The effect of back squat depth and load on lower body muscle activity in group exercise participants

Sports Biomech. 2024 May;23(5):555-566. doi: 10.1080/14763141.2021.1875034. Epub 2021 Mar 4.


Les Mills BODYPUMPTM is a resistance training group exercise class with a low load, high repetition format. Squat training in BODYPUMPTM has two key variables: depth and load. The study aim was to determine the effect of these parameters on the mean and peak EMG amplitude of vastus lateralis, gluteus maximus, biceps femoris and lateral gastrocnemius. Ten female BODYPUMPTM participants (age 41 ± 9 years, height 161.9 ± 3.8 cm, mass 67.7 ± 7.0 kg) performed 1 × 7 squats under four conditions, representing every combination of two depths (90° knee angle and 125° knee angle) and two loads (23% bodyweight and 38% bodyweight). The main effect of depth was significant for mean and peak activity of vastus lateralis and gluteus maximus, and peak activity of biceps femoris and lateral gastrocnemius. The main effect of load was significant for mean and peak activity of gluteus maximus and lateral gastrocnemius. There was no depth * load interaction. These data can be used to inform BODYPUMPTM programme design and amplify the training effect of participation in group exercise classes.

Keywords: Bodypump; EMG; Les Mills; motion capture; resistance training.

MeSH terms

  • Adult
  • Biomechanical Phenomena
  • Electromyography
  • Exercise* / physiology
  • Female
  • Humans
  • Middle Aged
  • Muscle, Skeletal / physiology
  • Quadriceps Muscle / physiology
  • Resistance Training*