Abstract
Exercise-trained individuals exhibit greater immune system function, which may be attributed in part to enhanced peripheral blood mononuclear cell (PBMC) function. Exercise training is a potent stimulator of mitochondrial adaptation, which may help explain improvements in immunity. However, the mechanisms by which exercise acutely modulates PBMCs to promote beneficial adaptations remain unclear. Purpose: The purpose of this study was to test the hypothesis that a single bout of aerobic exercise modulates PBMC mitochondrial function. Methods: Twenty-eight healthy young adults (13 females, 15 males; age 21.84 ± 2.78 years) completed a graded exercise test (VO₂max: 41.4 ± 7.64 ml O₂·kg⁻¹·min⁻¹) followed by 30 minutes of cycling at 50% of maximal aerobic workload (132.78 ± 38.9 W). Blood was collected pre- and post-exercise. PBMCs were isolated, counted, and assessed for mitochondrial respiratory capacity using high-resolution respirometry. Paired t-tests compared respiratory states pre- and post-exercise, and unpaired t-tests assessed sex differences. Results: Acute exercise increased Complex I-supported State 3 respiration in females (pre: 8.81 ± 2.27, post: 10.73 ± 3.40 pmol O₂·s⁻¹·10⁻⁶ cells; p = 0.035), but not males (pre: 10.64 ± 3.61, post: 9.28 ± 2.60; p = 0.122). Females exhibited a greater relative change than males (25.36 ± 38.95% vs. –7.81 ± 25.86%; p = 0.017). Complex I+II-supported uncoupled respiration also increased in females (p = 0.033), but not in males (p = 0.221). No significant correlations were found between exercise intensity and respiratory changes. Discussion: These findings demonstrate that acute aerobic exercise enhances PBMC mitochondrial respiratory capacity in females, but not males, suggesting a sex-specific bioenergetic response. The effect was most prominent at Complex I, indicating differential reliance on NADH-linked pathways. This pilot study highlights PBMC mitochondrial function as a potential non-invasive marker of acute exercise responsiveness. However, modest sample size, lack of fitness-level controls, and assessment of only acute responses limit generalization. Future work should include larger, more diverse cohorts, evaluate PBMC subtype composition, and investigate whether these acute responses predict long-term adaptations.
Recommended Citation
Moon, Ryan R.
(2025)
"Sex-Specific Changes in PBMC Mitochondrial Respiration Following Acute Exercise,"
International Journal of Exercise Science: Conference Proceedings: Vol. 14:
Iss.
5, Article 101.
Available at:
https://digitalcommons.wku.edu/ijesab/vol14/iss5/101
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