Exercise induced changes in echo intensity within the muscle: a brief review

  • Vickie Wong
  • Robert W. Spitz
  • Zachary W. Bell
  • Ricardo B. Viana
  • Raksha N. Chatakondi
  • Takashi Abe
  • Jeremy P. LoennekeEmail author
Review Paper


Echo intensity is the mean pixel intensity of a specific region of interest from an ultrasound image. This variable has been increasingly used in the literature as a physiological marker. Although there has been an increased interest in reporting changes in echo intensity in response to exercise, little consensus exists as to what a change in echo intensity represents physiologically. The purpose of this paper is to review some of the earliest, as well as the most up to date literature regarding the changes in echo intensity in response to exercise. Echo intensity has been used to measure muscle quality, muscle damage, acute swelling, and intramuscular glycogen. The changes in echo intensity, however, are not consistent throughout the literature and often times lead to conclusions that seem contrary to the physiologic effects of exercise. For example, echo intensity increases in conjunction with increases in strength, contrary to what would be expected if echo intensity was a marker of muscle quality/muscle damage. It is conceivable that a change in echo intensity represents a range of physiologic effects at different time points. We recommend that these effects should be determined experimentally in order to rule out what echo intensity might and might not represent. Until this is done, caution should be employed when interpreting changes in echo intensity with acute and chronic exercise.


Muscle quality Edema Muscle damage Glycogen content Fluid shift Muscle swelling Ultrasound Intracellular Exercise 


Compliance with ethical standards

Conflict of interest

The authors declare they have no conflict of interest.

Ethical approval

This article does not contain any studies with human participants or animals performed by any of the authors.


