Int J Sports Med 2003; 24(6): 410-418
DOI: 10.1055/s-2003-41171
Physiology & Biochemistry
© Georg Thieme Verlag Stuttgart · New York

Acute Hormonal and Neuromuscular Responses and Recovery to Forced vs. Maximum Repetitions Multiple Resistance Exercises

J.  P.  Ahtiainen1 , A.  Pakarinen2 , W.  J.  Kraemer3 , K.  Häkkinen1
  • 1Neuromuscular Research Center & Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, Finland
  • 2Department of Clinical Chemistry, University of Oulu, Oulu, Finland
  • 3The Human Performance Laboratory, Department of Kinesiology, The University of Connecticut, Storrs, CT, USA
Further Information

Publication History

Accepted after revision: November 20, 2002

Publication Date:
07 August 2003 (online)


Acute hormonal and neuromuscular responses and recovery three days after the exercises were examined during the maximum repetitions (MR) and forced repetitions (FR) resistance exercise protocols in 16 male athletes. MR included 4 sets of leg presses, 2 sets of squats and 2 sets of knee extensions (with 12 RM) with a 2-min recovery between the sets and 4 min between the exercises. In FR the initial load was chosen to be higher than in MR so that the subject could not lift 12 repetitions per set by himself. After each set to failure the subject was assisted to perform the remaining repetitions to complete the 12 repetitions per set. Thus the exercise intensity was greater in FR than in MR. Both loading protocols led to the great acute increases (p < 0.05 - 0.001) in serum testosterone, free testosterone, cortisol and GH concentrations. However, the responses in cortisol (p < 0.05) and GH (p < 0.01) were larger in FR than in MR. The decrease of 56.5 % (p < 0.001) in maximal isometric force in FR was greater (p < 0.001) than that of 38.3 % in MR (p < 0.001) and force remained lower (p < 0.01) during the recovery in FR compared to MR. The larger decrease in isometric strength in FR than in MR was also associated with the decreased maximal voluntary EMG of the loaded muscles. The data indicate that the forced repetition exercise system induced greater acute hormonal and neuromuscular responses than a traditional maximum repetition exercise system and therefore it may be used to manipulate acute resistance exercise variables in athletes.


