There is strong evidence supporting the benefits of regular physical activity in people with heart failure (HF) and all patients should be referred to a specifically designed physical activity program, if available.[#National-Heart-Foundation-of-Australia-and-the-Cardiac-Society-of-Australia] Benefits of exercise training include improved quality of life, cardiorespiratory fitness and reduced symptoms of fatigue and dyspnoea. The gold standard measure of aerobic fitness, peak oxygen consumption (VO2peak), is strongly associated with survival in HF patients and typically increases by 15-20% over a training period of 8-12 weeks, with some studies showing increases of up to 30%.[#myers-j-gullestad-l-vagelos-r-et-al.-1998,#pina-il-apstein-cs-balady-gj-et-al.-2003]
These improvements in cardiovascular fitness are predominantly due to peripheral adaptations, such as improved oxidative capacity of skeletal muscle and enhanced peripheral blood flow following aerobic training, and muscle hypertrophy following resistance training.[#crimi-e-ignarro-l-cacciatore-f-et-al.-2009] Resistance training complements aerobic exercise, resulting in strength increases of up to 40%, although outcomes vary substantially depending on the characteristics of the training intervention.[#volaklis-k-tokmakidis-s.-2005] In 2007, a meta-analysis showed that cardiac dimensions and function could be improved slightly, but only with aerobic exercise rather than resistance exercise.[#haykowsky-m-liang-y-pechter-d-et-al.-2007]
Recent work has raised the possibility that vigorous or high-intensity intermittent exercise may offer superior benefits to HF patients compared with low-to-moderate intensity continuous aerobic training with regard to VO2. This approach should be limited to specialist centres with rapid access to medical support until safety is more definitively established
Psychological benefits of exercise training include reduced depression and anxiety, and improved quality of life.[#oka-rk-de-marco-t-haskell-wl-et-al.-2000,#taylor-rs-sagar-va-davies-ej-et-al.-2014] HF patients who exercise regularly also have better clinical outcomes.[#piepoli-mf-davos-c-francis-dp-et-al.-2004,#smart-n-marwick-th.-2004] The largest exercise training study in HF, the HF-ACTION trial, randomised 2,331 patients to aerobic exercise or usual care. After adjusting for predetermined prognostic factors, exercise training was associated with a 15% reduction in all-cause mortality and decreased the number of hospitalisations due to HF.[#oconnor-c-whellan-d-lee-k-et-al.-2009]
Is exercise safe for patients with heart failure?
To date, research studies have been conducted predominantly in patients with stable symptoms (New York Heart Association [NYHA] Class I-III) and in young males. In these cohorts, moderate-intensity exercise is well tolerated. There are published data on over 125,000 patient-hours of exercise in clinical studies and, to date, there have not been any deaths directly related to the effects of exercise training in any of these studies.[#chen-ym-li-zb-zhu-m-et-al.-2012] Notably, however, exercising patients have fewer episodes of decompensation and other serious events than those who do not exercise.[#chen-ym-li-zb-zhu-m-et-al.-2012]
The safety of exercise for patients with more severe HF, women, the elderly and those recently discharged from hospital is less conclusive; therefore, exercise for these groups should be prescribed more conservatively. Those with more severe symptoms are most likely to demonstrate greater mortality and morbidity benefit from supervised exercise training compared to those with fewer symptoms.[#piepoli-mf-davos-c-francis-dp-et-al.-2004] Similarly, those with frailty also benefit from exercise training and should not be excluded from exercise training programs.