The purposes of this dissertation were to investigate the acute effects of branched-chain amino acids on psychological, physiological, and subsequent performance changes following high volume resistance training. The rationale for this study design was based on abrupt or contiguous training/ competitions that specific athletes encounter in a competitive season. This study design also sought to fill some gaps in the scientific literature concerning the efficacy of BCAAs for subjective fatigue in a resistance training paradigm. To address the purposes of this dissertation, a one-week study was conducted on resistance trained males, in which half of the subjects were randomly selected to receive BCAAs and the other half was a non-supplement group. The subjects in this study performed two high volume resistance training bouts consisting of squat and bench press (5 sets x 10 repetitions at 95% relative intensity) separated by two days. The physiological variables tested in this study were creatine kinase, interleukin-6, C-reactive protein, testosterone, and cortisol. The performance variables tested in this study were static and counter-movement jumps, isometric mid-thigh pull, and Bosco repeated jumps. The primary findings from this study was that subjects in the BCAA group had a statistically significant decrease in muscle damage, indicated by levels of CK. Additionally, there was a statistically significant increase in T:C ratio for the BCAA group compared to the NS group. Concerning performance variables, BCAAs had a small to moderate effect on rate of force development; however, this result was not statistically significant. There were no differences in psychological variables between the groups. Based on the findings of this dissertation, BCAAs mitigate levels of muscle damage and rate of force development. To conclude, BCAAs may provide a competitive advantage for athletes when training volume and competitions become contiguous.

The primary purposes of this dissertation were to explore relationship between cell free DNA (cf-DNA), creatine kinase (CK), C-reactive protein (CRP), vertical jump testing delayed onset muscle soreness (DOMS) in response to a high-volume resistance training protocol, and to assess the sensitivity of cf-DNA to different resistance training volume loads. The secondary purpose was to examine the relationship between cf-DNA and relative strength. Study 1 was an exploratory attempt to discover relationships between cf-DNA, CK, CRP, delayed onset muscle soreness, and performance variables. Seventeen resistance trained males were recruited, 9 were randomly assigned to receive BCAAs while 8 received a placebo. Participants performed a high-volume resistance training session consisting of the back squat and bench press. Blood was drawn to measure serum cf-DNA, CK, and CRP levels prior to the training session, with cf-DNA collected immediately post, and CK and CRP at 24hr and 48hrs post. Self-reported DOMS on a scale of 1 to 10 was collected prior to training on day 2, day 3, and day 4. SJH, CMJH, and BOSCO were collected on day 1, day 3, and day 4. Fifty-seven correlations were run to explore the relationships between variables. Only the correlation between %Δ DOMS 48hr and %Δ CRP 48hr in the non-supplement group was significant (p = 0.02). The second study, designed to assess the sensitivity of cf-DNA to different resistance training volume loads, consisted of a high-volume resistance training protocol. Blood was drawn immediately before the resistance training session (T1), immediately after the third lifting set (T2), and immediately after the sixth lifting set (T3). cf-DNA increased significantly from T1 to T2 (p < 0.01) and T1 to T3 (p < 0.01). The linear regression model used to examine the capabilities of relative strength to predict %Δ cf-DNA from T1 to T3 was significant (p = 0.04). The results of this study demonstrate the short response time of cf-DNA in relation to variations in resistance training volume-load, suggesting it may be a valuable marker in monitoring the immune response to volume-load. Results also demonstrated the positive relationship between relative strength and %Δ cf-DNA.