  • 1 Beitins I Z, Bayard F, Kowarski A, Migeon C J. The effect of ACTH administration on plasma testosterone, dihydrotestosterone and serum LH concentrations in normal men.  Steroids. 1973;  21 553-564
  • 2 Biolo G, Tipton K D, Klein S, Wolfe R R. An abundant supply of amino acids enhances the metabolic effect of exercise on muscle protein.  Am J Physiol. 1997;  273 E122-E129
  • 3 Bosco C, Colli R, Bonomi R, von Duvillard S P, Viru A. Monitoring strength training: neuromuscular and hormonal profile.  Med Sci Sports Exerc. 2000;  32 202-208
  • 4 Crist D M, Peake G T, Loftfield R B, Kraner J C, Egan P A. Supplemental growth hormone alters body composition, muscle protein metabolism and serum lipids in fit adults: characterization of dose-dependent and response-recovery effects.  Mech Ageing Dev. 1991;  58 191-205
  • 5 Doumit M E, Cook D R, Merkel R A. Testosterone up-regulates androgen receptors and decreases differentiation of porcine myogenic satellite cells in vitro.  Endocrinology. 1996;  137 1385-1394
  • 6 Durnin J V, Rahaman M M. The assessment of the amount of fat in the human body from measurements of skinfold thickness.  Br J Nutr. 1967;  21 681-689
  • 7 Eik-Nes K B. An effect of isoproterenol on rates of synthesis and secretion of testosterone.  Am J Physiol. 1969;  217 1764-1770
  • 8 Fahrner C L, Hackney A C. Effects of endurance exercise on free testosterone concentration and the binding affinity of sex hormone binding globulin (SHBG).  Int J Sports Med. 1998;  19 12-15
  • 9 Fleck S J, Kraemer W J. Designing Resistance Training Programs. 2nd ed. Champaign, Illinois; Human Kinetics 1997: 117
  • 10 Florini J R. Hormonal control of muscle growth.  Muscle Nerve. 1987;  10 577-598
  • 11 Gordon S E, Kraemer W J, Vos N H, Lynch J M, Knuttgen H G. Effect of acid-base balance on the growth hormone response to acute high-intensity cycle exercise.  J Appl Physiol. 1994;  76 821-829
  • 12 Gosselink K L, Grindeland R E, Roy R R, Zhong H, Bigbee A J, Grossman E J, Edgerton V R. Skeletal muscle afferent regulation of bioassayable growth hormone in the rat pituitary.  J Appl Physiol. 1998;  84 1425-1430
  • 13 Green H J. Mechanism of muscle fatigue in intense exercise.  J Sports Sciences. 1997;  15 247-256
  • 14 Häkkinen K, Pakarinen A, Alen M, Kauhanen H, Komi P V. Neuromuscular and hormonal responses in elite athletes to two successive strength training sessions in one day.  Eur J Appl Physiol. 1988;  57 133-139
  • 15 Häkkinen K, Pakarinen A, Kraemer W J, Newton R U, Alen M. Basal concentrations and acute responses of serum hormones and strength development during heavy resistance training in middle-aged and elderly men and women.  J Gerontol A Biol Sci Med Sci. 2000;  55 B95-105
  • 16 Häkkinen K, Pakarinen A. Acute hormonal responses to two different fatiguing heavy-resistance protocols in male athletes.  J Appl Physiol. 1993;  74 882-887
  • 17 Häkkinen K. Neuromuscular fatigue and recovery in male and female athletes during heavy resistance exercise.  Int J Sports Med. 1993;  14 53-59
  • 18 Jezova D, Vigas M. Testosterone response to exercise during blockade and stimulation of adrenergic receptors in man.  Horm Res. 1981;  15 141-147
  • 19 Kjaer M, Secher N H, Bach F W, Galbo H. Role of motor center activity for hormonal changes and substrate mobilization in humans.  Am J Physiol. 1987;  253 R687-R695
  • 20 Kjaer M. Regulation of hormonal and metabolic responses during exercise in humans.  Exerc Sport Sci Rev. 1987;  20 161-184
  • 21 Komi P V, Rusko H. Quantitative evaluation of mechanical and electrical changes during fatigue loading of eccentric and concentric work.  Scand J Rehabil Med Suppl. 1974;  3 121-126
  • 22 Kraemer W J, Häkkinen K, Newton R U, McCormick M, Nindl B C, Volek J S, Gotshalk L A, Fleck S J, Campbell W W, Gordon S E, Farrell P A, Evans W J. Acute hormonal responses to heavy resistance exercise in younger and older men.  Eur J Appl Physiol. 1998;  77 206-211
  • 23 Kraemer W J, Marchitelli L, Gordon S E, Harman E, Dziados J E, Mello R, Frykman P, McCurry D, Fleck S J. Hormonal and growth factor responses to heavy resistance exercise protocols.  J Appl Physiol. 1990;  69 1442-1450
  • 24 Kraemer W J, Noble B J, Clark M J, Culver B W. Physiologic responses to heavy-resistance exercise with very short rest periods.  Int J Sports Med. 1987;  8 247-252
  • 25 Linnamo V, Hakkinen K, Komi P V. Neuromuscular fatigue and recovery in maximal compared to explosive strength loading.  Eur J Appl Physiol. 1998;  77 176-181
  • 26 MacAdams M R, White R H, Chipps B E. Reduction of serum testosterone levels during chronic glucocorticoid therapy.  Ann Intern Med. 1986;  104 648-651
  • 27 Mooradian A D, Morley J E, Korenman S G. Biological actions of androgens.  Endocr Rev. 1987;  8 1-28
  • 28 Nosaka K, Clarkson P M, McGuiggin M E, Byrne J M. Time course of muscle adaptation after high force eccentric exercise.  Eur J Appl Physiol. 1991;  63 70-76
  • 29 Staron R S, Karapondo D L, Kraemer W J, Fry A C, Gordon S E, Falkel J E, Hagerman F C, Hikida R S. Skeletal muscle adaptations during early phase of heavy-resistance training in men and women.  J Appl Physiol. 1994;  76 1247-1255
  • 30 Staron R S, Malicky E S, Leonardi M J, Falkel J E, Hagerman F C, Dudley G A. Muscle hypertrophy and fast fiber type conversions in heavy resistance-trained women.  Eur J Appl Physiol. 1990;  60 71-79
  • 31 Tarnopolsky M A, Atkinson S A, MacDougall J D, Chesley A, Phillips S, Schwarcz H P. Evaluation of protein requirements for trained strength athletes.  J Appl Physiol. 1992;  73 1986-1995
  • 32 Viru A. Plasma hormones and physical exercise.  Int J Sports Med. 1992;  13 201-209
  • 33 Viru A. Postexercise recovery period: carbohydrate and protein metabolism.  Scand J Med Sci Sports. 1996;  6 2-14
  • 34 Volek J S, Kraemer W J, Bush J A, Incledon T, Boetes M. Testosterone and cortisol in relationship to dietary nutrients and resistance exercise.  J Appl Physiol. 1997;  82 49-54

J. Ahtiainen

Department of Biology of Physical Activity · University of Jyväskylä

P.O. Box 35 · 40014 University of Jyväskylä · Finland ·

Phone: +358-14-2602083

Fax: +358-14-2602071