title: CORE MUSCLE ACTIVITY DURING THE CLEAN AND JERK LIFT WITH BARBELL VERSUS SANDBAGS AND WATER BAGS.
abstract: OBJECTIVE
  While the traditional clean and jerk maneuver implies simultaneous participation of a large number of muscle groups, the use of this exercise with some variations to enhance core muscle activity remains uninvestigated. The purpose of this study was to compare the muscle activity during clean and jerk lift when performed with a barbell, sandbag and a water bag at same absolute load.
  
  
  METHODS
  Descriptive, repeated-measures study.
  
  
  METHODS
  Twenty-one young fit male university students (age: 25 ± 2.66 years; height: 180.71 ± 5.42 cm; body mass: 80.32 ± 9.8 kg; body fat percentage: 12.41 ± 3.56 %) participated. Surface electromyographic (EMG) signals were recorded from the anterior deltoid (AD), external oblique (OBLIQ), lumbar erector spinae (LUMB), and gluteus medius (GM) and were expressed as a percentage of the maximum voluntary isometric contraction (MVIC).
  
  
  RESULTS
  There were no significantly significant differences for AD muscle activity between conditions, whereas muscle activation values for OBLIQ (60%MVIC), GM (29%MVIC) and LUMB (85%MVIC) were significantly higher during the water bag power clean and jerk maneuver when compared with the other conditions.
  
  
  CONCLUSIONS
  The clean and jerk is an exercise that may be used to enhance core muscle activity. Performing the maneuver with water bags resulted in higher core muscle activity compared with sandbag and standard barbell versions.
  
  
  METHODS
  3.
authors.affiliation: Research Group in Sport and Health, Department of Physical Education and Sports, University of Valencia, Valencia, Spain.
authors.forename: Joaquin
authors.initials: J
authors.lastname: Calatayud
authors.affiliation: Research Group in Sport and Health, Department of Physical Education and Sports, University of Valencia, Valencia, Spain.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Colado
authors.affiliation: Research Group in Sport and Health, Department of Physical Education and Sports, University of Valencia, Valencia, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Martin
authors.affiliation: Department of Physical Therapy, University of Valencia, Valencia, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Casaña
authors.forename: Markus D
authors.initials: MD
authors.lastname: Jakobsen
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Denmark.
authors.forename: Lars L
authors.initials: LL
authors.lastname: Andersen
keywords: Muscle activation; olympic lift; resistance training; weight lifting