1. Dolberg P, Ayalon L. Subjective meanings and identification with middle age. The International Journal of Aging and Human Development. 2018;87(1):52-76. doi.org/10.1177/0091415017721932.
2. Straight CR, Lindheimer JB, Brady AO, Dishman RK, Evans EM. Effects of resistance training on lower-extremity muscle power in middle-aged and older adults: a systematic review and meta-analysis of randomized controlled trials. Sports Medicine. 2016;46:353-64. doi:10.1007/s40279-015-0418-4.
3. Chodzko-Zajko WJ, Proctor DN, Singh MAF, Minson CT, Nigg CR, Salem GJ, et al. Exercise and physical activity for older adults. Medicine & science in sports & exercise. 2009;41(7):1510-30. doi:10.1249/MSS.0b013e3181a0c95c.
4. Borzuola R, Giombini A, Torre G, Campi S, Albo E, Bravi M, et al. Central and peripheral neuromuscular adaptations to ageing. Journal of clinical medicine. 2020;9(3):741. doi.org/10.3390/jcm9030741.
5. III LJM, Khosla S, Crowson CS, OConnor MK, OFallon WM, Riggs BL. Epidemiology of sarcopenia. Journal of the American Geriatrics Society. 2000;48(6):625-30. doi.org/10.1111/j.1532-5415.2000.tb04719.
6. Gomes MJ, Martinez PF, Pagan LU, Damatto RL, Cezar MDM, Lima ARR, et al. Skeletal muscle aging: influence of oxidative stress and physical exercise. Oncotarget. 2017;8(12):20428. doi:10.18632/oncotarget.14670.
7. Dickinson JM, Volpi E, Rasmussen BB. Exercise and nutrition to target protein synthesis impairments in aging skeletal muscle. Exercise and sport sciences reviews. 2013;41(4):216-23. doi:10.1097/JES.0b013e3182a4e699.
8. Konopka AR, Harber MP. Skeletal muscle hypertrophy after aerobic exercise training. Exercise and sport sciences reviews. 2014;42(2):53-61. doi:10.1249/JES.0000000000000007.
9. Cooper R, Strand BH, Hardy R, Patel KV, Kuh D. Physical capability in mid-life and survival over 13 years of follow-up: British birth cohort study. Bmj. 2014;348. doi.org/10.1136/bmj.g2219.
10. Straight CR, Brady AO, Evans EM. Muscle quality in older adults: what are the health implications? American Journal of Lifestyle Medicine. 2015;9(2):130-6. doi:org/10.1177/1559827613510681.
11. Cadore EL,Pinto RS, Alberton CL, Pinto SS, Lhullier FLR, Tartaruga MP, et al. Neuromuscular economy, strength, and endurance in healthy elderly men. The Journal of Strength & Conditioning Research 2011;25(4):997-1003. doi:10.1519/JSC.0b013e3181d650ba.
12. Gao J, Yu L. Effects of concurrent training sequence on VO2max and lower limb strength performance: A systematic review and meta-analysis. Frontiers in Physiology. 2023;14:1072679. doi.org/10.3389/fphys.2023.1072679.
13. Sadeghi H, Prince F, Zabjek KF, Allard P. Sagittal-hip-muscle power during walking in old and young able-bodied men. Journal of Aging and Physical Activity. 2001;9(2):172-83. doi:org/10.1123/japa.9.2.172.
14. Rankin JK, Woollacott MH, Shumway-Cook A, Brown LA. Cognitive influence on postural stability: a neuromuscular analysis in young and older adults. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences. 2000;55(3):M112-M9. doi.org/10.1093/gerona/55.3.M112.
15. Kachanathu SJ, Alenazi AM, Algarni AD, Hafez AR, Hameed UA, Nuhmani S, et al. Effect of forward and backward locomotion training on anaerobic performance and anthropometrical composition. Journal of physical therapy science. 2014;26(12):1879-82. doi:org/10.1589/jpts.26.1879.
16. Adesola A, Azeez O. Comparison of cardio-pulmonary responses to forward and backward walking and running. African Journal of Biomedical Research. 2009;12(2):95-100.
17. Cavagna G, Legramandi M, La Torre A. An analysis of the rebound of the body in backward human running. Journal of Experimental Biology. 2012;215(1):75-84. doi.org/10.1242/jeb.057562.
18. Swati K, Ashima C, Saurabh S. Efficacy of backward training on agility and quadriceps strength. Elixir Humam Physiol. 2012;53:11918-21. https://www.elixirpublishers.com
19. Uthoff A, Oliver J, Cronin J, Harrison C, Winwood P. A new direction to athletic performance: understanding the acute and longitudinal responses to backward running. Sports Medicine. 2018;48:1083-96. doi.org/10.1007/s40279-018-0877-5.
20. Wang J, Xu J, An R. Effectiveness of backward walking training on balance performance: A systematic review and meta-analysis. Gait & posture. 2019;68:466-75. doi:org/10.1016/j.gaitpost.2019.01.002.
