title: Eccentric exercise in coronary patients: central hemodynamic and metabolic responses.
abstract: OBJECTIVE
  With lengthening (eccentric) muscle contractions, the magnitude of locomotor-muscle mass and strength increase has been demonstrated to be greater compared with shortening (concentric) muscle contractions. In healthy subjects, energy demand and heart rate responses with eccentric exercise are small relative to the amount of muscle force produced. Thus, eccentric exercise may be an attractive alternative to resistance exercise for patients with limited cardiovascular exercise tolerance.
  
  
  METHODS
  We tested the cardiovascular tolerance of eccentric exercise in 13 coronary patients (ages 40-66) with preserved and/or mild reduced left ventricular function. Patients were randomly assigned to either an eccentric (ECC; N = 7) or a concentric (CON; N = 6) training group and trained for 8 wk. Training workload was increased progressively (from week 1 to 5) to an intensity equivalent to 60% [OV0312]O(2peak).
  
  
  RESULTS
  On average, maximum power output achieved with ECC was fourfold compared with CON (357 +/- 96 W vs 97 +/- 21 W; P < 0.005), whereas measures of oxygen uptake and blood lactate were significantly lower (P < 0.05 each), and ratings of perceived exertion were similar for ECC and CON. During a 20-min session of ECC and CON, central hemodynamics was measured by means of right heart catheterization. During ECC, responses of mean arterial blood pressure, systemic vascular resistance, pulmonary capillary pressure, cardiac index, and stroke work of the left ventricle on average were in the normal range of values and similar to those observed during CON. Compared with baseline, after 8 wk of training, echocardiographic left ventricular function was unchanged.
  
  
  CONCLUSIONS
  The results indicate uncoupling of skeletal muscle load and cardiovascular stress during ECC. For low-risk patients with coronary heart disease without angina, inducible ischemia, or left ventricular dysfunction, ECC can be recommended as a safe new approach to perform high-load muscular exercise training with minimal cardiovascular stress.
authors.affiliation: Swiss Cardiovascular Center Bern, Cardiology, University Clinic, University of Bern, Switzerland. katharina.e.meyer@freesurf.ch
authors.forename: Katharina
authors.initials: K
authors.lastname: Meyer
authors.forename: Roger
authors.initials: R
authors.lastname: Steiner
authors.forename: Paul
authors.initials: P
authors.lastname: Lastayo
authors.forename: Kurt
authors.initials: K
authors.lastname: Lippuner
authors.forename: Yves
authors.initials: Y
authors.lastname: Allemann
authors.forename: Franz
authors.initials: F
authors.lastname: Eberli
authors.forename: Jean
authors.initials: J
authors.lastname: Schmid
authors.forename: Hugo
authors.initials: H
authors.lastname: Saner
authors.forename: Hans
authors.initials: H
authors.lastname: Hoppeler
mesh_terms: D000328:Adult; D000368:Aged; D003324:Coronary Artery Disease / Q000534:rehabilitation*; D005081:Exercise Therapy; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000502:physiology; D010101:Oxygen Consumption; D018487:Ventricular Dysfunction, Left; D014891:Weight Lifting
chemical_list: D019344:Lactic Acid