Experimental Brain Research

, Volume 162, Issue 1, pp 122–132 | Cite as

Age-related differences in rapid muscle activation after rate of force development training of the elbow flexors

  • Benjamin K. Barry
  • Geoffrey E. Warman
  • Richard G. Carson
Research Article

Abstract

In young adults, improvements in the rate of force development as a result of resistance training are accompanied by increases in neural drive in the very initial phase of muscle activation. The purpose of this experiment was to determine if older adults also exhibit similar adaptations in response to rate of force development (RFD) training. Eight young (21–35 years) and eight older (60–79 years) adults were assessed during the production of maximum rapid contractions, before and after four weeks of progressive resistance training for the elbow flexors. Young and older adults exhibited significant increases (P<0.01) in peak RFD, of 25.6% and 28.6% respectively. For both groups the increase in RFD was accompanied by an increase in the root mean square (RMS) amplitude and in the rate of rise (RER) in the electromyogram (EMG) throughout the initial 100 ms of activation. For older adults, however, this training response was only apparent in the brachialis and brachioradialis muscles. This response was not observed in surface EMG recorded from the biceps brachii muscle during either RFD testing or throughout training, nor was it observed in the pronator teres muscle. The minimal adaptations observed for older adults in the bifunctional muscles biceps brachii and pronator teres are considered to indicate a compromise of the neural adaptations older adults might experience in response to resistance training.

Keywords

Ageing Strength Resistance training Biceps brachii Motor unit 

Abbreviations

MVC

Maximum voluntary contraction

RTD

Rate of torque development

EMG

Electromyography

RMS

Root mean square

RER

Rate of EMG rise

Notes

Acknowledgments

The authors wish to thank Mr Jonathan Shemmell, and Mr Andrew Popple for their assistance in data analysis, Mr Angus Ross for his helpful comments on the manuscript, and the volunteers who so generously donated their time. This work was supported by The Australian Research Council and The National Health and Medical Research Council.

