Effects of a 12-week time-of-day-specific concurrent resistance-aerobic training on muscle strength, bone mass and functional performance in elderly women

Diurnal strength fluctuations and the effects of time-of-day-specific training are well-documented in young adults but unclear in elderly women. This study investigated the effects of time-of-day-specific concurrent resistance-aerobic training on muscle strength, bone mass, and functional performance in elderly women. Twenty-six women (65-85 years) were randomized into morning (MTG), afternoon (ATG) and control (CON) groups. Training groups completed 12 weeks of concurrent resistance-aerobic training (3 sessions/week, factor of time). Outcomes included maximal knee extension torque (measured AM/PM, factor of test time), bone mineral density (DXA), and functional tests (30-s chair stand, Five Times Sit-to-Stand and Maximal gait speed). Analysis of strength confirmed a preserved diurnal rhythm, with morning performance deficit present (test time: p=0.0129). The group and time factors interaction approached significance (p=0.0624), further test showed that only ATG differed significantly from the CON, with broader improvement than MTG. The functional performance significantly improved in all tests (p<0.0001, p=0.0002, p=0.0200, respectively) compared to baseline, with no difference between groups. The bone mass parameters remained unchanged. The time-of-day-specific concurrent training improved strength and functional performance in both training groups with afternoon training producing superior strength gains compared to morning training. Unchanged bone parameters suggest longer interventions might be needed for osteogenic effects.

1. Lazarus NR, Harridge SDR. The Inherent Human Aging Process and the Facilitating Role of Exercise. Front Physiol 2018;9:1135. DOI: https://doi.org/10.3389/fphys.2018.01135

2. Hernandez-Martinez J, Branco BHM, Vasquez-Carrasco E, et al. Effects of strength training on body composition, physical performance, and protein or calcium intake in older people with osteosarcopenia: a meta-analysis. Nutrients 2025;17:2852. DOI: https://doi.org/10.3390/nu17172852

3. Izquierdo M, Merchant RA, Morley JE, et al. International Exercise Recommendations in Older Adults (ICFSR): Expert Consensus Guidelines. J Nutr Health Aging 2021;25:824–53. DOI: https://doi.org/10.1007/s12603-021-1665-8

4. Ma J, Wen J, Qiu Y, et al. The regional impact of exercise on bone density in older adults: a meta-analysis with molecular mechanism insights. Geriatr Nurs (Minneap) 2025;65:103451. DOI: https://doi.org/10.1016/j.gerinurse.2025.103451

5. Kerschan-Schindl K, Hasenoehrl T. Exercise in the Prevention of Age-Related Fragility Fractures (Narrative Review). Gerontology 2025;71:173–84. DOI: https://doi.org/10.1159/000543377

6. Wright VJ, Schwartzman JD, Itinoche R, Wittstein J. The musculoskeletal syndrome of menopause. Climacteric 2024;27:466–72. DOI: https://doi.org/10.1080/13697137.2024.2380363

7. Khadilkar SS. Musculoskeletal disorders and menopause. J Obstet Gynecol India 2019;69:99–103. DOI: https://doi.org/10.1007/s13224-019-01213-7

8. Wang Z, Zan X, Li Y, et al. Comparative efficacy different resistance training protocols on bone mineral density in postmenopausal women: A systematic review and network meta-analysis. Front Physiol 2023;14:1105303. DOI: https://doi.org/10.3389/fphys.2023.1105303

9. Zhao F, Su W, Sun Y, et al. Optimal resistance training parameters for improving bone mineral density in postmenopausal women: a systematic review and meta-analysis. J Orthop Surg Res 2025;20:523. DOI: https://doi.org/10.1186/s13018-025-05890-1

10. Zhao R, Zhang M, Zhang Q. The effectiveness of combined exercise interventions for preventing postmenopausal bone loss: a systematic review and meta-analysis. J Orthopaedic Sports Physical Ther 2017;47:241–51. DOI: https://doi.org/10.2519/jospt.2017.6969

