title: Interval and continuous exercise enhances aerobic capacity and hemodynamic function in CHF rats.
abstract: OBJECTIVE
  The aim of the present study was to compare the effects of continuous versus interval aerobic exercise training on hemodynamic parameters, cardiac remodeling, and maximal exercise capacity (MEC) in chronic heart failure (CHF) rats.
  
  
  METHODS
  Twenty-four male Wistar rats were subjected to myocardial infarction (MI) surgery. Five weeks post MI, the animals were assigned to one of three groups: sedentary group (CHF-Sed, n=8), aerobic continuous training group (CHF-ACT, n=8), and aerobic interval training group (CHF-AIT, n=8). Treadmill training was performed five times a week for 8 weeks (ACT: 50 min/day at 15 m/min and AIT: 40 min/day with 8 min of warm-up at 10 m/min and exercise at 15 m/min 4×4 min interspersed with 4×4 min at 23 m/min). MEC was evaluated pre and post exercise program.
  
  
  RESULTS
  Left ventricular end-diastolic pressure (LVEDP), left ventricular mass/body mass ratio (LVM:BM), and total collagen volume fraction were lower in the trained groups compared with the sedentary group, but no difference was found between the trained groups. Systolic ventricular pressure (SVP) and maximum positive derivative of LV pressure (+dP/dtmax) were higher in the trained groups, but CHF-ACT showed higher +dP/dt(max) compared to CHF-AIT. Both training regimens were able to increase MEC. However, the aerobic interval training was superior for improving MEC.
  
  
  CONCLUSIONS
  Aerobic training is an important intervention to improve cardiac function and remodeling and physical capacity in CHF rats. Interval training is a potential strategy to maximize the results, but exercise type and intensity are still topics to be explored.
authors.affiliation: Laboratório de Fisiologia, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, BR.
authors.forename: Ramiro B
authors.initials: RB
authors.lastname: Nunes
authors.affiliation: Laboratório de Fisiologia, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, BR.
authors.forename: Jadson P
authors.initials: JP
authors.lastname: Alves
authors.affiliation: Laboratório de Fisiologia, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, BR.
authors.forename: Luíza P
authors.initials: LP
authors.lastname: Kessler
authors.affiliation: Laboratório de Fisiologia, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, BR.
authors.forename: André Z
authors.initials: AZ
authors.lastname: Dornelles
authors.affiliation: Laboratório de Fisiologia, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, BR.
authors.forename: Giuseppe P
authors.initials: GP
authors.lastname: Stefani
authors.affiliation: Laboratório de Fisiologia, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, BR.
authors.forename: Pedro D
authors.initials: PD
authors.lastname: Lago
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000502:physiology*; D005080:Exercise Test; D005081:Exercise Therapy / Q000379:methods*; D006321:Heart / Q000502:physiology*; D006333:Heart Failure / Q000503:physiopathology*; D006439:Hemodynamics / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar