Study aim: The purpose of this study was to evaluate neuromuscular adaptations in conscripts with different fitness levels (VO2max) during 8 weeks of military basic training (BT).
Material and methods: Twenty-four male conscripts (18–21 years) were divided into two groups (Good Fitness [GF] and Low fitness [LF]) based on their VO2max at the beginning of BT. Body mass (BM), fat free mass (FFM) and Fat% were measured after 2, 4, and 7 weeks of training. VO2max, maximal isometric leg press force (MVC), H-reflex (Hmax/Mmax) at rest and V-wave (V/Mmax) during maximal isometric plantarflexion were measured from the soleus muscle at the beginning, after 5, and after 8 weeks of training.
Results: FFM decreased significantly in LF after 7 weeks of training (–3.0 ± 1.7%, p < 0.001), which was not observed in GF. Both GF (6.9 ± 4.6%, p < 0.01) and LF (5.7 ± 4.6%, p < 0.01) showed improved VO2max after 5 weeks, with no changes during the last 3 weeks. A main effect of training was observed in decreased leg press MVC (–7.3 ± 9.3%, F = 4.899, p < 0.05), with no between-group differences. V-wave was significantly lower in LF during 5 (–37.9%, p < 0.05) and 8 (–44.9%, p < 0.05) weeks.
Conclusion: Poor development of the neuromuscular system during BT suggests that explosive and/or maximal strength training should be added to the BT protocol for all conscripts regardless of fitness level. In addition, individualized training periodization should be considered to optimize the training load.
If the inline PDF is not rendering correctly, you can download the PDF file here.
1. Aagaard P. Simonsen E.B. Andersen J.L. Magnusson P. Dyhre-Poulsen P. (2002) Neural adaptation to resistance training: changes in evoked V-wave and H-reflex responses. J. Appl. Physiol. 92: 2309-2318.
2. Anderson L.J. Erceg D.N. Schroeder E.T. (2012) Utility of multifrequency bioelectrical impedance compared with dual-energy x-ray absorptiometry for assessment of total and regional body composition varies between men and women. Nutr. Res. (New York NY) 32: 479-485.
3. Buchthal F. Schmalbruch H. (1970) Contraction times of twitches evoked by H-reflexes. Acta Physiol. Scand. 80: 378-382.
4. Glowacki S.P. Martin S.E. Maurer A. Baek W. Green J.S. Crouse S.F. (2004) Effects of resistance endurance and concurrent exercise on training outcomes in men. Med. Sci. Sports Exerc. 36: 2119-2127.
5. Hakkinen K. Alen M. Kraemer W.J. Gorostiaga E. Izquierdo M. Rusko H. Mikkola J. Hakkinen A. Valkeinen H. Kaarakainen E. Romu S. Erola V. Ahtiainen J. Paavolainen L. (2003) Neuromuscular adaptations during concurrent strength and endurance training versus strength training. Eur. J. Appl. Physiol. 89: 42-52.
6. Hermens H.J. Freriks B. Merletti R. Stegeman D. Blok J. Rau G. Disselhorst-Klug C. Hägg G. (1999) European recommendations for surface electromyography : results of the SENIAM project. Enschede: Roessingh Research and Development.
7. Kinnunen J.V. Piitulainen H. Piirainen J.M. (2019) Neuromuscular adaptations to short-term high-intensity interval training in female ice hockey players. J. Strength Cond. Res. 33(2):479-485. DOI: 10.1519/JSC.0000000000001881.
8. Kraemer W.J. Patton J.F. Gordon S.E. Harman E.A. Deschenes M.R. Reynolds K. Newton R.U. Triplett N.T. Dziados J.E. (1995) Compatibility of high-intensity strength and endurance training on hormonal and skeletal muscle adaptations. J. Appl. Physiol. (Bethesda Md : 1985) 78: 976-989.
9. Kyröläinen H. Komi P.V. (1994) Neuromuscular performance of lower limbs during voluntary and reflex activity in power – and endurance-trained athletes. Eur. J. Appl. Physiol. and Occup. Physiol. 69: 233-239.
10. Kyröläinen H. Santtila M. Nindl B.C. Vasankari T. (2010) Physical fitness profiles of young men: associations between physical fitness obesity and health. Sports Med. (Auckland NZ) 40: 907-920.
11. Leyk D. Rohde U. Gorges W. Ridder D. Wunderlich M. Dinklage C. Sievert A. Ruther T. Essfeld D. (2006) Physical performance body weight and BMI of young adults in Germany 2000–2004: results of the physical-fitness-test study. Int. J. Sports Med. 27: 642-647.
12. Maffiuletti N.A. Martin A. Babault N. Pensini M. Lucas B. Schieppati M. (2001) Electrical and mechanical H(max)-to-M(max) ratio in power – and endurance-trained athletes. J. Appl. Physiol. 90: 3-9.
