The study aimed to examine hamstring-quadriceps muscle activations of the supine bridge and reverse plank exercises that are performed for both improving the overall body strength and contributing to the treatment in the process following an injury on different grounds. Methods: Ten participants (four males and six females, age=26.70±3.02 years) without regular sports habits were included in the study. Bilateral supine bridge and bilateral reverse plank exercises were practiced randomly on stable and unstable grounds. In the study, muscle activation values of vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF) and semitendinosus (SEM) muscles of the participants were examined. Along with the muscle activation that occurred during the exercise, hamstring (BF+SEM)/quadriceps (VM+VL) ratio was also determined (H:Q). Results: The lowest co-activation ratio (most balanced H:Q activation) was observed on stable ground bridge exercise (5.83±4.04), and the largest co-activation ratio (hamstring dominant activation) was observed on stable ground plank exercise (8.84±6.60). No significant difference was found between exercises at H:Q co-activation ratio (p>0.05). A statistically significant difference was found in the quadriceps and hamstring group in terms of exercise and difference ground in favor of plank (p<0.05). Conclusion: Reverse plank exercise has greater agonist muscle activation than the supine bridge. Therefore, it is thought that bridge exercise could be advised in the rehabilitation process that necessitates a high level of balance, especially in co-activation ratio. Further study with various clinical problems may direct the process.