Strength Training: Should You Mix It Up?

Are you wondering whether you should stick with a fixed resistance training program—same exercises and repetition ranges—in every training session or whether it would be better to mix up exercises and rep ranges each session? A study published recently in PLOS ONE (2019; doi:10.1371/journal.pone.0226989) found that varying exercise selection not only increased motivation to train but also produced equivalent improvements in muscular adaptations.

To compare the two training methods, researchers recruited 19 healthy, resistance-trained young men ages 20–27 for an 8-week program. The men were randomly assigned to either a control group or an experimental group. Control group members performed traditional resistance training consisting of three sets of six exercises performed four times per week. Experimental group participants trained with the same duration and frequency but did randomly chosen exercises for the upper and lower body and the posterior chain. Researchers assessed intrinsic motivation, body composition, muscle thickness and dynamic strength.

Data analysis found that variable-training participants had a significant, moderate improvement in intrinsic motivation to train, while the control group showed a nonsignificant decrease in motivation. No significant differences were noted between groups with respect to muscular adaptations. Study authors suggested that regularly changing exercise selection may improve adherence to resistance training in those who lack motivation.