  1. 1.
    Yasuda T, Loenneke JP, Thiebaud RS, Abe T (2012) Effects of blood flow restricted low-intensity concentric or eccentric training on muscle size and strength. PLoS ONE 7:e52843. CrossRefPubMedPubMedCentralGoogle Scholar
  2. 2.
    Schedel H, Reimers CD, Nägele M et al (1992) Imaging techniques in myotonic dystrophy. A comparative study of ultrasound, computed tomography and magnetic resonance imaging of skeletal muscles. Eur J Radiol 15:230–238. CrossRefPubMedGoogle Scholar
  3. 3.
    Medeiros DM, Mantovani RF, Lima CS (2017) Effects of low-intensity pulsed ultrasound on muscle thickness and echo intensity of the elbow flexors following exercise-induced muscle damage. Sport Sci Health 13:365–371. CrossRefGoogle Scholar
  4. 4.
    Wong V, Abe T, Chatakondi RN et al (2019) The influence of biological sex and cuff width on muscle swelling, echo intensity, and the fatigue response to blood flow restricted exercise. J Sports Sci 37:1865–1873CrossRefGoogle Scholar
  5. 5.
    Franchi MV, Longo S, Mallinson J et al (2018) Muscle thickness correlates to muscle cross-sectional area in the assessment of strength training-induced hypertrophy. Scand J Med Sci Sports 28:846–853. CrossRefPubMedGoogle Scholar
  6. 6.
    Loenneke JP, Dankel SJ, Bell ZW et al (2019) Ultrasound and MRI measured changes in muscle mass gives different estimates but similar conclusions: a Bayesian approach. Eur J Clin Nutr. CrossRefPubMedGoogle Scholar
  7. 7.
    Yoshiko A, Tomita A, Ando R et al (2018) Effects of 10-week walking and walking with home-based resistance training on muscle quality, muscle size, and physical functional tests in healthy older individuals. Eur Rev Aging Phys Act 15:13. CrossRefPubMedPubMedCentralGoogle Scholar
  8. 8.
    Yoshiko A, Kaji T, Sugiyama H et al (2019) Twenty-four months’ resistance and endurance training improves muscle size and physical functions but not muscle quality in older adults requiring long-term care. J Nutr Health Aging 23:564–570. CrossRefPubMedGoogle Scholar
  9. 9.
    Blue MNM, Smith-Ryan AE, Trexler ET, Hirsch KR (2018) The effects of high intensity interval training on muscle size and quality in overweight and obese adults. J Sci Med Sport 21:207–212. CrossRefPubMedGoogle Scholar
  10. 10.
    de Bassan N, Denadai BS, de Lima LCR et al (2019) Effects of resistance training on impulse above end-test torque and muscle fatigue. Exp Physiol 104:1115–1125. CrossRefGoogle Scholar
  11. 11.
    Varghese A, Bianchi S (2014) Ultrasound of tibialis anterior muscle and tendon: anatomy, technique of examination, normal and pathologic appearance. J Ultrasound 17:113–123. CrossRefPubMedGoogle Scholar
  12. 12.
    Nosaka K, Clarkson PM (1996) Changes in indicators of inflammation after eccentric exercise of the elbow flexors. Med Sci Sports Exerc 28:953–961. CrossRefPubMedGoogle Scholar
  13. 13.
    Sipila S, Suominen H (1991) Ultrasound imaging of the quadriceps muscle in elderly athletes and untrained men. Muscle Nerve 14:527–533. CrossRefPubMedGoogle Scholar
  14. 14.
    Nieman DC, Shanely RA, Zwetsloot KA et al (2015) Ultrasonic assessment of exercise-induced change in skeletal muscle glycogen content. BMC Sports Sci Med Rehabil 7:9. CrossRefPubMedPubMedCentralGoogle Scholar
  15. 15.
    Yitzchaki N, Kuehne TE, Mouser JG, Buckner SL (2019) Can changes in echo intensity be used to detect the presence of acute muscle swelling? Physiol Meas 40:045002. CrossRefPubMedGoogle Scholar
  16. 16.
    Hill J, San Millán I (2014) Validation of musculoskeletal ultrasound to assess and quantify muscle glycogen content. A novel approach. Physician Sportsmed 42:45–52. CrossRefGoogle Scholar
  17. 17.
    Routledge HE, Bradley WJ, Shepherd SO et al (2019) Ultrasound does not detect acute changes in glycogen in vastus lateralis of man. Med Sci Sports Exerc. CrossRefPubMedGoogle Scholar
