioning, Human / Q000379:methods*; D005082:Physical Exertion / Q000502:physiology