How does interval exercise training affect exercise capacity in those patients with cystic fibrosis who cannot undertake standard exercise programmes due to their disease severity?
Why is this important?
There is growing consensus that people with CF may improve exercise capacity, lung function and quality of life through exercise. Exercise capacity, expressed as peak oxygen uptake (VO2peak) has been found to be one of the best predictors of life expectancy in these patients. Those patients with a higher VO2peak related to a value predicted for their age and gender, have a better prognosis than those with a lower VO2peak than predicted.
What did you do?
We investigated the effects of high intensity interval training (IT) using a treadmill. After a full medical examination, this consisted of repetitive short bouts of high intensity exercise, interrupted by short bouts of very low intensity exercise (“active recovery”) or rest. We assessed lung function, power and VO2 at peak performance and submaximal performance for those patients unable to participate in a standard exercise program (SEP). We compared the IT responses with corresponding effects in patients with CF performing a standard exercise programme.
What did you find?
Peak oxygen uptake increased in both groups. However, the standard exercise program effects on VO2 and power were stronger at peak performance whereas IT showed stronger effects at submaximal exercise. Lung function remained unchanged in both groups.
What does this mean and reasons for caution?
In severely affected patients with CF who are unable to participate in standard exercise programs, the present IT program offered an effective and safe alternative strategy to improve exercise capacity. IT improved submaximal exercise capacity to a greater extent than the standard exercise program. The response of peak performance was higher in the standard exercise program. This seems to indicate a specific potential of IT to induce positive peripheral muscular adaptations in spite of diminishing potential of pulmonary response to exercise.
We want to examine if and how modifications of intensity and/or bout duration of IT may enhance exercise capacity, with particular respect to measures of peak performance. Furthermore, we want to examine not only short term but also mid and long-term effects of interval training vs. a standard exercise programme in patients of various levels of functional impairment and severity of disease.