Musculoskeletal and Inflammatory Response to a Single Session of High-Volume Plyometric Exercise over Four Hours

Introduction: Plyometric exercise is commonly used to improve strength, power, and performance. However, there are very few studies that have characterized the biomarker response to plyometric training using a time-course approach. Objective: The purpose of this study was to determine the blood biomarker response to an acute high-volume session of plyometric exercise in young healthy adults at seven timepoints over the course of four hours. We hypothesized that exercise would increase biomarkers for muscle damage, cartilage metabolism, and inflammation. Methods: Twelve participants (10 male, 2 females; age 25±6y), performed 10 sets of 10 plyometric jumps at 40% of their 1-repetition max on a Plyo-press. Blood samples were collected before (PRE), immediately post-exercise (POST), and +15min, +30min, +1h, +2h, and +4h after exercise. Serum was measured for creatine kinase (CK), lactate dehydrogenase (LDH), high sensitivity C-reactive Protein (hsCRP), interleukin-6 (IL-6), C-terminal telopeptide of type 1 collagen II (CTXII), cartilage oligomeric matrix protein (COMP), and myoglobin (MYO). Data were analyzed using a repeated measures ANOVA. If significant time effects were found (p < 0.05), a Dunnett’s post-hoc analysis was used to determine changes for each timepoint compared to PRE. Data are presented as mean±SD. Results: We found a time effect (p<.01) for CK (PRE: 62±9.1 U/L, POST: 173±63, +15min: 181±67.2, +30min: 187±78.6) where +1h (173±62.9, p<.05), +2h (191±65, p<.01), and +4h (207±84, p<.05) were higher than PRE. There was no difference in LDH (PRE: 68±0.3 U/L, POST: 159±39.4, +15min: 159±39.4, +30min: 164±46.5 +1hr: 163±36.3, +2h: 167±36.1, +4h: 172±32.8) or hsCRP (PRE: 0.3±0.8 mg/L, POST: 1.6±2.7, +1h: 1.8±2.9, +2h: 1.9±3.5, +4h: 2.1±4.3) over time (all p>.05). There was a time effect (p<.01) for COMP (PRE: 31±0.4 pg/ml) where POST (169±36.8, p<.01) and +15min (1509±31.9, p<.05) were higher than PRE but not different than +30min (132±31.9), +1h (131±30.4), +2hr (144±34.9), and +4h (144±34.9). CTXII (PRE: 211±327 pg/ml, POST: 1520±1570, +15min: 1714+1911, +30min:1650±2010, +1h: 962±995, +2h: 1175±784, +2h: 1013±1227, p<.05) and IL-6 (PRE:.04±.6, POST: 1.9±2.1, +15min: 2.9±2.6, +30min: 2.4±2.3, +1h: 2.9±3.7, +2h: 3.5±4, +4h:5.7±5.5) both had a main effect of time (p<.01), but no timepoints survived posthoc adjustments. Finally, MYO demonstrated a time effect (PRE: 3.5±4.6) with +15min (69.7±18.7), +30min (77.5±29.5), +1h (78.4±26.7), +2h (75.6±29.6), and +4h (77.1±30.7) increased compared to PRE (all, p<.05). Conclusion: Our results suggest a high-volume session of plyometric exercise can increase biomarkers of muscle damage and cartilage metabolism, but not inflammation. This exercise modality could be used as a model to test nutrition, pharmaceutical, or supplement interventions that influence these biomarkers. The views expressed in this abstract are those of the authors and do not reflect the official policy of the Department of Army, Department of Defense, or the U.S. Government. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.