The Relationship Between Cell-Free DNA and Resistance Training Volume Load

The primary purpose of this study was to assess the sensitivity of cell-free DNA (cf-DNA) to different resistance training volume loads. The secondary purpose was to examine the relationship between change in cf-DNA and relative strength. Researchers hypothesized that (a) cf-DNA concentrations would increase with increasing volume load and (b) increases in relative strength would result in predicted decreases to %Delta of cf-DNA. Thirty subjects were recruited for this study, 15 men and 15 women. Blood was collected through venous draws into 4-ml vacutainers at 3 time points: immediately before (T1), after 3 sets (T2), and after 6 sets (T3) of the back squat exercise. A critical alpha of 0.05 was set for inferential statistics. A repeated-measures ANOVA showed that cf-DNA increased significantly from T1 (407.72 +/- 320.83) to T2 (1,244.6 +/- 875.83) (p < 0.01) and T1 (407.72 +/- 320.83) to T3 (1,331.15 +/- 1,141.66) (p < 0.01), whereas no difference was found from T2 to T3 (p = 1.00). The linear regression model used to examine the predictive capabilities relative strength had on cf-DNA %Delta from T1 to T3 was found to be significant (p = 0.04; R-2 = 0.15). The results of this study demonstrate the short response of cf-DNA in relation to variations in resistance training volume load. Results also demonstrated the positive relationship between relative strength and cf-DNA %Delta. The current study builds on the body of research that cf-DNA provides insight regarding the level of immune response after exercise training.