21. Maritz CA, Pigman J, Gravare Silbernagel K, Crenshaw J. Effects of backward walking training on balance, mobility, and gait in community-dwelling older adults. Activities, Adaptation & Aging. 2021;45(3):202-16. doi:org/10.1080/01924788.2020.1757329.
22. Kachanathu SJ, Hafez AR, Zakaria AR. Efficacy of backward versus forward walking on hamstring strain rehabilitation. International journal of therapies and rehabilitation research. 2013;2(1):8. doi: 10.5455/ijtrr.00000017.
23. Su Z, Su Y, Wang D. Effect of combined aerobic exercises on the physical health of the elderly without exercise comprehensive review. International Neurourology Journal. 2024;28(1):515-29. doi: 10.5123/inj.2024.1.inj58.
24. Bai X, Soh KG, Omar Dev RD, Talib O, Xiao W, Soh KL, et al. Aerobic exercise combination intervention to improve physical performance among the elderly: a systematic review. Frontiers in Physiology. 2022;12:798068. doi:org/10.3389/fphys.2021.798068.
25. Roelants M, Delecluse C, Verschueren SM. Whole‐body‐vibration training increases knee‐extension strength and speed of movement in older women. Journal of the American Geriatrics Society. 2004;52(6):901-8. doi:org/10.1111/j.1532-5415.2004.52256.x.
26. Yan P, Luo J, Zhang T, Wang X, Zhang X, Zhang L, et al. Physical fitness effect of three backward walking exercises intervention in overweight male college students. International Journal of Science. 2015;2(3):1-7.
27. Palmer TB, Akehi K, Thiele RM, Smith DB, Thompson BJ. Reliability of panoramic ultrasound imaging in simultaneously examining muscle size and quality of the hamstring muscles in young, healthy males and females. Ultrasound in medicine & biology. 2015;41(3):675-84. doi.org/10.1016/j.ultrasmedbio.2014.10.011.
28. Pinto RS, Correa CS, Radaelli R, Cadore EL, Brown LE, Bottaro M. Short-term strength training improves muscle quality and functional capacity of elderly women. Age. 2014;36:365-72. doi: org/10.1007/s11357-013-9567-2.
29. Parraca JA, Olivares Sánchez-Toledo PR, Carbonell Baeza A, Aparicio García-Molina VA, Adsuar Sala JC, Gusi Fuertes N. Test-retest reliability of Biodex Balance SD on physically active old people. J Hum Sport Exer. 2011;6(2):444-451. doi: 10.4100/jhse.2011.62.25.
30. Markov A, Hauser L, Chaabene H. Effects of concurrent strength and endurance training on measures of physical fitness in healthy middle-aged and older adults: a systematic review with meta-analysis. Sports Medicine. 2023;53(2):437-55. https://doi.org/10.1007/s40279-022-01764-2.
31. Hakkinen K, Kallinen M, Izquierdo M, Jokelainen K, Lassila H, Malkia E, et al. Changes in agonist-antagonist EMG, muscle CSA, and force during strength training in middle-aged and older people. Journal of applied physiology. 1998;84(4):1341-9. doi.org/10.1152/jappl.1998.84.4.1341.
32. Aagaard P, Suetta C, Caserotti P, Magnusson SP, Kjaer M. Role of the nervous system in sarcopenia and muscle atrophy with aging: strength training as a countermeasure. Scandinavian journal of medicine & science in sports. 2010;20(1):49-64. doi.org/10.1111/j.1600-0838.2009.01084.x.
33. Basualto-Alarcon C, Jorquera G, Altamirano F, Jaimovich E, Estrada M. Testosterone signals through mTOR and androgen receptor to induce muscle hypertrophy. Medicine and science in sports and exercise. 2013;45(9):1712-20. doi.org/10.1249/mss.0b013e31828cf5f3.
34. Mikkola J, Rusko H, Izquierdo M, Gorostiaga E, Häkkinen K. Neuromuscular and cardiovascular adaptations during concurrent strength and endurance training in untrained men. International journal of sports medicine. 2012;33(09):702-10. dx.doi.org/ 10.1055/s-0031-1295475.
35. Wilhelm EN, Rech A, Minozzo F, Botton CE, Radaelli R, Teixeira BC, et al. Concurrent strength and endurance training exercise sequence does not affect neuromuscular adaptations in older men. Experimental gerontology 2014;60:207-14. doi.org/10.1016/j.exger.2014.11.007.
36. Cadore EL, Izquierdo M, Alberton CL, Pinto RS, Conceicao M, Cunha G, et al. Strength prior to endurance intra-session exercise sequence optimizes neuromuscular and cardiovascular gains in elderly men. Experimental gerontology. 2012;47(2):164-9. doi.org/10.1016/j.exger.2011.11.013.
37. Widodo AF, Tien C-W, Chen C-W, Lai S-C, Isotonic and isometric exercise interventions improve the hamstring muscles’ strength and flexibility: A narrative review. Healthcare; 2022: MDPI. doi.org/10.3390/healthcare10050811.
38. Whitley CR, Dufek JS. Effects of backward walking on hamstring flexibility and low back range of motion. International Journal of Exercise Science. 2011;4(3):4. doi.org/10.70252/CRZW7475.