11. Basti A, Yalçin M, Herms D, et al. Diurnal variations in the expression of core-clock genes correlate with resting muscle properties and predict fluctuations in exercise performance across the day. BMJ Open Sport Exerc Med 2021;7:e000876. DOI: https://doi.org/10.1136/bmjsem-2020-000876

12. Sedliak M, Zeman M, Buzgó G, et al. Morphological, molecular and hormonal adaptations to early morning versus afternoon resistance training. Chronobiol Int 2018;35:450–64. DOI: https://doi.org/10.1080/07420528.2017.1411360

13. Grgic J, Lazinica B, Garofolini A, et al. The effects of time of day-specific resistance training on adaptations in skeletal muscle hypertrophy and muscle strength: A systematic review and meta-analysis. Chronobiol Int 2019;36:449–60. DOI: https://doi.org/10.1080/07420528.2019.1567524

14. Chodzko-Zajko WJ, Proctor DN, Fiatarone Singh MA, et al. Exercise and physical activity for older adults. Med Sci Sports Exerc 2009;41:1510–30. DOI: https://doi.org/10.1249/MSS.0b013e3181a0c95c

15. Bae S, Lee S, Park H, et al. Position statement: exercise guidelines for osteoporosis management and fall prevention in osteoporosis patients. J Bone Metab 2023;30:149–65. DOI: https://doi.org/10.11005/jbm.2023.30.2.149

16. Bull FC, Al-Ansari SS, Biddle S, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. Br J Sports Med 2020;54:1451–62.

17. Izquierdo M, de Souto Barreto P, Arai H, et al. Global consensus on optimal exercise recommendations for enhancing healthy longevity in older adults (ICFSR). J Nutr Health Aging 2025;29:100401. DOI: https://doi.org/10.1016/j.jnha.2024.100414

18. Sedliak M, Finni T, Peltonen J, Häkkinen K. Effect of time-of-day-specific strength training on maximum strength and EMG activity of the leg extensors in men. J Sports Sci 2008;26:1005–14. DOI: https://doi.org/10.1080/02640410801930150

19. Souissi N, Gauthier A, Sesboüé B, et al. Effects of regular training at the same time of day on diurnal fluctuations in muscular performance. J Sports Sci 2002;20:929–37. DOI: https://doi.org/10.1080/026404102320761813

20. Krčmárová B, Krčmár M, Schwarzová M, et al. The effects of 12-week progressive strength training on strength, functional capacity, metabolic biomarkers, and serum hormone concentrations in healthy older women: morning versus evening training. Chronobiol Int 2018;35:1490–502. DOI: https://doi.org/10.1080/07420528.2018.1493490

21. Bull FC, Al-Ansari SS, Biddle S, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. Br J Sports Med 2020;54:1451–62. DOI: https://doi.org/10.1136/bjsports-2020-102955

22. World Medical Association Declaration of Helsinki. JAMA 2013;310:2191. DOI: https://doi.org/10.1001/jama.2013.281053

23. Bishop DJ, Beck B, Biddle SJH, et al. Physical Activity and Exercise Intensity Terminology: A Joint American College of Sports Medicine (ACSM) Expert Statement and Exercise and Sport Science Australia (ESSA) Consensus Statement. J Sci Med Sport 2025;28:981-91. DOI: https://doi.org/10.1016/j.jsams.2024.11.004

24. Sarabon N, Rosker J, Fruhmann H, et al. Reliability of maximal voluntary contraction related parameters measured by a novel portable isometric knee dynamometer. Physikalische Medizin, Rehabilitationsmedizin, Kurortmedizin 2013;23:22–7. DOI: https://doi.org/10.1055/s-0032-1331190

25. Rikli RE, Jones CJ. Development and validation of criterion-referenced clinically relevant fitness standards for maintaining physical independence in later years. Gerontologist 2013;53:255–67. DOI: https://doi.org/10.1093/geront/gns071

26. Makizako H, Shimada H, Doi T, et al. Predictive cutoff values of the five-times sit-to-stand test and the timed “up & go” test for disability incidence in older people dwelling in the community. Phys Ther 2017;97:417–24.

