Eat well to get well

Improvement in functional performance is considered an important management goal in patients with chronic obstructive pulmonary disease (COPD). Pulmonary rehabilitation is now considered as an evidence based intervention to achieve an improvement in functional capacity as well as other management goals such as improved health status and reduction in breathlessness.¹ Although exercise training is considered the core component of every pulmonary rehabilitation programme, the optimal method of exercise training as well as the optimal training intensity remains a matter of debate. Standard recommendations for exercise training in healthy subjects are generally transferred to disabled patients with COPD, and the complexity of the disease related changes which make an important contribution to the functional disability experienced is usually ignored.

The metabolic demand of exercise, reflected in the energy expended on activities, is generally overlooked when patients are stressed to increase their activity level. Consideration of energy balance in COPD is important because weight loss and, specifically loss in fat mass, is the result of a negative energy balance. During the last decade most attention has been focused on resting energy expenditure in patients with COPD; in many of these patients hypermetabolism can be demonstrated which is partly related to the level of systemic inflammation.^2,3 However, in normal subjects the energy expenditure for activities is the most variable component of total energy expenditure. While studies in other chronic wasting diseases characterised by hypermetabolism and systemic inflammation—for example, cancer, chronic heart failure, AIDS—have shown an adaptive decrease in activity induced energy expenditure so that total daily energy expenditure is normal, increased activity induced and total daily energy expenditure has been measured in free living ambulatory COPD patients.⁴ Great variations in total energy expenditure, physical activity, …