Countermovement jump test valid in runner fatigue detection
This novel study analyzed the changes in training-load values and countermovement jump (CMJ) results as indicators of stress and fatigue in a high-level 800-m runner during a whole season, including indoor (ID) and outdoor season (OD).
Over 42 weeks, daily training load was quantified as the result of intensity and volume, and was termed, Load Index (LI).
CMJ was measured in every running session after warm-up and immediately after the last effort of the session. Other jump-related variables such as CMJ height loss, average weekly CMJ, initial CMJ of the next consecutive session, and initial CMJ of the following week were also studied.
The results observed a significant negative relationship between LI and weekly CMJ (ID: r = -.68, P < .001, common variance [CV] = 46%; OD: r = -.73, P < .001, CV = 53%); initial CMJ of the following week (OD: r = -.71, P < .01, CV = 50%); and CMJ height loss (ID: r = -.58, P < .01, CV = 34%; OD: r = -.52, P < .01, CV = 27%).
A significant positive relationship was observed between LI and initial CMJ of the next consecutive session when LI values were <8 (OD: r = .72; P < .01, CV = 52%). However, from values ≥8, the relationship became significantly negative (ID: r = -.74; P < .01, CV = 55%; OD: r = -64, P < .01, CV = 41%).
In conclusion, researchers stated that CMJ may be a valid indicator of the degree of stress or fatigue generated by specific training sessions of a competitive athlete within a single session, a week, or even the following week. There could be an individual limit LI value from which the training volume does not allow a positive effect on high-speed actions such as CMJ in the next consecutive session.
Load Index and Vertical Jump to Monitor Neuromuscular Fatigue in an Elite 800-m Athlete.
Int J Sports Physiol Perform. 2021 Feb 24;1-5. doi: 10.1123/ijspp.2020-0474.