Caffeine Does Not Augment Markers of Muscle Damage or Leukocytosis Following Resistance Exercise

Purpose: The purpose of this study was to evaluate the effects of caffeine ingestion before a resistance exercise session on markers of muscle damage (CK, LDH. ALT, AST) and leukocyte levels. Methods: Fifteen soccer athletes completed two resistance exercise sessions that differed only in the ingestion of caffeine or a placebo preworkout. Results: CK concentration increased significantly following the caffeine session (415.8 +/- 62.8 to 542.0 +/- 73.5) and the placebo session (411.5 +/- 43.3 to 545.8 +/- 59.9), with no significant differences between sessions. Similarly. LDH concentration increased significantly following the caffeine session (377.5 +/- 18.0 to 580.5 +/- 36.1) and the placebo session (384.8 +/- 13.9 to 570.4 +/- 36.1), with no significant differences between sessions. Both sessions resulted in significant increases in the total leukocyte count (caffeine = 6.24 +/- 2.08 to 8.84 +/- 3.41; placebo = 6.36 +/- 2.34 to 8.77 +/- 3.20). neutrophils (caffeine = 3.37 +/- 0.13 to 5.15 +/- 0.28; placebo = 3.46 +/- 0.17 to 5.12 +/- 0.24), lymphocytes (caffeine = 2.19 +/- 0.091 to 2.78 +/- 0.10; placebo = 2.17 +/- 0.100 to 2.75 +/- 0.11), and monocytes (caffeine = 0.53 +/- 0.02 to 0.72 +/- 0.06; placebo = 0.56 +/- 0.03 to 0.69 +/- 0.04), with no significant differences between sessions. Conclusion: Ingestion of caffeine at 4.5 mg.kg(-1) did not augment markers of muscle damage or leukocyte levels above that which occurs through resistance exercise alone.