Exercise-induced hypertension (EIH) is associated with elevated risks of arrhythmia, coronary artery disease, arterial stiffness, and sudden cardiac death. Blood flow restriction (BFR) training has been proposed as a non-pharmacological intervention. This study aimed to evaluate whether changes in cardiovascular biomarkers accompanied hemodynamic improvements following BFR training in middle-aged runners with EIH. This secondary analysis included 28 male runners with EIH (mean age: 57.4 ± 6.5 years) from a prior cohort applying the same BFR training protocol. Participants exhibited a maximal systolic blood pressure ≥210 mmHg during graded exercise testing (GXT) and were assigned to a BFR training group (BFRTg, n = 16) or a control group (non-BFRTg, n = 12). BFR training was performed twice weekly for 20 minutes over 8 weeks. Cardiorespiratory fitness and hemodynamic response during GXT were also assessed. Cardiovascular biomarkers (endothelin-1 [ET-1], high-sensitivity C-reactive protein [hs-CRP], NT-proBNP, and nitric oxide [NO]) were measured pre- and post-intervention. In the BFRTg, ET-1, hs-CRP, and NT-proBNP levels decreased after BFR training, while maximal systolic blood pressure decreased and VO₂max increased (all p < .05). Hemodynamic load also improved, as indicated by reductions in resting and maximal rate-pressure product (RPP) and pulse pressure during maximal exercise (all p < .05). BFR training improved the exercise blood pressure response and cardiorespiratory fitness in runners with EIH. The reduction in hemodynamic load, reflected by decreases in RPP and PP, was accompanied by significant reductions in ET-1, hs-CRP, and NT-proBNP.