39. Hao W-Y, Chen Y. Backward walking training improves balance in school-aged boys. Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology. 2011;3:1-7. doi.org/10.1186/1758-2555-3-24.
40. Lazarczuk SL, Collings TJ, Hams AH, Timmins RG, Shield AJ, Barrett RS, et al. Hamstring muscle‐tendon geometric adaptations to resistance training using the hip extension and nordic hamstring exercises. Scandinavian Journal of Medicine & Science in Sports. 2024;34(9):e14728. doi.org/10.1111/sms.14728.
41. Russ DW, Gregg-Cornell K, Conaway MJ, Clark BC. Evolving concepts on the age-related changes in “muscle quality”. Journal of cachexia, sarcopenia and muscle. 2012;3:95-109. doi.org/10.1007/s13539-011-0054-2.
42. Evangelidis PE, Massey GJ, Pain MT, Folland JP. Strength and size relationships of the quadriceps and hamstrings with special reference to reciprocal muscle balance. European journal of applied physiology. 2016;116:593-600. doi.org/10.1007/s00421-015-3321-7.
43. Lusa Cadore E, Pinto RS, Bottaro M, Izquierdo Redín M. Strength and endurance training prescription in healthy and frail elderly. Aging and Disease, 2014;5(3):183-195. doi.org/10.14336/AD.2014.0500183.
44. Rafique N, Nizami GN, Rafique A. Effectiveness of isotonic exercises on quadriceps-hamstring strangth ratio in osteoarthritic females. Pakistan Journal of Rehabilitation. 2013;2(2):15-20. doi.org/10.1152/jappl.1995.78.3.976.
45. Kraemer WJ, Patton JF, Gordon SE, Harman EA, Deschenes MR, Reynolds K, et al. Compatibility of high-intensity strength and endurance training on hormonal and skeletal muscle adaptations. Journal of applied physiology. 1995;78(3):976-89. doi.org/10.1152/jappl.1995.78.3.976.
46. Nader GA. Concurrent strength and endurance training: from molecules to man. Medicine and science in sports and exercise. 2006;38(11):1965. doi: 10.1249/01.mss.0000233795.39282.33.
47. Clary S, Barnes C, Bemben D, Knehans A, Bemben M. Effects of ballates, step aerobics, and walking on balance in women aged 50–75 years. Journal of sports science & medicine. 2006;5(3):390-399. https://www.jssm.org/vol5/n3/5/v5n3-5text.php.
48. Zhong S, Chen C, Thompson L. Sarcopenia of ageing: functional, structural and biochemical alterations. Brazilian journal of physical therapy. 2007;11:91-7. doi.org/10.1590/S1413-35552007000200002.
49. Lacroix A, Hortobagyi T, Beurskens R, Granacher U. Effects of supervised vs. unsupervised training programs on balance and muscle strength in older adults: a systematic review and meta-analysis. Sports medicine. 2017;47:2341-61. doi.org/10.1007/s40279-017-0747-6.
50. Dunsky A, Yahalom T, Arnon M, Lidor R. The use of step aerobics and the stability ball to improve balance and quality of life in community-dwelling older adults–a randomized exploratory study. Archives of gerontology and geriatrics. 2017;71:66-74. doi.org/10.1016/j.archger.2017.03.003.
51. Peters E, Pritzkuleit R, Beske F, Katalinic A. Demographic change and disease rates: a projection until 2050. Bundesgesundheitsblatt-Gesundheitsforschung-Gesundheitsschutz. 2010;53:417-26. doi.org/10.1007/s00103-010-1050-y.
52. Sousa N, Mendes R, Silva A, Oliveira J. Combined exercise is more effective than aerobic exercise in the improvement of fall risk factors: a randomized controlled trial in community-dwelling older men. Clinical rehabilitation. 2017;31(4):478-86. doi: 10.1177/0269215516655857. Epub 2016 Jul 10.
53. Canii U, Prieto-Gonzaiez P. Following changes in balance and cognitive performance on healthy middleaged people: Evaluation of the effect of two types of concurrent training. Human Movement.24(4):98-109. doi.org/10.5114/hm.2023.133923.
54. Silva JC, Brandão EM, Puga GM, Kanitz AC. The execution order of the concurrent training and its effects on static and dynamic balance, and muscle strength of elderly people. Motriz: Journal of Physical Education. 2022;28:e10220001922. doi: 10.1590/s1980-657420220001922.
55. Lentejas JPR, Sandoval MAS, Evangelista TJP, Buenaluz-Sedurante MD, Velayo CLL. The effect of resistance, aerobic, and concurrent aerobic and resistance exercises on inflammatory markers of metabolically healthy overweight or obese adults: A systematic review and meta-analysis. Acta Medica Philippina. 2023. doi.org/10.47895/amp.vi0.7315.
56. Laufer Y. Effect of age on characteristics of forward and backward gait at preferred and accelerated walking speed. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences. 2005;60(5):627-32. doi.org/10.1093/gerona/60.5.627.