Here is a study which says that - for resistance training aimed at combating low back pain - there is no point in doing more than one set of an exercise. (Incidentally the same as was found in this review - The preponderance of resistance-training studies shows no difference in the gains in muscular strength, hypertrophy, power, or endurance as a result of performing a greater number of sets. )
Randomized trial comparing the effects of one set vs two sets of resistance exercises for outpatients with chronic low back pain and leg pain.
AIM: Progressive resistance exercises (PRE) are prescribed to reverse the deconditioning associated with chronic back pain. The spine rehabilitation program has utilized 2 sets of progressive resistance exercises during each session, with increased resistance between sets, and with successive sessions. Exercise literature has challenged the need for multiple sets of resistance exercises, with a single set producing similar functional benefits. The authors studied whether completing 1 versus 2 sets of resistance exercises would affect strength, pain and disability outcomes in subjects with chronic low back pain (CLBP).
METHODS: The study randomly assigned subjects with CLBP to perform either 1 set or 2 sets of progressive resistance exercises during otherwise identical spine rehabilitation programs. The patient sample included 100 subjects (36 male patients, 64 female patients, mean age 46 years) with chronic back pain referred to spine rehabilitation. Primary outcomes were back strength and progressive isoinertial lifting evaluation (PILE) at discharge. Secondary outcomes were Oswestry disability (0-100) and pain scores (0-10). Exercises consisted of Cybex back extension, rotary torso, pull downs, and multi-hip; lifting of crates from floor-to-waist (lumbar) and waist-to-shoulder (cervical) heights. The maximum levels of exercises were determined using a four repetition to maximum protocol, and the PILE.
RESULTS: At discharge, there was no significant difference in strength, disability or pain measures between subjects completing 1 versus 2 sets of resistance exercises.
CONCLUSION: These findings suggest that there were no added benefits for completing a second set of resistance exercises during therapy sessions for patients with CLBP.