The effects of HIIT appear to be comparable to those of continuous exercise in relation to functional and cardiovascular responses .
OBJECTIVE To evaluate the effects of high-intensity interval training ( HIIT ) , in comparison with those of continuous exercise , on functional capacity and cardiovascular variables in patients with COPD , through a systematic review and meta- analysis of r and omized controlled trials .
Improvement of heart rate variability after exercise training and its predictors in COPD.
BACKGROUND Current literature lacks solid evidence on the improvement of heart rate variability ( HRV ) after exercise training in patients with COPD . OBJECTIVES We aim ed to investigate changes in HRV after two exercise training programs in patients with COPD and to investigate the determinants of these eventual changes . METHODS Forty patients with COPD ( FEV(1 ) 39 ± 13%pred ) were r and omized into high ( n = 20 ) or low ( n = 20 ) intensity exercise training ( 3-month duration ) , and had their HRV assessed by the head-up tilt test before and after either protocol s. Baseline spirometry , level of daily physical activity , exercise capacity , body composition , functional status , health-related quality of life and muscle force were also assessed to investigate the determinants of improvement in HRV after the training program . RESULTS There was a significant improvement in HRV only after the high-intensity protocol ( pre versus post ; SDNN 29 ± 15 ms versus 36 ± 19 ms ; rMSSD 22 ± 14 ms versus 28 ± 22 ms ; p < 0.05 for both ) . Higher values of biceps brachialis strength , time spent walking in daily life and SDNN at baseline were determinants of improvement in HRV after the training program . CONCLUSIONS High-intensity exercise training  improves HRV at rest and during orthostatic stimulus in patients with COPD . Better baseline total HRV , muscle force and daily physical activity level are predictors of HRV improvements after the training program
The effects of HIIT appear to be comparable to those of continuous exercise in relation to functional and cardiovascular responses .
OBJECTIVE To evaluate the effects of high-intensity interval training ( HIIT ) , in comparison with those of continuous exercise , on functional capacity and cardiovascular variables in patients with COPD , through a systematic review and meta- analysis of r and omized controlled trials .