Document Type : Research Paper I Open Access I Released under CC BY-NC 4.0 license


1 PhD. Candidate, Department of Sport Physiology, Faculty of Educational Sciences, Mohaghegh Ardabili University, Ardabil, Iran.

2 Associate Professor, Department of Sport Physiology, Faculty of Educational Sciences, Mohaghegh Ardabili University, Ardabil, Iran.

3 Assistance Professor, Department of Sport Physiology, University of Tabriz, Tabriz, Iran.

4 Professor, Department of Sport Physiology, Faculty of Educational Sciences, Mohaghegh Ardabili University, Ardabil, Iran.

5 Assistant Prof., Dept. Sport Physiology, Faculty of Educational Sciences and Psychology, University of Mohaghegh Ardabili, Ardabil, Iran


The present study investigates the effect of 8 weeks of continuous and high intensity interval training on serum GH/IGF-1 indices and performance of active young men. In this quasi-experimental study, 20 young men (18-25 years old) were selected and randomly assigned into two homogenous groups of continuous training (n=10) and HIIT (n=10) and participated in an eight-weeks training course. The main activity of the continuous training group consisted of 30-50 minutes of continuous running with an intensity of 50-70% of heart rate reserve (HRR). HIIT group training were three sets of four repetitions and 15-30 seconds of running with an intensity of 85-95% HRR in each repetition. Blood samplings were taken from all subjects in three stages of pre-test, immediately after the first session and 48 hours after the last training session. Investigations showed that after a session of continuous training or HIIT, the amount of total IGF-1 decreased significantly in both groups (P = 0.0001), while the serum concentration of GH significantly increased in both group (P=0.04). Moreover, after 8 weeks, none of the training methods caused a change in total IGF-1 concentration (P=0.78); But GH concentration increased in both groups (P=0.001). Also, free IGF-1 concentration increased significantly after 1 session and 8 weeks of training in both groups (P=0.001). On the other hand, ALS has decreased significantly in the third stage test in both groups (P=0.001) and IGFBP3 values ​​did not change in any of the two groups (P=0.64). Also, the increase in VO2max was significant in both groups (P=0.001), but this increase was greater in the HIIT group (P=0.032, F=5.49, 1.17). It seems that the use of both continuous and interval training methods can create positive adaptations toward improving participants’ cardiovascular endurance and health, but considering factors such as increasing free IGF-1 and VO2max, HIIT training is a more appropriate method.


