A COMPARISON OF AMBULATORY OXYGEN CONSUMPTION DURING CIRCUIT WEIGHT TRAINING AND DURING AEROBIC EXERCISE IN PATIENTS WITH CHRONIC HEART FAILURE (CHF)
D.J. Green*, K. Watts, A.J. Maiorana, J.G. O'Driscoll.
Cardiac Transplant Unit, Royal Perth Hospital, and Department of Human Movement, The University of Western Australia, Western Australia.
Background: the present study compared the oxygen demand (VO2) associated with a typical circuit weight training (CWT) exercise session to that during continuous aerobic exercise in patients with CHF.
Methods: Initially, peak oxygen consumption (VO2peak) and muscular strength (1RM) were assessed in six CHF patients (62±7 years) recruited from the Cardiac transplant Unit at Royal Perth Hospital. Each subject was studied during two types of exercise; continuous cycling on a bicycle ergometer at 70-80% of peak HR (aerobic condition) and CWT (50-60% of maximal voluntary contraction) performed with an active recovery on a bicycle ergometer at 70-80% of peak HR (CWT condition).
Results: the two forms of exercise were of similar intensity in terms of VO2, rate of perceived exertion (RPE) and HR responses. In addition, exercise modality did not influence haemodynamic responses (rate pressure product, SBP, DBP, MAP). Minute ventilation (VE) and tidal volume (Tv) were consistently higher and respiratory frequency (RF) lower, during CWT, indicative of a breathing pattern which optimises gas exchange. Results also indicated that, during CWT, RPE significantly correlated with VO2, whereas HR did not. Conversely, during the aerobic exercise, HR correlated with VO2, but no relationship was evident for RPE.
Conclusions: It is concluded that CWT is a beneficial and well tolerated form of exercise training for CHF patients. The results suggest that RPE may be better to prescribe and monitor exercise intensity during CWT, with HR the preferred measure of intensity during aerobic exercise.
