Muscle adaptations following 21 consecutive days of strength test familiarization compared with traditional training

Muscle Nerve. 2017 Aug;56(2):307-314. doi: 10.1002/mus.25488. Epub 2017 Mar 3.


Introduction: Large increases in 1-repetition maximum (1RM) strength have been demonstrated from repeated testing, but it is unknown whether these increases can be augmented by resistance training.

Methods: Five trained individuals performed a 1RM test and maximal voluntary isometric contraction (MVC) for unilateral elbow flexion exercise on 1 arm (testing arm), while the other arm performed a 1RM test and MVC, in addition to 3 sets of exercise (70% 1RM) (training arm), for 21 straight days.

Results: Although only the training arm had increased muscle thickness [mean 0.28 cm, 95% confidence interval (CI) 0.22-0.33 cm], 1RM strength increased similarly in the training (2.2 kg, 95% CI 0.9-3.4 kg; P = 0.008) and testing (1.9 kg, 95% CI 0.5-3.2 kg; P = 0.019) arms.

Conclusion: Increases in 1RM strength from resistance training are related to the specificity of exercise and are likely driven by mechanisms other than muscle growth. Muscle Nerve 56: 307-314, 2017.

Keywords: familiarization; frequency; hypertrophy; resistance training; specificity.

MeSH terms

  • Adaptation, Physiological / physiology*
  • Adult
  • Arm / physiology
  • Female
  • Humans
  • Isometric Contraction / physiology*
  • Male
  • Muscle Strength / physiology*
  • Muscle, Skeletal / physiology*
  • Myalgia / etiology
  • Resistance Training / methods*
  • Time Factors
  • Visual Analog Scale
  • Young Adult