  18. 18.
    Muddle TWD, Magrini MA, Colquhoun RJ et al (2019) Impact of fatiguing, submaximal high-vs. low-torque isometric exercise on acute muscle swelling, and echo intensity in resistance-trained men. J Strength 33:1007–1019. CrossRefGoogle Scholar
  19. 19.
    Chen TC, Nosaka K (2006) Responses of elbow flexors to two strenuous eccentric exercise bouts separated by three days. J Strength Cond Res 20:108PubMedGoogle Scholar
  20. 20.
    Cadore EL, González-Izal M, Pallarés JG et al (2014) Muscle conduction velocity, strength, neural activity, and morphological changes after eccentric and concentric training. Scand J Med Sci Sports 24:e343–e352. CrossRefPubMedGoogle Scholar
  21. 21.
    Yamada M, Kimura Y, Ishiyama D et al (2019) Synergistic effect of bodyweight resistance exercise and protein supplementation on skeletal muscle in sarcopenic or dynapenic older adults. Geriatr Gerontol Int 19:429–437. CrossRefPubMedGoogle Scholar
  22. 22.
    Jajtner A, Hoffman J, Scanlon T et al (2013) Performance and muscle architecture comparisons between starters and nonstarters in National Collegiate Athletic Association Division I women’s soccer. J Strength Cond Res 27:2355–2365. CrossRefPubMedGoogle Scholar
  23. 23.
    Radaelli R, Botton CE, Wilhelm EN et al (2013) Low- and high-volume strength training induces similar neuromuscular improvements in muscle quality in elderly women. Exp Gerontol 48:710–716. CrossRefPubMedGoogle Scholar
  24. 24.
    Radaelli R, Botton CE, Wilhelm EN et al (2014) Time course of low- and high-volume strength training on neuromuscular adaptations and muscle quality in older women. Age 36:881–892. CrossRefPubMedPubMedCentralGoogle Scholar
  25. 25.
    Mangine G, Redd MJ, Gonzalez AM et al (2018) Resistance training does not induce uniform adaptations to quadriceps muscles. Cold Spring Harbor. CrossRefGoogle Scholar
  26. 26.
    Yoshiko A, Kaji T, Sugiyama H et al (2017) Effect of 12-month resistance and endurance training on quality, quantity, and function of skeletal muscle in older adults requiring long-term care. Exp Gerontol 98:230–237. CrossRefPubMedGoogle Scholar
  27. 27.
    Santos R, Valamatos MJ, Mil-Homens P, Armada-da-Silva PAS (2018) Muscle thickness and echo-intensity changes of the quadriceps femoris muscle during a strength training program. Radiography 24:e75–e84. CrossRefPubMedGoogle Scholar
  28. 28.
    Chen TC, Chen H-L, Lin M-J et al (2009) Muscle damage responses of the elbow flexors to four maximal eccentric exercise bouts performed every 4 weeks. Eur J Appl Physiol 106:267–275. CrossRefPubMedGoogle Scholar
  29. 29.
    Chen T, Chen H-L, Lin M-J et al (2010) Potent protective effect conferred by four bouts of low-intensity eccentric exercise. Med Sci Sports Exerc 42:1004–1012. CrossRefPubMedGoogle Scholar
  30. 30.
    Chen TC, Lin K-Y, Chen H-L et al (2011) Comparison in eccentric exercise-induced muscle damage among four limb muscles. Eur J Appl Physiol 111:211–223. CrossRefPubMedGoogle Scholar
  31. 31.
    Radaelli R, Bottaro M, Wilhelm E et al (2012) Time course of strength and echo intensity recovery after resistance exercise in women. J Strength Cond Res 26:2577–2584. CrossRefPubMedGoogle Scholar
  32. 32.
    Chen TC, Tseng W-C, Huang G-L et al (2013) Low-intensity eccentric contractions attenuate muscle damage induced by subsequent maximal eccentric exercise of the knee extensors in the elderly. Eur J Appl Physiol 113:1005–1015. CrossRefPubMedGoogle Scholar
  33. 33.
    Gonzalez-Izal M, Cadore EL, Izquierdo M (2014) Muscle conduction velocity, surface electromyography variables, and echo intensity during concentric and eccentric fatigue. Muscle Nerve 49:389–397. CrossRefPubMedGoogle Scholar
