Efficacy of abbreviated progressive muscle relaxation training: a quantitative review of behavioral medicine research.

A quantitative review was undertaken of recent research in which abbreviated progressive muscle relaxation training (APRT) was used as an intervention for psychophysiological and stress-related disorders. The strength of association between APRT and outcome measures was calculated for 29 experiments published after 1980. The average effect size across all experiments was moderate (r = .40). Moreover, for experiments that included a follow-up assessment, a similar effect size was noted at the first follow-up (r = .43). Additionally, experiments that used a prospective design (i.e., analyzed change) detected a stronger effect for APRT than those that used a cross-sectional design (i.e., compared groups). APRT was most strongly associated with improvement in experiments that delivered APRT on an individual basis and provided recipients with training tapes. Moreover, the treatment duration and number of sessions positively influenced the strength of association.