Article

The purpose of this study was to compare the effects on exertional
dyspnea and exercise capacity of square wave (bilevel) cycle ergometry endurance
exercise training (SWEET)
and comprehensive directed breathing vs. walking while
pushing an OxCar and traditional diaphragmatic breathing for male smokers with
normal spirometry but reduced exercise capacity.
DESIGN: This was a prospective
randomized trial of 24 unmedicated men with exertional dyspnea assigned to SWEET
or OxCar groups. Exertional dyspnea was assessed using the Borg scale during four
tests: incremental exercise, constant exercise at 80% of the peak work rate (PWR)
(maximum tolerated for 3 mins before exhaustion), SWEET, and 6-min walk test.
Both groups trained for 45 mins, 5 days a week, for 6 wks. Before, during, and
after training, 32 lung function parameters were studied at ventilatory anaerobic
threshold, at PWR, and during incremental exercise (30 W/3 mins). RESULTS: For
the SWEET group, exertional dyspnea and the dyspnea index decreased during
incremental exercise, at the ventilatory anaerobic threshold, and at PWR (P <
0.01). At the ventilatory anaerobic threshold, oxygen consumption increased by
74%; minute ventilation, 30%; tidal volume, 91%; and ventilatory efficiency and
oxygen pulse (O(2)P), 25%; and breathing rate (breathing frequency) decreased by
32% (all significant at P < 0.001). At PWR, oxygen consumption increased by 30%;
minute ventilation, 37%; breathing rate, 21%; and ventilatory efficiency and
oxygen pulse, 25% (P < 0.01). During the full incremental test, minute
ventilation, breathing frequency, and heart rate (cardiac frequency) decreased
significantly (P < 0.01). In addition, there was significant improvement (P <
0.001) in SWEET intensity by 63%, constant exercise intensity at 80% of PWR by
38%, and 6-min walk test by 30%. No significant changes were observed for the
OxCar group other than for the 6-min walk test, which increased by 7% (P < 0.05).
CONCLUSIONS: This study suggests that the decline in exercise tolerance for male
smokers can be reduced by intensive exercise training (SWEET) and comprehensive
directed breathing but not by moderate training and traditional diaphragmatic
breathing. Thus, some smokers can be helped despite continuing to smoke.

Langue : ANGLAIS