An external focus—on what you want to achieve—may benefit strength training performance most. A recent systematic review analyzed research to determine which mental focus improves weightlifting performance. Three options are possible: external focus on the intended weightlifting result, internal focus on the body or no specific focus.
A Griffith University researcher in Australia conducted a review of 16 studies and found that focusing externally—for example, visualizing the bar or weight being lifted or pushed away in a competition to achieve a personal best—maximizes muscular efficiency and force production accuracy. As movement complexity increases (as in a compound or multijoint movement), the benefits of maintaining an external focus to improve performance become even more pronounced.
In contrast, the analysis showed that concentrating internally on the muscles being used during an exercise is superior for boosting muscle growth and increasing strength.
More research is needed to learn more about maximizing attentional focus for performance gains.
The review is available at Frontiers in Sports and Active Living (2019; doi:10.3389/fspor.2019.0007).