Difficulty recruiting subjects; funding not renewed.

This will be a randomized pilot study to determine the effectiveness of Personalized Blood Flow Restriction (PBFR) technique in conjunction with prescribed physical therapy (PT) in a cohort of anterior cruciate ligament (ACL) reconstruction subjects

This will be a randomized pilot study to determine the effectiveness of Personalized Blood Flow Restriction (PBFR) technique in conjunction with prescribed physical therapy (PT) in a cohort of anterior cruciate ligament (ACL) reconstruction subjects. Both groups of subjects will undergo unilateral ACL reconstruction at University of Arkansas for Medical Sciences (UAMS), followed by prescribed PT at the UAMS Orthopedic Clinic at Colonel Glenn.

Up to 25 subjects will be enrolled. Half are randomized to the BFR group with the other will perform PT without BFR.

Data collection will occur at four approximate occasions: pre-surgery, 8-weeks postop, 12-weeks postop, and 16-weeks postop.

Inclusion Criteria:

1. Men and women, ages 18-34 years.
2. Scheduled to undergo elective ACL surgery at UAMS.
3. Capable of providing informed consent.
4. Willing to exercise with BFR.
5. COVID-19 negative or asymptomatic.

Exclusion Criteria:

1. Any surgical indication other than ACL repair.
2. Body mass index >40.
3. Pregnant female.
4. Neurological, musculoskeletal, or other disorder that would preclude them from completing the exercise training intervention and all performance tests.
5. Hypertension as evidenced by systolic BP >150 at rest OR diastolic BP >85 at rest.
6. Heart failure as evidenced by use of prescription diuretics.
7. History of atrial fibrillation.
8. Oxygen saturation <95% on room air at rest.
9. Any other medical condition that would interfere with testing or increase one's risk of complications during exercise.
10. Currently receiving androgen (e.g., testosterone) or anabolic (e.g., GH, IGF-I) therapy.
11. Compromised vascular circulation in the legs (e.g. peripheral vascular disease).
12. History of deep vein thrombosis.
13. Varicose veins in the legs.
14. Known Sickle cell disease or trait.
15. Unwilling to avoid using protein or amino-acid supplements during participation.
16. Unwilling to avoid using BFR during prescribed post-operative physical therapy.

20 weeks