  34. 34.
    Damas F, Phillips SM, Lixandrão ME et al (2016) Early resistance training-induced increases in muscle cross-sectional area are concomitant with edema-induced muscle swelling. Eur J Appl Physiol 116:49–56. CrossRefPubMedGoogle Scholar
  35. 35.
    Jenkins NDM, Housh TJ, Buckner SL et al (2016) Neuromuscular adaptations after 2 and 4 weeks of 80% versus 30% 1 repetition maximum resistance training to failure. J Strength Cond Res 30:2174–2185. CrossRefPubMedGoogle Scholar
  36. 36.
    Fritsch CG, Dornelles MP, Severo-Silveira L et al (2016) Effects of low-level laser therapy applied before or after plyometric exercise on muscle damage markers: randomized, double-blind, placebo-controlled trial. Lasers Med Sci 31:1935–1942. CrossRefPubMedGoogle Scholar
  37. 37.
    Stock MS, Mota JA, DeFranco RN et al (2017) The time course of short-term hypertrophy in the absence of eccentric muscle damage. Eur J Appl Physiol 117:989–1004. CrossRefPubMedGoogle Scholar
  38. 38.
    Grazioli R, Lopez P, Machado CLF et al (2019) Moderate volume of sprint bouts does not induce muscle damage in well-trained athletes. J Bodyw Mov Ther. CrossRefGoogle Scholar
  39. 39.
    Brusco CM, Blazevich AJ, Radaelli R et al (2018) The effects of flexibility training on exercise-induced muscle damage in young men with limited hamstrings flexibility. Scand J Med Sci Sports 28:1671–1680. CrossRefPubMedGoogle Scholar
  40. 40.
    da Matta TT, de Pereira WCA, Radaelli R et al (2018) Texture analysis of ultrasound images is a sensitive method to follow-up muscle damage induced by eccentric exercise. Clin Physiol Funct Imaging 38:477–482. CrossRefPubMedGoogle Scholar
  41. 41.
    Matta TT, Pinto RO, Leitão BFM, Oliveira LF (2019) Non-uniformity of elbow flexors damage induced by an eccentric protocol in untrained men. J Sports Sci Med 18:223–228PubMedPubMedCentralGoogle Scholar
  42. 42.
    Tsuchiya Y, Yanagimoto K, Ueda H, Ochi E (2019) Supplementation of eicosapentaenoic acid-rich fish oil attenuates muscle stiffness after eccentric contractions of human elbow flexors. J Int Soc Sports Nutr 16:19. CrossRefPubMedPubMedCentralGoogle Scholar
  43. 43.
    Biazon TMPC, Ugrinowitsch C, Soligon SD et al (2019) The association between muscle deoxygenation and muscle hypertrophy to blood flow restricted training performed at high and low loads. Front Physiol. CrossRefPubMedPubMedCentralGoogle Scholar
  44. 44.
    Cadore EL, González-Izal M, Grazioli R et al (2019) Effects of concentric and eccentric strength training on fatigue induced by concentric and eccentric exercises. Int J Sports Physiol Perform 14:91–98. CrossRefGoogle Scholar
  45. 45.
    Botton CE, Umpierre D, Rech A et al (2018) Effects of resistance training on neuromuscular parameters in elderly with type 2 diabetes mellitus: a randomized clinical trial. Exp Gerontol 113:141–149. CrossRefPubMedGoogle Scholar
  46. 46.
    Fukumoto Y, Tateuchi H, Ikezoe T et al (2014) Effects of high-velocity resistance training on muscle function, muscle properties, and physical performance in individuals with hip osteoarthritis: a randomized controlled trial. Clin Rehabil 28:48–58. CrossRefPubMedGoogle Scholar
  47. 47.
    Fukumoto Y, Ikezoe T, Yamada Y et al (2012) Skeletal muscle quality assessed from echo intensity is associated with muscle strength of middle-aged and elderly persons. Eur J Appl Physiol 112:1519–1525. CrossRefPubMedGoogle Scholar
  48. 48.
    da Orssatto LBR, Detanico D, Kons RL et al (2019) Photobiomodulation therapy does not attenuate fatigue and muscle damage in judo athletes: a randomized, triple-blind, placebo-controlled trial. Front Physiol. CrossRefPubMedPubMedCentralGoogle Scholar
  49. 49.
