Interventions to increase physical activity (PA) can target this behavior alone or as part of multiple health behavior change (MHBC) interventions. To date, little is known about the content of MHBC interventions compared with single health behavior change (SHBC) interventions. This study sought to compare the number and type of behavior change techniques (BCTs) in SHBC and MHBC interventions using a secondary analysis of studies included in a systematic review of PA interventions in obese populations.