Perspective:

This review discusses the clinical application and research supporting the use of exercise training in heart failure (HF). The following are 10 points to remember:

1. Exercise training in HF can improve aerobic capacity (and therefore patient functional capacity) by 15-30%.

2. Exercise capacity is assessed through peak oxygen consumption (pVO₂) measurements obtained during cardiopulmonary stress testing (CPET). pVO₂ is aberrant in HF due to reduced cardiac output and an impaired capacity of the periphery to extract O₂.

3. During maximal exercise, lactate is produced, which leads to CO₂ generation and a compensatory rise in minute ventilation. Ventilatory anaerobic threshold occurs when minute ventilation increases exponentially to VO₂. Exercise training delays the occurrence of anaerobic threshold, which may reduce dyspnea with exertion in HF.

4. CPET protocols that are expected to yield an exercise duration of 8-12 minutes should be selected to ensure that adequate results are obtained. In general, heart failure medications should not be adjusted or held prior to testing.

5. Initial exercise tolerance (pVO₂) measured at the baseline CPET should be used to formulate an exercise prescription (exercise duration and intensity).

6. The 6-minute walk test does not substitute for information obtained from the CPET. Estimating pVO₂ from stress tests that do not measure gas exchange is often erroneous in HF.

7. Muscle wasting is an important contributor to poor functional status in HF. Strength training using resistive exercises should be incorporated into the HF exercise regimen. Strength training has been shown to improve submaximal exercise tolerance and to reduce cardiovascular load by improving muscular efficiency.

8. Exercise training has been shown to reduce natriuretic peptide and catecholamine concentrations as well as markers of oxidative stress, inflammation, and endothelial dysfunction. Exercise training also increases cardiac output—likely due to reduced peripheral afterload rather than improved myocardial contractility.

9. In the largest exercise training trial in HF to date (HF-ACTION), the adjusted composite endpoint of mortality and hospitalization was reduced by 11%.

10. Patient adherence to long-term exercise programs is poor, and training effects wane as little as 2-3 weeks after cessation of exercise.