title: Time course of physical reconditioning during exercise rehabilitation late after heart transplantation.
abstract: BACKGROUND
  Exercise rehabilitation improves physical capacity in heart transplant recipients. The time course of physical reconditioning and skeletal muscle adaptation late after transplantation are unknown.
  
  
  METHODS
  Twenty-one heart transplant recipients, at 5.2 +/- 2.1 years after transplantation, completed 1 year of an individually tailored home ergometer-training program (2.1 +/- 0.7 sessions weekly with matched heart rates, intensity at 10% below anaerobic threshold). We analyzed time course of physical reconditioning data for each home-training session (n = 2,396). Constant-load tests with consistent blood lactate concentrations were performed quarterly (n = 105) to estimate the time course of skeletal muscle adaptation. Nine heart transplant recipients served as a control group (CG).
  
  
  RESULTS
  After 12 months, exercise capacity for matched heart rates (112 +/- 11 beats/min; CG, 114 +/- 8 beats/min) increased by 35% +/- 19% (from 43 +/- 14 to 58 +/- 18 W; p < 0.001; CG, 53 +/- 18 to 54 +/- 18 W); 24% of the increase was caused by improved skeletal muscle function and 11% by central functioning. Physical reconditioning showed its greatest increase within the first 3 months (+18%; p < 0.001); 50% of the increase consisted of better skeletal muscle or central functioning. Between the 4(th) and 12(th) months, exercise capacity increased continuously (+15%; p < 0.001), mainly because of better skeletal muscle functioning.
  
  
  CONCLUSIONS
  The persistent improvement in exercise capacity along with consistent lactate concentrations during 12 months of training indicates that exercise training could counteract the negative side effects of immunosuppressive treatment on skeletal muscles. Even late after heart transplantation, physical training should be performed regularly to prevent the accelerated decrease in exercise capacity and in skeletal muscle function.
authors.affiliation: Department for Sports Medicine, Leipzig, Germany. tegtbur.uwe@mh-hannover.de
authors.forename: Uwe
authors.initials: U
authors.lastname: Tegtbur
authors.forename: Martin W
authors.initials: MW
authors.lastname: Busse
authors.forename: Karsten
authors.initials: K
authors.lastname: Jung
authors.forename: Klaus
authors.initials: K
authors.lastname: Pethig
authors.forename: Axel
authors.initials: A
authors.lastname: Haverich
mesh_terms: D000222:Adaptation, Physiological; D000368:Aged; D005081:Exercise Therapy; D005260:Female; D016027:Heart Transplantation / Q000534:rehabilitation*; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D010101:Oxygen Consumption; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D019344:Lactic Acid