Scoping review on health-related physical fitness in patients with inflammatory bowel disease: Assessment, interventions, and future directions

Table 2 Description and main findings of studies examining cardiorespiratory fitness by objective maximal oxygen uptake or oxygen uptake at peak exercise assessment in patients with inflammatory bowel disease

Ref.	Study design, country	Sample size (n)	Sample features	CD, UC, IBD-U (n)	Female sex, (%)	Age in yr, mean (SD)	Disease activity	Control group	Test protocol	Main findings, mean (SD), or median (IQR)
Ploeger et al[43], 2011	Cross-sectional study, Canada	29	N/A	19, 10, 0	41%	13.7 (2.3)	Remission (n = N/A) or mildly active disease (n = N/A)	Healthy age-matched and sex-matched youth	Incremental ramp cycle ergometer test: Height-based increase of work rate every 2 min until exhaustion (pedaling frequency < 50 rpm)	VO2peak: CD, 34.9 (6.5) mL/kg/min; UC, 37.8 (7.7) mL/kg/min; Total, 36.0 (7.0) mL/kg/min; VO2peak CD, UC, total < VO2peak ref (P < 0.05, P < 0.001)
Nguyen et al[44], 2013	Cross-sectional study, Canada	7	N/A	7, 0, 0	N/A	15.2 (2.3)	Remission (n = 7)	Healthy age-matched and sex-matched CG (n = 7)	Incremental ramp cycle ergometer test: Height-based increase of work rate every 2 min until exhaustion (pedaling frequency < 50 rpm)	VO2peak: CD, 43.1 (6.5) mL/kg/min; CG, 53.5 (4.6) mL/kg/min; VO2peak CD < VO2peak CG (P < 0.01)
Otto et al[45], 2012	Retrospective study, United Kingdom	100	Patients awaiting colorectal surgery	54, 46, 0	N/A	41.1 (14.9)	Active disease requiring surgery (n = 100)	Reference values[105]	Incremental ramp cycle ergometer test (8-12 min): Work rate increments based on prediction quotation and PA until exhaustion (pedaling frequency < 40 rpm)	VO2peak: CD, 20.0 (7.9) mL/kg/min;UC, 21.9 (7.1) mL/kg/min; Total, 20.9 (7.6) mL/kg/min; VO2peak total; VO2peak ref (P < 0.0001)
Vogelaar et al[28], 2015	Cross-sectional study, The Netherlands	20	With fatigue (n = 10), without fatigue (n = 10)	15, 5, 0	50%	37.3 (11.4)	Remission (n = 20)	Reference values[106]	Incremental ramp cycle ergometer test (8-12 min): Work rate starting at 20 W, which increased by 15-20 W/min until exhaustion (pedaling frequency < 60 rpm)	VO2peak: IBD with fatigue, 1.99 (0.44) L/min; IBD without fatigue, 2.43 (0.75) L/min; VO2peak IBD < VO2peak ref (P = N/A)
Tew et al[59], 2019	Pilot RCT, United Kingdom	36	N/A	36, 0, 0	53%	36.9 (11.2)	Remission (n = 32) or mildly active disease (n = 4)	N/A	Incremental ramp cycle ergometer test: Work rate starting at 0 W, which increased by 15-20 W/min until exhaustion (pedaling frequency < 60 rpm)[107]	VO2peak1: CD, 28.2 (8.6) mL/kg/min
Bottoms et al[61], 2019	Secondary analysis of Tew et al[59], United Kingdom	25	HIIT group (n = 12), MICT group (n = 13)	25, 0, 0	60%	N/A for total sample	Remission (n = 32) or mildly active disease (n = 4)	N/A	Incremental ramp cycle ergometer test: Work rate starting at 0 W, which increased by 15-20 W/min until exhaustion (pedaling frequency < 60 rpm)[107]	VO2peak1: N/A for total sample; CD HIIT group, 27.3 (7.7) mL/kg/min; CD MICT group, 28.7 (8.6) mL/kg/min
van Erp et al[57], 2021	Pilot study, The Netherlands	25	With severe fatigue	21, 3, 1	40%	45 (2.6)	Remission (n = 25)	N/A	Incremental ramp cycle ergometer test: Protocol N/A	VO2max1: IBD, 28 (25-31) mL/kg/min

¹Baseline values are shown.

CD: Crohn’s disease; CG: Control group; HIIT: High-intensity interval training; IBD: Inflammatory bowel disease; IBD-U: Inflammatory bowel disease unclassified; IQR: Interquartile range; MICT: Moderate-intensity continuous training; N/A: Not available; PA: Physical activity; RCT: Randomized controlled trial; ref: Reference; SD: Standard deviation; UC: Ulcerative colitis; VO₂max: Maximal oxygen uptake; VO₂peak: Oxygen uptake at peak exercise.