Health and Medical Psychology Health and Medical Humanities

Time-of-Day Effects of Acute Strength Training on Hormonal and Hematological Responses in Female Weightlifters

https://doi.org/10.61838/ijbmc.v13i3.1273
Strength training chronobiology hormonal response hematological response female athletes

Authors

  • Suhailah S. Al-Jameel Department of Chemistry, College of Science, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia.
  • Mona Mostafa Abdo Sakoury Department of General Courses, Faculty of Applied Studies and Community Service, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.
  • Haitham Fayez Mahmoud Akl Department of General Courses, Faculty of Applied Studies and Community Service, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.
  • Mohamed Mahmoud Ahmed Arands Assistant Professor in the Department of Theory and application of compact and individual Sports, Faculty of Sport Sciences, Arish University, Al-Arish, Egypt.
  • Nehal Hassan Nashat Zaki Qutb Assistant Professor, Department of Biosciences and Sports Health, Faculty of Physical Education for Girls, Al Jazeera, Helwan University, Cairo, Egypt.
  • Mohammed Nader Shalaby
    dr.m.nader@suez.edu.eg
    Professor of Sports Biology, Biological Sciences and Sports Health Department, Faculty of Physical Education, Suez Canal University https://orcid.org/0000-0002-0228-3003
  • Ayoub M. H Abuzaher Professor, University College of Applied Sciences, Department of Physical Education, Gaza, Palestine.
  • Sherin Hussien Department of Health Sciences, Faculty of Education, Western University, London, Canada; Department of Health Sciences, Faculty of Physical Education for Girls, Alexandria University, Alexandria, Egypt.
Vol. 13 No. 3 (2026): March
Quantitative Study(ies)

Objective: This study investigated the acute effects of strength training performed at different times of day on hormonal, hematological, and biochemical responses in trained female weightlifters.

Methods and Materials: Thirty female athletes with at least three years of resistance training experience completed standardized high-intensity strength training sessions in the morning (7:00–9:00 AM) or afternoon (5:00–7:00 PM) at intensities ranging from 75–90% of one-repetition maximum (1RM). Venous blood samples were collected at rest and immediately post-exercise to assess hematological parameters (white blood cell count and subtypes, red blood cells), hormonal markers (testosterone and cortisol), and creatinine levels.

Findings: Both morning and afternoon training sessions resulted in significant post-exercise increases in total white blood cell counts, indicating an acute immune response to strength training. Neutrophil counts increased following morning training, whereas changes in lymphocyte, monocyte, and red blood cell counts were not statistically significant at either time of day. Testosterone and cortisol levels did not change significantly following morning or afternoon sessions. Creatinine levels increased significantly following afternoon training, suggesting a greater acute metabolic response at this time of day. Comparisons between morning and afternoon sessions revealed no significant time-of-day differences for most hormonal and hematological parameters.

Conclusion: These findings indicate that acute high-intensity strength training elicits largely comparable hormonal and hematological responses across training times. At the same time, biochemical stress—reflected by creatinine—may be more pronounced following afternoon sessions.

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