title: Effects of Loaded Squat Exercise with and without Application of Superimposed EMS on Physical Performance.
abstract: The aim of the present study was to investigate the effects of a multiple set squat exercise training intervention with superimposed electromyostimulation (EMS) on strength and power, sprint and jump performance. Twenty athletes from different disciplines participated and were divided into two groups: strength training (S) or strength training with superimposed EMS (S+E). Both groups completed the same training program twice a week over a six week period consisting of four sets of the 10 repetition maximum of back squats. Additionally, the S+E group had EMS superimposed to the squat exercise with simultaneous stimulation of leg and trunk muscles. EMS intensity was adjusted to 70% of individual pain threshold to ensure dynamic movement. Strength and power of different muscle groups, sprint, and vertical jump performance were assessed one week before (pre), one week after (post) and three weeks (re) following the training period. Both groups showed improvements in leg press strength and power, countermovement and squat jump performance and pendulum sprint (p < 0.05), with no changes for linear sprint. Differences between groups were only evident at the leg curl machine with greater improvements for the S+E group (p < 0.05). Common squat exercise training and squat exercise with superimposed EMS improves maximum strength and power, as well as jumping abilities in athletes from different disciplines. The greater improvements in strength performance of leg curl muscles caused by superimposed EMS with improvements in strength of antagonistic hamstrings in the S+E group are suggesting the potential of EMS to unloaded (antagonistic) muscle groups. Key pointsSimilar strength adaptations occurred after a 6 week 10 RM back squat exercise program with superimposed EMS (S+E) and 10 RM back squat exercise (S) alone.Specific adaptations for S+E at the leg curl muscles were evident.S and S+E improved SJ, CMJ and pendulum sprint performance.No improvement occurred in linear sprint performance.
authors.affiliation: Institute of Training Science and Sport Informatics, German Sport University and German Research Center of Elite Sport , Cologne, Germany.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Wirtz
authors.affiliation: Institute of Training Science and Sport Informatics, German Sport University and German Research Center of Elite Sport , Cologne, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Zinner
authors.affiliation: Institute of Training Science and Sport Informatics, German Sport University and German Research Center of Elite Sport , Cologne, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Doermann
authors.affiliation: Institute of Training Science and Sport Informatics, German Sport University and German Research Center of Elite Sport , Cologne, Germany.
authors.forename: Heinz
authors.initials: H
authors.lastname: Kleinoeder
authors.affiliation: Institute of Training Science and Sport Informatics, German Sport University and German Research Center of Elite Sport , Cologne, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Mester
keywords: Electrical stimulation; MVC; change of direction speed; jump height; peak power output; sprint; strength training