Table III.

Outcomes of included studies.

Author, year	Outcomes assessed	Conclusions	(Refs.)
Rooyackers	i) Maximal cycle ergometry-4 lpm O2 and room air	Pulmonary rehabilitation improved exercise	(11)
et al, 1997	ii) Constant power cycle ergometry-30% O2 and	performance and quality of life in both
	room air	groups. O2 supplementation during the
	iii) 6MWT-4 lpm O2 and room air	training did not add to the effects of training
	iv) Stair climb-up 4, plateau, down 3	on room air.
	v) Weight lift-lift between racks
	vi) Chronic respiratory Disease Questionnaire
	vii) PFT-Spirometry and transfer coefficient for
	carbon monoxide
Garrod	i) Shuttle walk test	Supplemental O2 during training does little to	(12)
et al, 2000	ii) Chronic respiratory Disease Questionnaire	enhance exercise tolerance although there is a
	iii) Hospital Anxiety and Depression Scale	small benefit in terms of dyspnea. Patients with
	iv) London Chest Activity of Daily Living Scale	severe disabling dyspnea may find symptomatic
		relief with supplemental oxygen.
Wadell	i) 6MWT on 5 lpm O2 and 5 lpm compressed	Supplemental O2 did not further improve the	(13)
et al, 2001	air (random order) with a 1 h rest in between	training effect, compared with training with air,
	ii) Arterial blood gas analysis	in patients with chronic obstructive pulmonary disease.
Emtner	i) Maximal cycle ergometry-30% O2 and	Supplemental O2 provided during high-intensity	(15)
et al, 2003	compressed air	training yields higher training intensity and
	ii) Constant power cycle ergometry-30% O2	evidence of gains in exercise tolerance in
	and compressed air	laboratory testing.
	iii) Chronic respiratory disease questionnaire
	iv) SF-36
	v) PFT-spirometry and lung volume
	vi) Arterial blood gas analysis
Scorsone	i) PFT	O2 supplementation does not contribute to	(24)
et al, 2010	ii) Maximal cycle ergometry	improved exercise performance in patients with
	iii) Constant power cycle ergometry	moderate to severe COPD.
	iv) Arterial blood gas analysis
Spielmanns	i) 6MWT-room air	O2 supplemental oxygen during the training	(26)
et al, 2014	ii) Maximal cycle ergometry-room air	program had no additional benefits in improving
	iii) SF-36	quality of life and exercise capacity in subjects
		with moderate-to-severe COPD.
Alison	i) Endurance shuttle walk test	Both O2 and Air groups significantly improved	(25)
et al, 2019	ii) Incremental shuttle walk test	exercise capacity and health related quality of life
	iii) Chronic Respiratory Disease Questionnaire	with no greater benefit from training with
	iv) Dyspnoea-12 Questionnaire	supplemental O2 than with medical air.

lpm, liter per minute; 6MWT, 6-min walking distance test; SF-36, Medical Outcomes Survey Short Form 36 questionnaire; PFT, Pulmonary Function Test.