Muscle activation during resistance exercise at 70% and 90% 1-repetition maximum in resistance-trained men

Muscle Nerve. 2017 Sep;56(3):505-509. doi: 10.1002/mus.25509. Epub 2017 Apr 2.


Introduction: Muscle activation was investigated during resistance exercise with 2 relatively high-intensity loads.

Methods: Ten resistance-trained men performed the leg press exercise to repetition failure: a set at 70% of 1-repetition maximum (1RM) and a set at 90% of 1RM. Surface electromyography (EMG) was used to assess peak and mean muscle activation of the vastus lateralis, rectus femoris, and vastus medialis.

Results: Peak and mean EMG remained greater at 90% than 70% 1RM across all repetitions (P = 0.03 and P = 0.02, respectively). Main effects for trial were also significant for mean EMG activity of the final common repetitions (P = 0.03) favoring 90% 1RM; however, peak EMG activity was similar during the final common repetitions of the 70% and 90% 1RM sets.

Conclusions: Across all repetitions, 90% 1RM appears to produce greater muscle activation during the leg press exercise, but similar peak EMG was observed during the final common repetitions of each set. Muscle Nerve 56: 505-509, 2017.

Keywords: EMG; electromyography; intensity; muscle activation; muscle activity; resistance training.

MeSH terms

  • Adult
  • Electromyography / methods*
  • Exercise / physiology*
  • Humans
  • Male
  • Muscle Strength / physiology*
  • Quadriceps Muscle / physiology*
  • Resistance Training / methods*
  • Weight-Bearing / physiology*
  • Young Adult