title: Determinants of maximal exercise performance in chronic heart failure.
abstract: BACKGROUND
  Chronic heart failure (CHF) is characterized by symptoms like fatigue, dyspnoea and limited exercise performance. It has been postulated that maximal exercise performance (Wmax) is predominantly limited by skeletal muscle function and less by heart function.
  
  
  OBJECTIVE
  To study the interrelation between most relevant muscle and anthropometrical variables and Wmax in CHF patients in order to develop a model that describes the impact of these variables for maximal exercise performance.
  
  
  METHODS
  In 77 patients with CHF Wmax was assessed by incremental cycle ergometry until exhaustion (20 Watt/3 min). Peak torque (strength) and total work (endurance) for the quadriceps and hamstrings were assessed by isokinetic dynamometry. Isometric strength was measured by hand dynamometry. Relevant muscle areas were calculated by computerized tomography scan.
  
  
  RESULTS
  Significant correlations between Wmax and isokinetic muscle parameters (peak torque and total work) ranged from 0.41-0.65 (P<0.01). Other significant relationships (P<0.01) with Wmax were obtained for age (r=-0.22), gender (r=0.45), fat free mass (FFM) (r=0.51), quadriceps muscle area (r=0.73), hamstrings muscle area (r=0.50), upper leg muscle function (i.e., a combination of muscle strength and muscle endurance) (r=0.71) and isometric strength (r=0.63). Multiple regression analysis showed that upper leg muscle function and quadriceps muscle area could predict 57% of the variance in Wmax.
  
  
  CONCLUSIONS
  Muscle strength and muscle endurance, combined with quadriceps muscle area are the main predictors of maximal exercise performance in patients with CHF.
authors.affiliation: Department of Cardiology, University Medical Centre Utrecht, The Netherlands. P.J.Senden@KNMG.NL
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Senden
authors.forename: Louise W E
authors.initials: LW
authors.lastname: Sabelis
authors.forename: Maria L
authors.initials: ML
authors.lastname: Zonderland
authors.forename: Rik
authors.initials: R
authors.lastname: van de Kolk
authors.forename: Louis
authors.initials: L
authors.lastname: Meiss
authors.forename: Wouter R
authors.initials: WR
authors.lastname: de Vries
authors.forename: Eduard
authors.initials: E
authors.lastname: Bol
authors.forename: Willem L
authors.initials: WL
authors.lastname: Mosterd
mesh_terms: D000273:Adipose Tissue / Q000502:physiology; D000368:Aged; D000886:Anthropometry; D002908:Chronic Disease; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D007866:Leg / Q000502:physiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018482:Muscle, Skeletal / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology; D012737:Sex Factors; D013223:Statistics as Topic; D013318:Stroke Volume / Q000502:physiology