13. Mikkola J. Rusko H. Izquierdo M. Gorostiaga E.M. Hakkinen K. (2012) Neuromuscular and cardiovascular adaptations during concurrent strength and endurance training in untrained men. Int. J. Sports Med. 33: 702-710.
14. Mikkola J. Rusko H. Nummela A. Pollari T. Hakkinen K. (2007) Concurrent endurance and explosive type strength training improves neuromuscular and anaerobic characteristics in young distance runners. Int. J. Sports Med. 28: 602-611.
15. Mikkola J.S. Rusko H.K. Nummela A.T. Paavolainen L.M. Hakkinen K. (2007) Concurrent endurance and explosive type strength training increases activation and fast force production of leg extensor muscles in endurance athletes. J. Strength Cond. Res. 21: 613-620.
16. Misiaszek J.E. (2003) The H-reflex as a tool in neuro-physiology: its limitations and uses in understanding nervous system function. Muscle Nerve 28: 144-160.
17. Moritani T. deVries H.A. (1979) Neural factors versus hypertrophy in the time course of muscle strength gain. Am. J. Phys. Med. 58: 115-130.
18. Palmieri R.M. Ingersoll C.D. Hoffman M.A. (2004) The Hoffmann Reflex: Methodologic Considerations and Applications for Use in Sports Medicine and Athletic Training Research. J. Athl. Train. 39: 268-277.
19. Pasiakos S.M. Margolis L.M. (2017) Negative energy balance and loss of body mass and fat-free mass in military personnel subsisting on combat rations during training and combat operations: a comment on Tassone and Baker. Br. J. Nutr. 117: 894-896.
20. Piirainen J.M. Salmi J.A. Avela J. Linnamo V. (2008) Effect of body composition on the neuromuscular function of Finnish conscripts during an 8-week basic training period. J. Strength Cond. Res. 22: 1916-1925.
21. Psilander N. Frank P. Flockhart M. Sahlin K. (2015) Adding strength to endurance training does not enhance aerobic capacity in cyclists. Scand. J. Med. Sci. Sports 25: e353-359.
22. Raglin J.S. Koceja D.M. Stager J.M. Harms C.A. (1996) Mood neuromuscular function and performance during training in female swimmers. Med. Sci. Sports Exerc. 28: 372-377.
23. Roitman J.L. Herridge M. (2001) ACSM`s resource manual for Guidelines for exercise testing and prescription. Lippincott Williams & Wilkins.
24. Santtila M. Häkkinen K. Karavirta L. Kyröläinen H. (2008) Changes in cardiovascular performance during an 8-week military basic training period combined with added endurance or strength training. Mil. Med. 117: 1173-1179.
25. Santtila M. Kyröläinen H. Hakkinen K. (2009) Changes in maximal and explosive strength electromyography and muscle thickness of lower and upper extremities induced by combined strength and endurance training in soldiers. J. Strength Cond. Res. 23: 1300-1308.
26. Santtila M. Kyröläinen H. Vasankari T. Tiainen S. Palvalin K. Hakkinen A. Hakkinen K. (2006) Physical fitness profiles in young Finnish men during the years 1975–2004. Med. Sci. Sports Exerc. 38: 1990-1994.
27. Shvartz E. Reibold R.C. (1990) Aerobic fitness norms for males and females aged 6 to 75 years: a review. Aviat. Space Environ. Med. 61: 3-11.
28. Tanskanen M. Uusitalo A.L. Hakkinen K. Nissila J. Santtila M. Westerterp K.R. Kyröläinen H. (2009) Aerobic fitness energy balance and body mass index are associated with training load assessed by activity energy expenditure. Scand. J. Med. Sci. Sports 19: 871-878.
29. Tanskanen M.M. Kyröläinen H. Uusitalo A.L. Huovinen J. Nissila J. Kinnunen H. Atalay M. Hakkinen K. (2011) Serum sex hormone-binding globulin and cortisol concentrations are associated with overreaching during strenuous military training. J. Strength Cond. Res. 25: 787-797.
30. Tanskanen M.M. Uusitalo A.L. Kinnunen H. Hakkinen K. Kyröläinen H. Atalay M. (2011) Association of military training with oxidative stress and overreaching. Med. Sci. Sports Exerc. 43: 1552-1560.
31. Upton A.R. McComas A.J. Sica R.E.(1971) Potentiation of “late” responses evoked in muscles during effort. J. Neurol. Neurosurg. Psychiatry 34: 699-711.
32. Vila-Cha C. Falla D. Correia M.V. Farina D. (2012) Changes in H reflex and V wave following short-term endurance and strength training. J. Appl. Physiol. (1985) 112: 54-63.
33. Williams A.G. (2005) Effects of basic training in the British Army on regular and reserve army personnel. J. Strength Cond. Res. 19: 254-259.