title: Evaluation of maximal exercise performance, fatigue, and depression in athletes with acquired chronic training intolerance.
abstract: OBJECTIVE
  This study compared differences in maximal strength and aerobic capacity and symptoms of fatigue and depression in athletes with acquired training intolerance (ATI) and control athletes (CON) matched for age and current training volume who did not have symptoms of excessive or chronic fatigue associated with their sporting activity.
  
  
  METHODS
  University of Cape Town, Sports Science Institute of South Africa.
  
  
  METHODS
  Twenty ATI and 10 CON athletes participated in the trial. Although the ATI athletes reported symptoms of excessive fatigue during exercise, or symptoms of fatigue that occurred at rest and during activities of daily living, they did not fulfill the criteria for a diagnosis of chronic fatigue syndrome.
  
  
  METHODS
  A training and comprehensive medical history was recorded from all subjects. The Beck Depression Inventory Short Form (BDI-SF) was used to assess levels of depression in both ATI and control subjects. Maximal force output during a 5-second isometric voluntary knee extensor muscle contraction, and maximal aerobic capacity (VO2max), maximal heart rate (HRmax), and maximal blood lactate concentrations during a treadmill running test were measured in all subjects.
  
  
  RESULTS
  There were no differences in maximal isometric force output, peak treadmill running speed, VO2max, HRmax, or blood lactate concentration at rest or after maximal exercise testing between the ATI and CON athletes. However, the BDI-SF scores were higher in the ATI (7.7 +/- 6.6 arbitrary units) than in the CON athletes (1.7 +/- 1.5 arbitrary units; (P = 0.0052).
  
  
  CONCLUSIONS
  These findings suggest that the symptoms of excessive fatigue and acquired training intolerance described by these ATI athletes do not affect their maximal isometric and maximal aerobic capacity, and may be associated with psychologic depression in these athletes.
authors.affiliation: UCT/MRC Research Unit of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa. agibson@sports.uct.ac.za
authors.forename: A
authors.initials: A
authors.lastname: St Clair Gibson
authors.forename: L A
authors.initials: LA
authors.lastname: Grobler
authors.forename: M
authors.initials: M
authors.lastname: Collins
authors.forename: M I
authors.initials: MI
authors.lastname: Lambert
authors.forename: K
authors.initials: K
authors.lastname: Sharwood
authors.forename: E W
authors.initials: EW
authors.lastname: Derman
authors.forename: T D
authors.initials: TD
authors.lastname: Noakes
mesh_terms: D000328:Adult; D002908:Chronic Disease; D003863:Depression; D017079:Exercise Tolerance; D005221:Fatigue / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D018908:Muscle Weakness; D010101:Oxygen Consumption; D013177:Sports