    Chen T, Chen H-L, Lin M-J et al (2016) Contralateral repeated bout effect of eccentric exercise of the elbow flexors. Med Sci Sports Exerc 48:2030–2039. CrossRefPubMedGoogle Scholar
  50. 50.
    Lau WY, Blazevich AJ, Newton MJ et al (2015) Reduced muscle lengthening during eccentric contractions as a mechanism underpinning the repeated-bout effect. Am J Physiol Regul Integr Comp Physiol 308:R879–R886. CrossRefPubMedPubMedCentralGoogle Scholar
  51. 51.
    Nosaka K, Newton M, Sacco P et al (2005) Partial protection against muscle damage by eccentric actions at short muscle lengths. Med Sci Sports Exerc 37:746–753. CrossRefPubMedGoogle Scholar
  52. 52.
    Nosaka K, Sakamoto K (2001) Effect of elbow joint angle on the magnitude of muscle damage to the elbow flexors. Med Sci Sports Exerc 33:22CrossRefGoogle Scholar
  53. 53.
    Radaelli R, Bottaro M, Wagner DR et al (2014) Men and women experience similar muscle damage after traditional resistance training protocol. IES 22:47–54. CrossRefGoogle Scholar
  54. 54.
    Pereira MC, Bottaro M, Brown LE et al (2014) Do compression sleeves worn during exercise affect muscle recovery? Isokinet Exerc Sci 22:265–271. CrossRefGoogle Scholar
  55. 55.
    Chen H-L, Nosaka K, Chen TC (2012) Muscle damage protection by low-intensity eccentric contractions remains for 2 weeks but not 3 weeks. Eur J Appl Physiol 112:555–565CrossRefGoogle Scholar
  56. 56.
    Hill EC, Housh TJ, Keller JL et al (2018) Early phase adaptations in muscle strength and hypertrophy as a result of low-intensity blood flow restriction resistance training. Eur J Appl Physiol 118:1831–1843. CrossRefPubMedGoogle Scholar
  57. 57.
    Rowe GS, Blazevich AJ, Haff GG (2019) pQCT- and ultrasound-based muscle and fat estimate errors after resistance exercise. Med Sci Sports Exerc 51:1022–1031. CrossRefPubMedGoogle Scholar
  58. 58.
    Jenkins NDM, Miramonti AA, Hill EC et al (2017) Greater neural adaptations following high- vs. low-load resistance training. Front Physiol. CrossRefPubMedPubMedCentralGoogle Scholar
  59. 59.
    Lynch NA, Metter EJ, Lindle RS et al (1999) Muscle quality. I. Age-associated differences between arm and leg muscle groups. J Appl Physiol 86:188–194. CrossRefPubMedGoogle Scholar
  60. 60.
    McGregor RA, Cameron-Smith D, Poppitt SD (2014) It is not just muscle mass: a review of muscle quality, composition and metabolism during ageing as determinants of muscle function and mobility in later life. Longev Healthspan. CrossRefPubMedPubMedCentralGoogle Scholar
  61. 61.
    Goodpaster BH, Carlson CL, Visser M et al (2001) Attenuation of skeletal muscle and strength in the elderly: the Health ABC Study. J Appl Physiol 90:2157–2165. CrossRefPubMedGoogle Scholar
  62. 62.
    Heckmatt JZ, Leeman S, Dubowitz V (1982) Ultrasound imaging in the diagnosis of muscle disease. J Pediatr 101:656–660. CrossRefPubMedGoogle Scholar
  63. 63.
    Overend TJ, Cunningham DA, Paterson DH, Lefcoe MS (1992) Thigh composition in young and elderly men determined by computed tomography. Clin Physiol 12:629–640CrossRefGoogle Scholar
  64. 64.
    Scanlon TC, Fragala MS, Stout JR et al (2014) Muscle architecture and strength: adaptations to short-term resistance training in older adults: muscle adaptations. Muscle Nerve 49:584–592. CrossRefPubMedGoogle Scholar
  65. 65.
    Reimers K, Reimers CD, Wagner S et al (1993) Skeletal muscle sonography: a correlative study of echogenicity and morphology. J Ultrasound Med 12:73–77. CrossRefPubMedGoogle Scholar
  66. 66.
    Spiegler AWJ, Schindler S, Herrmann FH (1985) Becker muscular dystrophy: carrier detection by real-time ultrasound. J Neurol 232:307–309. CrossRefPubMedGoogle Scholar
  67. 67.
    Pillen S, Tak RO, Zwarts MJ et al (2009) Skeletal muscle ultrasound: correlation between fibrous tissue and echo intensity. Ultrasound Med Biol 35:443–446. CrossRefPubMedGoogle Scholar