27. Dos Santos VR, Antunes M, dos Santos L, et al. Effects of different resistance training frequencies on body composition, muscular strength, muscle quality, and metabolic biomarkers in sarcopenic older women. J Strength Cond Res 2024;38:e521–8. DOI: https://doi.org/10.1519/JSC.0000000000004827

28. Pinto RS, Correa CS, Radaelli R, et al. Short-term strength training improves muscle quality and functional capacity of elderly women. Age (Omaha) 2014;36:365–72. DOI: https://doi.org/10.1007/s11357-013-9567-2

29. Zhao R, Zhao M, Xu Z. The effects of differing resistance training modes on the preservation of bone mineral density in postmenopausal women: a meta-analysis. Osteoporosis Int 2015;26:1605–18. DOI: https://doi.org/10.1007/s00198-015-3034-0

30. Schot PK, Knutzen KM, Poole SM, Mrotek LA. Sit-to-stand performance of older adults following strength training. Res Q Exerc Sport 2003;74:1–8. DOI: https://doi.org/10.1080/02701367.2003.10609058

31. Bruun IH, Mogensen CB, Nørgaard B, et al. Validity and responsiveness to change of the 30-second chair-stand test in older adults admitted to an emergency department. J Geriatric Physical Ther 2019;42:265–74. DOI: https://doi.org/10.1519/JPT.0000000000000166

32. Zhang F, Ferrucci L, Culham E, et al. Performance on five times sit-to-stand task as a predictor of subsequent falls and disability in older persons. J Aging Health 2013;25:478–92. DOI: https://doi.org/10.1177/0898264313475813

33. Green P, Woglom AE, Genereux P, et al. Gait speed and dependence in activities of daily living in older adults with severe aortic stenosis. Clin Cardiol 2012;35:307–14. DOI: https://doi.org/10.1002/clc.21974

34. Perez‐Sousa MA, Venegas‐Sanabria LC, Chavarro‐Carvajal DA, et al. Gait speed as a mediator of the effect of sarcopenia on dependency in activities of daily living. J Cachexia Sarcopenia Muscle 2019;10:1009–15. DOI: https://doi.org/10.1002/jcsm.12444

35. Amarante do Nascimento M, Borges Januário RS, Gerage AM, et al. Familiarization and reliability of one repetition maximum strength testing in older women. J Strength Cond Res 2013;27:1636–42. DOI: https://doi.org/10.1519/JSC.0b013e3182717318

36. Ploutz-Snyder LL, Giamis EL. Orientation and familiarization to 1RM strength testing in old and young women. J Strength Cond Res 2001;15:519–23. DOI: https://doi.org/10.1519/00124278-200111000-00020

37. Mora-Rodríguez R, Pallarés JG, López-Samanes Á, et al. Caffeine ingestion reverses the circadian rhythm effects on neuromuscular performance in highly resistance-trained men. PLoS One 2012;7:e33807. DOI: https://doi.org/10.1371/journal.pone.0033807

38. Tallis J, Duncan MJ, Wright SL, et al. Assessment of the ergogenic effect of caffeine supplementation on mood, anticipation timing, and muscular strength in older adults. Physiol Rep 2013;1:72. DOI: https://doi.org/10.1002/phy2.72

39. Norager CB, Jensen MB, Madsen MR, Laurberg S. Caffeine improves endurance in 75-yr-old citizens: a randomized, double-blind, placebo-controlled, crossover study. J Appl Physiol 2005;99:2302–6. DOI: https://doi.org/10.1152/japplphysiol.00309.2005