Changes in force, cross-sectional area and neural activation during strength training and detraining of the human quadriceps

  • M. V. Narici
  • G. S. Roi
  • L. Landoni
  • A. E. Minetti
  • P. Cerretelli


Four male subjects aged 23–34 years were studied during 60 days of unilateral strength training and 40 days of detraining. Training was carried out four times a week and consisted of six series of ten maximal isokinetic knee extensions at an angular velocity of 2.09 rad·s−1. At the start and at every 20th day of training and detraining, isometric maximal voluntary contraction (MVC), integrated electromyographic activity (iEMG) and quadriceps muscle cross-sectional area (CSA) assessed at seven fractions of femur length (Lf), by nuclear magnetic resonance imaging, were measured on both trained (T) and untrained (UT) legs. Isokinetic torques at 30° before full knee extension were measured before and at the end of training at: 0, 1.05, 2.09, 3.14, 4.19, 5.24 rad·s−1. After 60 days T leg CSA had increased by 8.5%±1.4% (mean±SEM,n=4,p<0.001), iEMG by 42.4%±16.5% (p<0.01) and MVC by 20.8%±5.4% (p<0.01). Changes during detraining had a similar time course to those of training. No changes in UT leg CSA were observed while iEMG and MVC increased by 24.8%±10% (N.S.) and 8.7%±4.3% (N.S.), respectively. The increase in quadriceps muscle CSA was maximal at 2/10 Lf (12.0%±1.5%,p<0.01) and minimal, proximally to the knee, at 8/10 Lf (3.5%±1.2%, N.S.). Preferential hypertrophy of the vastus medialis and intermedius muscles compared to those of the rectus femoris and lateralis muscles was observed. Isoangular torque of T leg increased by 20.9%±5.4% (p<0.05), 23.8%±7.8% (p<0.05) and 22.5%±6.7% (p<0.05) at 0, 1.05 and 2.09 rad·s−1 respectively; no significant change was observed at higher velocities and in the UT leg. Hypertrophy produced by strength training accounts for 40% of the increase in force while the remaining 60% seems to be attributable to an increased neural drive and possibly to changes in muscle architecture.

