The goal of this randomized clinical trial study is to compare low-load blood flow restriction (LL-BFRt), sham LL-BFRt, and high-load eccentric training (HL-Et) in healthy level 1 sportsman. The main questions it aims to answer are:

1. Does LL-BFR improve muscle strength better than sham LL-BFRt and HL-Et?
2. Does LL-BFR improve dynamic stability better than sham LL-BFRt and HL-Et?
3. Does LL-BFR prevent ACL injury better than sham LL-BFRt and HL-Et?

Participants will be randomized into three intervention groups: LL-BFRt, sham LL-BFRt, and HL-Et. Participants will be asked to do:

• In LL-BFRt, participants will be asked to do LL eccentric training (including double leg squats, split squats, deadlifts, and monster walks) with a 30% of repetition maximum (RM) and 70% of arterial occlusion pressure (AOP).
• In sham LL-BFRt, participants will be asked to do LL eccentric training with a 30% of repetition maximum (RM) and 10% of arterial occlusion pressure (AOP).
• In HL-Et, participants will be asked to do LL eccentric training with a 70% of repetition maximum (RM).

Researchers will compare LL-BFRt, sham LL-BFRt, and HL-Et to see if muscle strength, dynamic stability, and ACL injury prevention improve after the interventions and follow-up.

Participants will be asked to do five sets of ten repetitions of each eccentric training, one-minute rest interval for each eccentric training and two mins rest interval between each set.

Inclusion Criteria:

• Being 15-35 years old
• Perform sports level 1 (soccer, basket ball, futsal, combat martial art) at least twice per week.
• Never had an history of ACL injury
• Never had an history of sprain or strain grade III
• Agree to participate until the end of this study period and sign the inform consent

Exclusion Criteria:

• Having hypertension, blood circulation disease, anemia, obesity, diabetes, kidney failure, vena thromboembolic, cancer, and tumor.
• Disabilities or disabled people.