Imagery Increases Muscle Strength
Researchers from the Centre of Research and Innovation in Sport, at the University Claude Bernard and the University of Lyon in Villeurbanne, France, examined whether mental imagery (MI) training can increase muscle strength, especially when movements are under the control of large cortical areas in the primary motor cortex. (It has already been well established that it improves motor performance and motor learning.)
This pilot study experiment assessed whether MI can improve upper and lower limb strength, with complex, multi-joint exercises.
Nine participants were included in the MI group and 10 in the control (CTRL) group. The 2 groups performed identical bench press and leg press exercises. The MI group was instructed to visually imagine and kinesthetically feel the corresponding contractions during the rest period, whereas the CTRL group carried out a neutral task.
Differences were measured by maximal voluntary contractions (MVC) and maximal number of repetitions (MR), using 80% of the pre-test MVC weight.
Although both the experimental and control groups enhanced their strength through the training sessions, the leg press MVC was significantly higher in the MI group than in the CTRL group (p<0.05). The interaction between the leg press MR and the group was marginally significant (p=0.076). However, investigators did not find any difference between the MI and CTRL groups, both in the bench press MVC or MR.
They conclude that MI-related training may contribute to the improvement of lower limbs performance by enhancing the technical execution of the movement, and the individual intrinsic motivation.
From an applied and practical perspective, they report that athletes may perform imagined muscles contractions, most especially during the rest periods of their physical training, to contribute to the enhancement of concentric strength.
Citation: Lebon F, Collet C, Guillot A. Benefits of motor imagery training on muscle strength. Journal of Strength and Conditioning Research. 2010 Jun; 24 (6): pp. 1680-7.