Neunhäuserer D, Steidle-Kloc E, Weiss G, Kaiser B, Niederseer D, Hartl S, Tschentscher M, Egger A, Schönfelder M, Lamprecht B, Studnicka M, Niebauer J
Supplemental Oxygen During High-Intensity Exercise Training in Nonhypoxemic Chronic Obstructive Pulmonary Disease
BACKGROUND: Physical exercise training is an evidence-based treatment in chronic
obstructive pulmonary disease, and patients' peak work rate is associated with
reduced chronic obstructive pulmonary disease mortality. We assessed whether
supplemental oxygen during exercise training in nonhypoxemic patients with
chronic obstructive pulmonary disease might lead to superior training outcomes,
including improved peak work rate.
METHODS: This was a randomized, double-blind, controlled, crossover trial.
Twenty-nine patients with chronic obstructive pulmonary disease (aged 63.5 ± 5.9
years; forced expiratory volume in 1 second percent predicted, 46.4 ± 8.6)
completed 2 consecutive 6-week periods of endurance and strength training with
progressive intensity, which was performed 3 times per week with supplemental
oxygen or compressed medical air (flow via nasal cannula: 10 L/min). Each session
of electrocardiography-controlled interval cycling lasted 31 minutes and
consisted of a warm-up, 7 cycles of 1-minute intervals at 70% to 80% of peak work
rate alternating with 2 minutes of active recovery, and final cooldown.
Thereafter, patients completed 8 strength-training exercises of 1 set each with 8
to 15 repetitions to failure. Change in peak work rate was the primary study end
RESULTS: The increase in peak work rate was more than twice as high when patients
exercised with supplemental oxygen compared with medical air (0.16 ± 0.02 W/kg vs
0.07 ± 0.02 W/kg; P < .001), which was consistent with all other secondary study
end points related to exercise capacity. The impact of oxygen on peak work rate
was 39.1% of the overall training effect, whereas it had no influence on strength
gain (P > .1 for all exercises).
CONCLUSIONS: We report that supplemental oxygen in nonhypoxemic chronic
obstructive pulmonary disease doubled the effect of endurance training but had no
effect on strength gain.