Table 2.

Schedule of events for all groups

Study procedure	Screen/baseline period		Intervention period					Follow-up
	Screen visit 1	Baseline visit 2	Visits 3–6b	Visits 7–10b	Visits 11–14b	Visits 15–18b	Visits 19–22b	Visit 23a	Visit 24a	Non-visit surveys
Day (window, ± days)	−21 to −1	−21 to −1	1 − 14	15 − 28	29 − 42	43 − 56	57 − 70	71 ± 4	154 ± 7	Once every 4 weeksc
Screening/baseline:
Informed consent	X
Inclusion/exclusion	X
Medical history	X
Weight	X							X	X
Height and demographics	X
PAR-Q, IPAQ	X
Electrocardiogram	X
Sorensen test	X
Randomization			X
Exercise sessions:
Exercised			X	X	Xd	X	X
Efficacy:
MRI		X						X	X
DEXA		X						X	X
Strength		X						X	X
Endurance		X						X	X
Pain and disability	X	X	X	X	X	X	X	X	X	X
Treatment acceptability			X	X	X	X	X

^aEfficacy outcome measures may be collected in more than one visit if needed and/or preferred. ^bExercise training sessions will be performed twice per week with at least 1 day between the exercise sessions. Once every 2 weeks, prior to performing the exercise, the pain, disability, and treatment acceptability outcomes will be assessed (i.e., pain, disability, and treatment acceptability will be quantified on visits 6, 10, 14, 18, and 22). ^cOn days 98, 126, 154, 182, 210, 238, 266, 294, and 322 ± 3 days study participants will be contacted via email to log onto a secure web-based survey system where they will be asked to rate their perceived disability (Roland Morris Disability Questionnaire) and back pain (0 − 10 numerical pain rating scale) over the past 7 days. ^dOne of the exercise training sessions will be replaced by the strength assessment sessions during week 5.

DEXA dual-energy X-ray absorptiometry, IPAQ International Physical Activity Questionnaire, MRI magnetic resonance imaging, PAR-Q Physical Activity Readiness Questionnaire