Main Subjects

  1. Carter-Su C, Schwartz J, Argetsinger LS. Growth hormone signaling pathways. Growth Hormone & IGF Research. 2016;28:11-5.
  2. Kawai M. Role of GH/IGF-1 in bone growth and bone mass. Handbook of nutrition and diet in therapy of bone diseases: Wageningen Academic Publishers; 2016. p. 2674-82.
  3. Nindl BC, Pierce JR. Insulin-like growth factor I as a biomarker of health, fitness, and training status. Med Sci Sports Exerc. 2010;42(1):39-49.
  4. Varma Shrivastav S, Bhardwaj A, Pathak KA, Shrivastav A. Insulin-like growth factor binding protein-3 (IGFBP-3): unraveling the role in mediating IGF-independent effects within the cell. Frontiers in Cell and Developmental Biology. 2020:286.
  5. Baxter RC. Insulin-like growth factor binding protein-3 (IGFBP-3): Novel ligands mediate unexpected functions. J Cell Commun Signal. 2013;7(3):179-89.
  6. Domené S, Domené HM. The role of acid-labile subunit (ALS) in the modulation of GH-IGF-I action. Molecular and Cellular Endocrinology. 2020;518:111006.
  7. Nindl BC, Alemany JA, Tuckow AP, Kellogg MD, Sharp MA, Patton JF. Effects of exercise mode and duration on 24-h IGF-I system recovery responses. Medicine and science in sports and exercise. 2009;41(6):1261-70.
  8. Frystyk J. Exercise and the growth hormone-insulin-like growth factor axis. Med Sci Sports Exerc. 2010;42(1):58-66.
  9. Nindl BC, Alemany JA, Kellogg MD, Rood J, Allison SA, Young AJ, et al. Utility of circulating IGF-I as a biomarker for assessing body composition changes in men during periods of high physical activity superimposed upon energy and sleep restriction. Journal of Applied Physiology. 2007;103(1):340-6.
  10. de Araujo GG, Papoti M, dos Reis IGM, de Mello MA, Gobatto CA. Short and Long Term Effects of High-Intensity Interval Training on Hormones, Metabolites, Antioxidant System, Glycogen Concentration, and Aerobic Performance Adaptations in Rats. Frontiers in physiology. 2016;7.
  11. de Freitas MC, Gerosa-Neto J, Zanchi NE, Lira FS, Rossi FE. Role of metabolic stress for enhancing muscle adaptations: Practical applications. World Journal of Methodology. 2017;7(2):46.
  12. Kraemer WJ, Ratamess NA, Nindl BC. Recovery responses of testosterone, growth hormone, and IGF-1 after resistance exercise. Journal of Applied Physiology. 2017;122(3):549-58.
  13. Tolfrey K, Zakrzewski-Fruer JK, Smallcombe J. Metabolism and exercise during youth. Pediatric Exercise Science. 2017;29(1):39-44.
  14. Terada T, Beanlands RA, Tulloch HE, Pipe AL, Chirico D, Reed JL. Aerobic interval training and moderate-to-vigorous intensity continuous training are associated with sex-specific improvements in psychological health in patients with heart disease. European journal of preventive cardiology. 2019;26(8):888-91.
  15. Reed JL, Keast M-L, Beanlands RA, Blais AZ, Clarke AE, Pipe AL, et al. The effects of aerobic interval training and moderate-to-vigorous intensity continuous exercise on mental and physical health in women with heart disease. European journal of preventive cardiology. 2019;26(2):211-4.
  16. Wen D, Utesch T, Wu J, Robertson S, Liu J, Hu G, et al. Effects of different protocols of high intensity interval training for VO2max improvements in adults: A meta-analysis of randomised controlled trials. Journal of science and medicine in sport. 2019;22(8):941-7.
  17. Andrade V, Zagatto A, Kalva-Filho C, Mendes O, Gobatto C, Campos E, et al. Running-based anaerobic sprint test as a procedure to evaluate anaerobic power. International journal of sports medicine. 2015;36(14):1156-62.
  18. Peake JM, Tan SJ, Markworth JF, Broadbent JA, Skinner TL, Cameron-Smith D. Metabolic and hormonal responses to isoenergetic high-intensity interval exercise and continuous moderate-intensity exercise. American Journal of Physiology-Endocrinology and Metabolism. 2014;307(7):E539-E52.
  19. Gregory SM, Spiering BA, Alemany JA, Tuckow AP, Rarick KR, Staab JS, et al. Exercise-induced insulin-like growth factor I system concentrations after training in women. Medicine and science in sports and exercise. 2013;45(3):420-8.
