Purpose:
Complex training (CT) involves the coupling of two exercises ostensibly to enhance the effect of the second exercise. Typically, the first exercise is a strength exercise and the second exercise is a power exercise involving similar muscles. In most cases, CT is designed to enhance power. The purpose of this study was twofold. First, this study was designed to determine if lower body power could be enhanced using complex training protocols. Second, this study investigated whether the inclusion of a power exercise instead of a strength exercise as the first exercise in CT would produce differences in lower body power.

Methods:
Thirty-six recreationally-trained men and women aged 20 to 29 years attending a college physical education course were randomly assigned to one of three groups: squat and countermovement squat jumps (SSJ), kettlebell swings and countermovement squat jumps (KSJ), and a control (CON). Training involving CT lasted 6 weeks. All participants were pre- and posttested for vertical jump performance in order to assess lower body power.

Results:
Vertical jump scores improved for all groups (p < 0.01). The results also indicated that there were no statistically significant differences between group scores across time (p = 0.215). The statistical power for this analysis was low (0.312), most likely due to the small sample size. However, the results did reveal a trend suggesting that the training improvements were greater for both the SSJ and KSJ groups compared with the CON (by 171% and 107%, respectively) although significance was not reached.

Conclusions:
Due to the observed trend, a replication of this study with a greater number of participants over a longer period of time is warranted.