Decrease of plasma TNF-α and CRP levels in response to postexhaust resistance training and vitamin D supplementation in overweight healthy women

The purpose of this study was to investigate the simultaneous effect of resistance training and vitamin D supplementation on plasma CRP and TNF-α levels in overweight healthy women. The participants were randomly divided into four groups including: (1) placebo, (2) resistance training (RT), (3) vitamin D, and (4) RT + vitamin D. Interventions were performed for 8 weeks (3 days per week), consisting of resistance training protocol (60% 1-RM) and taking vitamin D (1000 IU per day). Fasting blood samples were collected 48 hours before and after the interventions. A significant decrease in CRP was reported among the studied groups (p=0.001, F=11.4). These changes showed a difference between RT + vitamin D compared to other groups. The CRP values ​​of the RT and vitamin D groups were also significantly lower than the placebo group (P = 0.03). TNF-α was significantly decreased among the studied groups (p = 0.003, F = 5.4). These changes showed a difference between the RT + vitamin D group compared to other groups. TNF-α was significantly lower in the RT and vitamin D groups than in the placebo group (P = 0.03). The findings of this study confirm that adaptation to resistance training, if combined with vitamin D intake, has significant effects on decreasing inflammatory biomarkers at rest. In addition, TNF-α alteration appears to be less effective than resistance training, which may be due to eccentric contractions caused by resistance training.