  68. 68.
    Chen TC, Chen H-L, Lin M-J et al (2013) Effect of two maximal isometric contractions on eccentric exercise-induced muscle damage of the elbow flexors. Eur J Appl Physiol 113:1545–1554. CrossRefPubMedGoogle Scholar
  69. 69.
    Tseng K-W, Tseng W-C, Lin M-J et al (2016) Protective effect by maximal isometric contractions against maximal eccentric exercise-induced muscle damage of the knee extensors. Res Sports Med 24:228–241. CrossRefGoogle Scholar
  70. 70.
    Fujikake T, Hart R, Nosaka K (2009) Changes in B-mode ultrasound echo intensity following injection of bupivacaine hydrochloride to rat hind limb muscles in relation to histologic changes. Ultrasound Med Biol 35:687–696. CrossRefPubMedGoogle Scholar
  71. 71.
    Chen L, Nelson DR, Zhao Y et al (2013) Relationship between muscle mass and muscle strength, and the impact of comorbidities: a population-based, cross-sectional study of older adults in the United States. BMC Geriatr 13:74. CrossRefPubMedPubMedCentralGoogle Scholar
  72. 72.
    Loenneke JP, Thiebaud RS, Abe T (2014) Does blood flow restriction result in skeletal muscle damage? A critical review of available evidence. Scand J Med Sci Sports 24:e415–e422. CrossRefPubMedGoogle Scholar
  73. 73.
    Loenneke JP, Fahs CA, Rossow LM et al (2012) The anabolic benefits of venous blood flow restriction training may be induced by muscle cell swelling. Med Hypotheses 78:151–154. CrossRefPubMedGoogle Scholar
  74. 74.
    Loenneke JP, Fahs CA, Thiebaud RS et al (2012) The acute muscle swelling effects of blood flow restriction. Acta Physiol Hung 99:400–410. CrossRefPubMedGoogle Scholar
  75. 75.
    Kim D, Loenneke JP, Ye X et al (2017) Low-load resistance training with low relative pressure produces muscular changes similar to high-load resistance training. Muscle Nerve 56:E126–E133. CrossRefPubMedGoogle Scholar
  76. 76.
    Cumming KT, Paulsen G, Wernbom M et al (2014) Acute response and subcellular movement of HSP27, αB-crystallin and HSP70 in human skeletal muscle after blood-flow-restricted low-load resistance exercise. Acta Physiol 211:634–646. CrossRefGoogle Scholar
  77. 77.
    Dankel SJ, Abe T, Spitz RW et al. (2019) Impact of acute fluid retention on ultrasound echo intensity. J Clin Densitom. CrossRefPubMedGoogle Scholar
  78. 78.
    Dankel SJ, Abe T, Bell ZW et al (2018) The impact of ultrasound probe tilt on muscle thickness and echo-intensity: a cross-sectional study. J Clin Densitom. CrossRefPubMedGoogle Scholar
  79. 79.
    Rabello R, Fröhlich M, Bueno AF et al (2019) Echo intensity reliability between two rectus femoris probe sites. Ultrasound. CrossRefPubMedGoogle Scholar
  80. 80.
    Martín-Hernández J, Marín P, Menéndez H et al (2013) Changes in muscle architecture induced by low load blood flow restricted training. Acta Physiol Hung. CrossRefPubMedGoogle Scholar
  81. 81.
    Kenny GP, Reardon FD, Zaleski W et al (2003) Muscle temperature transients before, during, and after exercise measured using an intramuscular multisensor probe. J Appl Physiol 94:2350–2357. CrossRefPubMedGoogle Scholar

Copyright information

© Società Italiana di Ultrasonologia in Medicina e Biologia (SIUMB) 2020

Authors and Affiliations

  • Vickie Wong
    • 1
  • Robert W. Spitz
    • 1
  • Zachary W. Bell
    • 1
  • Ricardo B. Viana
    • 1
    • 2
  • Raksha N. Chatakondi
    • 1
  • Takashi Abe
    • 1
  • Jeremy P. Loenneke
    • 1
    Email author
  1. 1.Kevser Ermin Applied Physiology Laboratory, Department of Health, Exercise Science, and Recreation ManagementThe University of MississippiUniversityUSA
  2. 2.Faculty of Physical Education and DanceFederal University of GoiásGoiâniaBrazil

Personalised recommendations