title: Effect of high-intensity submaximal work, with or without rest, on subsequent VO2max.
abstract: OBJECTIVE
  In practice, tests of maximal oxygen uptake (.VO2max) are often preceded by a lactate profile, a highly intense but submaximal exercise bout. The .VO2max response to preceding high-intensity submaximal exercise, with or without a rest period, has not been determined. If .VO2max is limited after a lactate profile, exercise-induced hypoxemia (EIH) may explain the deficit. The purposes of this study were to: 1) examine the effects of high-intensity submaximal exercise, with or without rest, on subsequent .VO2max; and 2) evaluate the role of EIH in causing any observed changes.
  
  
  METHODS
  Ten healthy, well-trained, male cross-country skiers (age = 20.5 +/- 4.7 yr, height = 181.6 +/- 6.0 cm, mass = 72.1 +/- 5.7 kg) completed three exercise trials: an incremental run to fatigue (MAX), MAX preceded by a high-intensity submaximal run (lactate profile) and a 20-min rest period (discontinuous protocol [DC]), and MAX preceded by a high-intensity submaximal exercise run with no rest (continuous protocol [C]). .VO2max, minute ventilation, and arterial oxygen saturation were measured throughout, and diffusion capacity was evaluated 2 min postexercise. RESULTS No significant between trial differences were observed, although the difference between .VO2max determined during the MAX trial (62.7 +/- 6.7 mL.kg-1.min-1) and during the DC trial (58.3 +/- 4.4 mL.kg-1.min-1) approached significance (P = 0.059). DC .VO2max responses could be separated into two groups: five responders whose .VO2max suffered during the DC trial (decreased >7.5% from MAX) and five nonresponders, whose .VO2max was unaffected by preceding submaximal exercise and a rest period. Responders showed greater aerobic capacity during the MAX trial.
  
  
  CONCLUSIONS
  .VO2max is significantly reduced in approximately 50% of cross-country skiers when a maximal exercise test is preceded by high-intensity submaximal exercise and a 20 min rest period; the role of EIH in causing these reductions is unclear.
authors.affiliation: Coaching and Sports Sciences Division, United States Olympic Committee, Lake Placid, NY, USA.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Judelson
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Rundell
authors.forename: Kenneth C
authors.initials: KC
authors.lastname: Beck
authors.forename: Timothy M
authors.initials: TM
authors.lastname: King
authors.forename: Kerry L
authors.initials: KL
authors.lastname: Laclair
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D015444:Exercise / Q000502:physiology*; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D012146:Rest / Q000502:physiology*; D012865:Skiing / Q000502:physiology