Key words

Strength training/detraining Hypertrophy EMG Nuclear magnetic resonance imaging 


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  1. Alexander RMcN, Vernon A (1975) The dimensions of knee and ankle muscles and the forces they exert. J Mov Stud 1:115–123Google Scholar
  2. Bonde Petersen F (1960) Muscle training by static, concentric and eccentric contractions. Acta Physiol Scand 48:406–416Google Scholar
  3. Caiozzo VJ, Perrine JJ, Edgerton VR (1981) Training-induced alterations of the in vivo force-velocity relationship of human muscle. J Appl Physiol 51:750–754PubMedGoogle Scholar
  4. Cannon RJ, Cafarelli E (1987) Neuromuscular adaptations to training. J Appl Physiol 63:2396–2402PubMedGoogle Scholar
  5. Close RI (1972) Dynamic properties of mammalian skeletal muscles. Physiol Rev 52:129–197PubMedGoogle Scholar
  6. Costill DL, Coyle EF, Fink WF, Lesmes GR, Witzmann FA (1979) Adaptations in skeletal muscle following strength training. J Appl Physiol 46:96–99PubMedGoogle Scholar
  7. Davies CTM, Dooley P, McDonagh MJN, White MJ (1985) Adaptation of mechanical properties of muscle to high force training in man. J Physiol 365:227–284Google Scholar
  8. Davies J, Parker DF, Rutherford OM, Jones DA (1988) Changes in strength and cross sectional area of the elbow flexors as a result of isometric strength training. Eur J Appl Physiol 57:667–670CrossRefGoogle Scholar
  9. Edwards RHT, Young A, Hosking GP, Jones DA (1977) Human skeletal muscle function: description of tests and normal values. Cli Sci Mol Med 52:283–290Google Scholar
  10. Fukunaga T (1976) Die absolute Muskelkraft und das Muskelkrafttraining. Sportarzt Sportmed 11:255–265Google Scholar
  11. Goldspink G (1985) Malleability of the motor system: a comparative approach. J Exp Biol 115:375–391PubMedGoogle Scholar
  12. Hakkinen K, Komi PV (1983) Electromyographic changes during strength training and detraining. Med Sci Sports Exerc 15:445–460Google Scholar
  13. Hakkinen K, Alén M, Komi PV (1985) Changes in isometric force and relaxation time, electromyographic and muscle fibre characteristics of human skeletal muscle during strength training and detraining. Acta Physiol Scand 125:573–585PubMedGoogle Scholar
  14. Hakkinen K, Komi PV, Tesch P (1981) The effect of combined concentric and eccentric strength training and detraining on force-time, muscle fiber, and metabolic characteristics of leg extensor muscles. Scand J Sports Sci 3:50–58Google Scholar
  15. Ikai M, Fukunaga T (1970) A study on training effect on strength per unit cross-sectional area of muscle by means of ultrasonic measurement. Eur J Appl Physiol 28:173–180Google Scholar
  16. Ikai M, Steinhaus AH (1961) Some factors modifying the expression of human strength. J Appl Physiol 19:157–163Google Scholar
  17. Johnson MA, Polgar J, Weightman D, Appleton (1973) Data on the distribution of fibre types in thirty-six human muscles — an autopsy study. J Neurol Sci 18:111–129CrossRefPubMedGoogle Scholar
  18. Jones DA, Rutherford OM (1987) Human muscle strength training: the effects of three different regimes and the nature of the resultant changes. J Physiol 391:1–11PubMedGoogle Scholar
  19. Jones DA, Rutherford OM, Parker DF (1989) Physiological changes in skeletal muscle as a result of strength training. Q J Exp Physiol 74:233–256PubMedGoogle Scholar
  20. Komi PV, Viitasalo JT, Rauramaa R, Vihko V (1978) Effect of isometric strength training on mechanical, and metabolic aspects of muscle function. Eur J Appl Physiol 40:45–55CrossRefGoogle Scholar
  21. Komi PV (1986) How important is neural drive for strength and power development in human skeletal muscle? In: Saltin B (ed) Biochemistry of Exercise VI. International series on sports sciences, vol 16. Human Kinetics, Champaign, Ill, pp 515–529Google Scholar
  22. Lawrence JH, De Luca CJ (1983) Myoelectric signal versus force relationship in different human muscles. J Appl Physiol 54:1653–1659PubMedGoogle Scholar
  23. Lesmes GR, Costill DL, Coyle EF, Fink WJ (1978) Muscle strength and power changes during maximal isokinetic loading. Med Sci Sports 10:266–269PubMedGoogle Scholar
  24. Lind AR, Petrowsky JS (1978) Isometric tension from rotary stimulation of fast and slow cat muscle. Muscle Nerve 1:213–218CrossRefPubMedGoogle Scholar
  25. Luthi JM, Howald H, Claassen H, Rosler K, Vock P, Hoppeler H (1986) Structural changes in skeletal muscle tissue with heavy-resistance exercise. Int J Sports Med 7:123–127PubMedGoogle Scholar
  26. MacDougall JD (1986) Adaptability of muscle to strength training — a cellular approach. In: Saltin B (ed) Biochemistry of exercise VI. International series on sport sciences, vol 16. Human kinetics, Champaign, Ill, pp 501–514Google Scholar
  27. MacDougall JD, Ward GR, Sale DG, Sutton JR (1977) Biochemical adaptation of human skeletal muscle to heavy resistance training and immobilization. J Appl Physiol 43:700–703PubMedGoogle Scholar
  28. McDounagh MJN, Davies CTM (1984) Adaptive response of mammalian skeletal muscle to exercise at high loads. Eur J Appl Physiol 52:139–155Google Scholar
  29. Milner-Brown HS, Stein RB, Yemm R (1973) The orderly recruitment of human motor units during voluntary isometric contractions. J Physiol 230:359–370PubMedGoogle Scholar
  30. Milner-Brown HS, Stein RB, Lee RG (1975) Synchronization of human motor units: possible roles of exercise and supraspinal reflexes. Electroencephalogr Clin Neurophysiol 38:245–254PubMedGoogle Scholar
  31. Moffroid MT, Whipple RH (1970) Specificity of speed of exercise. Phys Ther 50:1693–1699Google Scholar
  32. Moritani T, de Vries HA (1979) Neural factors versus hypertrophy in the time course of muscle strength gain. Am J Phys Med 58:115–130PubMedGoogle Scholar
  33. Narici MV, Roi GS, Landoni L (1988) Force of knee extensor and flexor muscles and cross-sectional area determined by nuclear magnetic resonance imaging. Eur J Appl Physiol 57:39–44CrossRefGoogle Scholar
  34. Perrine JJ, Edgerton VR (1979) Muscle force-velocity and power-velocity relationship under isokinetic loading. Med Sci Sports 10:159–166Google Scholar
  35. Rutherford OM, Jones DA (1986) The role of learning and coordination in strength training. Eur J Appl Physiol 55:100–105Google Scholar
  36. Schiaffino S, Pierobon Bornioli SP, Aloisi M (1972) Cell proliferation in rat skeletal muscle during early stages of compensatory hypertrophy. Virchows Arch [B] 11:268–273Google Scholar
  37. Tabary JC, Tabart C, Tardieu C, Tardieu G, Goldspink G (1972) Physiological and structural changes in the cat's soleus muscle due to immobilization at different lengths by plaster casts. J Physiol 224:231–244PubMedGoogle Scholar
  38. Young A (1984) The relative isometric strength of type I and type II muscle fibres in the human quadriceps. Clin Physiol 4:23–32PubMedGoogle Scholar
  39. Young A, Stokes M, Round JM, Edwards RHT (1983) The effect of high resistance training on strength and cross-sectional area of the human quadriceps. Eur J Clin Invest 13:411–417PubMedGoogle Scholar
  40. Williams PE, Goldspink G (1973) The effect of immobilization on the longitudinal growth of striated muscle fibres. J Anat 116:45–55PubMedGoogle Scholar

Copyright information

© Springer-Verlag 1989

Authors and Affiliations

  • M. V. Narici
    • 1
  • G. S. Roi
    • 1
  • L. Landoni
    • 2
  • A. E. Minetti
    • 1
  • P. Cerretelli
    • 1
  1. 1.Reparto Fisiologia Lavoro MuscolareI.T.B.A. C.N.R.MilanItaly
  2. 2.Servizio di RMN, Centro S. Pio XMilanItaly

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