Effects of Vertical Jump Performance and Ground Reaction Force Variables according to the Fatigue by Submaximal Treadmill Exercise. KINESIOLOGY, 2016, 18(3): 1-11. [PURPOSE] The purpose of this study was to investigate the effects. of the vertical jump and ground reaction force variables according to fatigue by submaximal treadmill exercise. [METHODS] We selected n=9 young and healthy men(mean age: 25.33±3.80 yrs, mean heights: 1.73±0.02 m, mean body weights: 69.65±6.79 kg). Fatigue was induced by a short period of strenuous exercise performed on a treadmill with using the Bruce protocol. The variables analyzed were the vertical jump height, ground reaction force(medial lateral[ML] GRF, anterior posterior[AP] GRF), peak vertical force[PVF], and dynamic postural stability index([MLSI, APSI, VSI, DPSI]) according to induced fatigue. [RESULTS] 1. Vertical jump heights was significantly lower posttest(p<.01). 2. AP GRF, PVF, and loading rate were significantly loewr posttest(p<.05). 3. Dynamic postural stability index(MLSI[left], VSI, DPSI) was significantly higher posttest(p<.05). 4. GRF variables showed similar correlation(PVF with loading rate r=.596[R2=35%], MLSI with APSI r=.816[R2=66%], VSI with DPSI r=.970[R2=94%]) according to induced fatigue(p<.05). [CONCLUSIONS] In conclusion, fatigue alters vertical jump performance and landing performance including changes in dynamic stability; and GRF magnitudes. Also future research should continue to investigate the different GRF responses that occur during landing after fatigue.