References

  1. Aagaard P, Simonsen EB, Andersen JL, Magnusson P, Dyhre-Poulsen P (2002) Increased rate of force development and neural drive of human skeletal muscle following resistance training. J Appl Physiol 93:1318–1326PubMedGoogle Scholar
  2. Barry BK, Carson RG (2004) The consequences of resistance training for movement control in older adults. J Gerontol A Biol Sci Med Sci 59:M730–M754Google Scholar
  3. Bosco C, Komi PV (1980) Influence of aging on the mechanical behavior of leg extensor muscles. Eur J Appl Physiol Occup Physiol 45:209–219Google Scholar
  4. Carroll TJ, Riek S, Carson RG (2002) The sites of neural adaptation induced by resistance training in humans. J Physiol 544:641–652PubMedGoogle Scholar
  5. Carson RG, Riek S (2001) Changes in muscle recruitment patterns during skill acquisition. Exp Brain Res 138:71–87CrossRefPubMedGoogle Scholar
  6. Cohen J (1969) Statistical power analysis for the behavioural sciences. Academic Press, New YorkGoogle Scholar
  7. Day SJ, Hulliger M (2001) Experimental simulation of cat electromyogram: evidence for algebraic summation of motor-unit action-potential trains. J Neurophysiol 86:2144–2158PubMedGoogle Scholar
  8. Enoka RM (1997) Neural adaptations with chronic physical activity. J Biomech 30:447–455CrossRefPubMedGoogle Scholar
  9. Ettema G, Styles G, Kippers V (1998) The moment arms of 23 muscle segments of the upper limb with varying elbow and forearm positions: implications for motor control. Hum Mov Sci 17:201–220CrossRefGoogle Scholar
  10. Evans WJ (2000) Exercise strategies should be designed to increase muscle power. J Gerontol A Biol Sci Med Sci 55:M309–M310PubMedGoogle Scholar
  11. Farina D, Merletti R, Enoka RM (2004) The extraction of neural strategies from the surface EMG. J Appl Physiol 96:1486–1495CrossRefPubMedGoogle Scholar
  12. Ferri A, Scaglioni G, Pousson M, Capodaglio P, Van Hoecke J, Narici MV (2003) Strength and power changes of the human plantar flexors and knee extensors in response to resistance training in old age. Acta Physiol Scand 177:69–78CrossRefPubMedGoogle Scholar
  13. Fielding RA, LeBrasseur NK, Cuoco A, Bean J, Mizer K, Fiatarone Singh MA (2002) High-velocity resistance training increases skeletal muscle peak power in older women. J Am Geriatr Soc 50:655–662CrossRefPubMedGoogle Scholar
  14. Foldvari M, Clark M, Laviolette LC, Bernstein MA, Kaliton D, Castaneda C, Pu CT, Hausdorff JM, Fielding RA, Singh MA (2000) Association of muscle power with functional status in community-dwelling elderly women. J Gerontol A Biol Sci Med Sci 55:M192–M199PubMedGoogle Scholar
  15. Grabiner MD, Enoka RM (1995) Changes in movement capabilities with aging. Exerc Sport Sci Rev 23:65–104PubMedGoogle Scholar
  16. Hakkinen K, Hakkinen A (1991) Muscle cross-sectional area, force production and relaxation characteristics in women at different ages. Eur J Appl Physiol Occup Physiol 62:410–414PubMedGoogle Scholar
  17. Hakkinen K, Kallinen M, Izquierdo M, Jokelainen K, Lassila H, Malkia E, Kraemer WJ, Newton RU, Alen M (1998) Changes in agonist-antagonist EMG, muscle CSA, and force during strength training in middle-aged and older people. J Appl Physiol 84:1341–1349PubMedGoogle Scholar
  18. Izquierdo M, Aguado X, Gonzalez R, Lopez JL, Hakkinen K (1999) Maximum and explosive force production capacity and balance performance in men of different ages. Eur J Appl Physiol Occup Physiol 79:260–267CrossRefPubMedGoogle Scholar
  19. Jamison JC, Caldwell GE (1993) Muscle synergies and isometric torque production: influence of supination and pronation level on elbow flexion. J Neurophysiol 70:947–960PubMedGoogle Scholar
  20. Kamen G, Knight CA, Laroche DP, Asermely DG (1998) Resistance training increases vastus lateralis motor unit firing rates in young and old adults. Med Sci Sports Exerc 30:s337CrossRefGoogle Scholar
  21. Keenan KG, Farina D, Maluf KS, Merletti R, Enoka RM (2004) The influence of amplitude cancellation on the simulated surface electromyogram. J Appl Physiol:00894.02004Google Scholar
  22. MacConaill MA, Basmajian JV (1977) Muscles and movements: a basis for human kinesiology. Krieger, Huntington, New YorkGoogle Scholar
  23. Merletti R, Rainoldi A, Farina D (2001) Surface electromyography for noninvasive characterization of muscle. Exerc Sport Sci Rev 29:20–25CrossRefPubMedGoogle Scholar
  24. Milner-Brown HS, Stein RB, Lee RG (1975) Synchronization of human motor units: possible roles of exercise and supraspinal reflexes. Electroencephalogr Clin Neurophysiol 38:245–254CrossRefPubMedGoogle Scholar
  25. Moritani T, deVries HA (1979) Neural factors versus hypertrophy in the time course of muscle strength gain. Am J Phys Med 58:115–130PubMedGoogle Scholar
  26. Moritani T, deVries HA (1980) Potential for gross muscle hypertrophy in older men. J Gerontol 35:672–682PubMedGoogle Scholar
  27. Nelson AG (1996) Supramaximum activation increases motor unit velocity of unloaded shortening. J Appl Biomech 12:285–291Google Scholar
  28. Patten CT (2000) Reeducating muscle force control in older persons through strength training. Top Geriatric Rehabil 15:47–59Google Scholar
  29. Patten CT, Kamen G, Rowland DM (2001) Adaptations in maximum motor unit discharge rate to strength training in young and older adults. Muscle Nerve 24:542–550CrossRefPubMedGoogle Scholar
  30. Reeves ND, Maganaris CN, Narici MV (2003) Effect of strength training on human patella tendon mechanical properties of older individuals. J Physiol. 548:971–981Google Scholar
  31. Rice CL, Cunningham DA, Paterson DH, Dickinson JR (1993) Strength training alters contractile properties of the triceps brachii in men aged 65–78 years. Eur J Appl Physiol Occup Physiol 66:275–280CrossRefPubMedGoogle Scholar
  32. Semmler JG (2002) Motor unit synchronization and neuromuscular performance. Exerc Sport Sci Rev 30:8–14CrossRefPubMedGoogle Scholar
  33. Suzuki T, Bean JF, Fielding RA (2001) Muscle power of the ankle flexors predicts functional performance in community-dwelling older women. J Am Geriatr Soc 49:1161–1167CrossRefPubMedGoogle Scholar
  34. Van Cutsem M, Duchateau J, Hainaut K (1998) Changes in single motor unit behaviour contribute to the increase in contraction speed after dynamic training in humans. J Physiol 513:295–305PubMedGoogle Scholar
  35. Vandervoort AA (2002) Aging of the human neuromuscular system. Muscle Nerve 25:17–25CrossRefPubMedGoogle Scholar
  36. Wang FC, de Pasqua V, Delwaide PJ (1999) Age-related changes in fastest and slowest conducting axons of thenar motor units. Muscle Nerve 22:1022–1029PubMedGoogle Scholar
  37. Yao W, Fuglevand RJ, Enoka RM (2000) Motor-unit synchronization increases EMG amplitude and decreases force steadiness of simulated contractions. J Neurophysiol 83:441–452PubMedGoogle Scholar

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  • Benjamin K. Barry
    • 1
    • 2
  • Geoffrey E. Warman
    • 1
  • Richard G. Carson
    • 1
  1. 1.Perception and Motor Systems Laboratory, School of Human Movement StudiesThe University of QueenslandSt LuciaAustralia
  2. 2.Neural Control of Movement Laboratory, Department of Integrative PhysiologyUniversity of ColoradoBoulderUSA

Personalised recommendations