Abstract

BACKGROUND: It has been indicated that the acute exercise increases the thrombotic events that stem from platelet hyper-reactivity. The present randomized controlled trial study was carried out with the aim to compare high-intensity interval exercise (HIIE) with moderate intensity continuous exercise (MICE) in terms of platelet indices and function in patients who had undergone post coronary artery bypass graft (CABG). METHODS: 30 men with a history of CABG were recruited and divided into 3 groups (MICE, HIIE-1, and HIIE-2). The MICE protocol consisted of running for 40 minutes with 65 of maximal heart rate (HRmax). Subjects in HIIE-1 group performed an interval exercise with work to rest ratio of 1:1 in which 10 rounds of running (95 HRmax) were followed by active recovery (35 HRmax). HIIE-2 subjects performed an interval exercise with work to rest ratio of 2:1 in which 7 rounds of running (85 HRmax) were followed by active recovery (45 HRmax). Before and immediately after the exercise protocols, blood samples were taken from subjects and analyzed to measure the variables. RESULTS: Although platelet count (PLT) and hematocrit (HCT) were increased significantly after HIIE-1 and HIIE-2 in comparison to MICE (P < 0.050), the other platelet indices mean platelet volume (MPV), platelet distribution width (PDW), plateletcrit (PCT) were not significantly changed among groups (P > 0.050). The platelet aggregation and fibrinogen were further increased after HIIE-1 and HIIE-2 as compared with MICE; however, such increment were significant between HIIE-2 and MICE (P < 0.050). CONCLUSION: It seems that HIIE, regardless of the type, has higher thrombotic potentials compared with MICE. Accordingly, MICE is safer than HIIE for rehabilitation in patients undergoing CABG.