title: Programming exercise intensity in patients on beta-blocker treatment: the importance of choosing an appropriate method.
abstract: OBJECTIVE
  To verify the usefulness of current recommended level of target exercise heart rate (HR) and of different HR-based methods for calculating target HR in patients with and without beta-blocker treatment.
  
  
  METHODS
  We studied 53 patients not treated with beta-blocker and 159 patients on beta-blocker treatment. All patients underwent a maximal exercise test with gas analysis, and first ventilatory threshold (VT1 or aerobic threshold), second ventilatory threshold (VT2 or anaerobic threshold), time of exercise, maximum load, metabolic parameters, HR at rest (HRrest), HRpeak, HR at VT1 (HRVT1) and at VT2 (HRVT2), and 75, 80, and 85% of HRmax (HR75%, HR80%, HR85%) were calculated. Exercise HR was also determined using the Karvonen formula, applying 60, 70, and 80% of the heart rate reserve (HRR) (HRKarv0.6, HRKarv0.7, and HRKarv0.8).
  
  
  RESULTS
  This study included 102 patients on a beta-blocker and 39 not treated with negative cronotropic effect drugs. Maximum load, metabolic parameters, HRrest, HRpeak, HRVT1, and HRVT2 were significantly lower in patients on beta-blocker treatment. The proportion of patients with a HR75%, HR80%, HR85%, ​​HRKarv0.6, HRKarv0.7, and HRKarv0.8 <VT1 and >VT2 was very high and depended on whether patients were on beta-blocker treatment.
  
  
  CONCLUSIONS
  Prescribed exercise intensity should be within VT1 and VT2, so that the efficacy and safety is guaranteed. If determining VT1 and VT2 is not possible, HR-based methods can be used, but with caution. In fact, there will be always a proportion of patients training below VT1 or above VT2. On the other hand, recommendations for patients on a beta-blocker should be different from patients not receiving a beta-blocker. Patients not treated with a beta-blocker should exercise at HRKarv0.7 or at HR85%. In patients on a beta-blocker, we recommend preferentially a target HR of HRKarv0.6 or HR80%.
authors.affiliation: Rey Juan Carlos University Hospital, Madrid, Spain Infanta Elena University Hospital, Madrid, Spain idiazb@idcsalud.es.
authors.forename: Isabel
authors.initials: I
authors.lastname: Díaz-Buschmann
authors.affiliation: Infanta Elena University Hospital, Madrid, Spain.
authors.forename: Koldo Villelabeitia
authors.initials: KV
authors.lastname: Jaureguizar
authors.affiliation: Rey Juan Carlos University Hospital, Madrid, Spain Infanta Elena University Hospital, Madrid, Spain.
authors.forename: Maria José
authors.initials: MJ
authors.lastname: Calero
authors.affiliation: Rey Juan Carlos University Hospital, Madrid, Spain Infanta Elena University Hospital, Madrid, Spain.
authors.forename: Rosa Sánchez
authors.initials: RS
authors.lastname: Aquino
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D003131:Combined Modality Therapy; D005080:Exercise Test; D005081:Exercise Therapy / Q000379:methods*; D017079:Exercise Tolerance / Q000187:drug effects*; D005260:Female; D006331:Heart Diseases / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D005082:Physical Exertion; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000319:Adrenergic beta-Antagonists
keywords: Beta-blocker; Karvonen’s method; cardiac rehabilitation; exercise intensity; target heart rate