  20. Leite S, Reis A, Colnezi G, Souza F, Ferracini H. Influence of Vascular Occlusion in Concentration of Growth Hormone and Lactate in Athletes during Strengthening Quadriceps Exercise. Occup Med Health Aff. 2015;3(195):2.
  21. Kliszczewicz B, Markert CD, Bechke E, Williamson C, Clemons KN, Snarr RL, et al. Acute Effect of Popular High-Intensity Functional Training Exercise on Physiologic Markers of Growth. J Strength Cond Res. 2021;35(6):1677-84.
  22. Yu AP, Ugwu FN, Tam BT, Lee PH, Lai CW, Wong CS, et al. One year of yoga training alters ghrelin axis in centrally obese adults with metabolic syndrome. Frontiers in physiology. 2018;9:1321.
  23. Herbert P, Hayes LD, Sculthorpe N, Grace FM. High-intensity interval training (HIIT) increases insulin-like growth factor-I (IGF-I) in sedentary aging men but not masters’ athletes: an observational study. The Aging Male. 2017;20(1):54-9.
  24. Hejazi SM. Effects of High Intensity Interval Training on Plasma Levels of GH and IGF-I. Health Sciences. 2017;6(4):55-9.
  25. Sasaki H, Morishima T, Hasegawa Y, Mori A, Ijichi T, Kurihara T, et al. 4 weeks of high-intensity interval training does not alter the exercise-induced growth hormone response in sedentary men. SpringerPlus. 2014;3(1):336.
  26. Hackney AC, Davis HC, Lane AR. Growth Hormone-Insulin-Like Growth Factor Axis, Thyroid Axis, Prolactin, and Exercise. Sports Endocrinology. 47: Karger Publishers; 2016. p. 1-11.
  27. Sellami M, Dhahbi W, Hayes LD, Padulo J, Rhibi F, Djemail H, et al. Combined sprint and resistance training abrogates age differences in somatotropic hormones. PloS one. 2017;12(8).
  28. Tourinho Filho H, Pires M, Puggina EF, Papoti M, Barbieri R, Martinelli Jr C. Serum IGF-I, IGFBP-3 and ALS concentrations and physical performance in young swimmers during a training season. Growth Hormone & IGF Research. 2017;32:49-54.
  29. Sabag A, Chang D, Johnson NA. Growth Hormone as a Potential Mediator of Aerobic Exercise-Induced Reductions in Visceral Adipose Tissue. Frontiers in Physiology. 2021;12:362.
  30. Zinner C, Wahl P, Achtzehn S, Reed J, Mester J. Acute hormonal responses before and after 2 weeks of HIT in well trained junior triathletes. Int J Sports Med. 2014;35(4):316-22.
  31. Tourinho Filho H, Pires M, Puggina E, Papoti M, Barbieri R, Martinelli C. Serum IGF-I, IGFBP-3 and ALS concentrations and physical performance in young swimmers during a training season. Growth Hormone & IGF Research. 2017;32:49-54.
  32. Gatti R, De Palo E, Antonelli G, Spinella P. IGF-I/IGFBP system: metabolism outline and physical exercise. Journal of endocrinological investigation. 2012;35(7):699-707.
  33. Nindl BC, Alemany JA, Rarick KR, Eagle SR, Darnell ME, Allison KF, et al. Differential basal and exercise-induced IGF-I system responses to resistance vs. calisthenic-based military readiness training programs. Growth Hormone & IGF Research. 2017;32:33-40.
  34. Rajah R, Katz L, Nunn S, Solberg P, Beers T, Cohen P. Insulin-like growth factor binding protein (IGFBP) proteases: functional regulators of cell growth. Progress in growth factor research. 1995;6(2-4):273-84.
  35. Firth SM, Baxter RC. Cellular actions of the insulin-like growth factor binding proteins. Endocrine reviews. 2002;23(6):824-54.
  36. David A, Hwa V, Metherell LA, Netchine I, Camacho-Hübner C, Clark AJ, et al. Evidence for a continuum of genetic, phenotypic, and biochemical abnormalities in children with growth hormone insensitivity. Endocrine reviews. 2011;32(4):472-97.
  37. Ranke MB. Insulin-like growth factor binding-protein-3 (IGFBP–3). Best practice & research Clinical endocrinology & metabolism. 2015;29(5):701-11.
  38. Johnson MA, Firth SM. IGFBP-3: a cell fate pivot in cancer and disease. Growth Hormone & IGF Research. 2014;24(5):164-73.
  39. Russomando L, Bono V, Mancini A, Terracciano A, Cozzolino F, Imperlini E, et al. The Effects of Short-Term High-Intensity Interval Training and Moderate Intensity Continuous Training on Body Fat Percentage, Abdominal Circumference, BMI and VO2max in Overweight Subjects. Journal of Functional Morphology and Kinesiology. 2020;5(2):41.