Participants randomised to this group will undertake a remotely supervised 12-week home-based isometric exercise training intervention 3 times per week. The bilateral leg isometric exercise consists of 5-stage wall squat position determined by individual calculations at baseline. Rate of perceived exertion (RPE) will be monitored throughout the intervention and used to guide the squat stage position. Lifestyle change advice will be given in accordance with NICE guidelines for hypertension. Participants will receive a smartwatch (Huawei D2) to monitor their daily physical activity (step count) and record their home blood pressure.

Participants randomised to this group will not receive any intervention other than lifestyle change advice in accordance with NICE guidelines for hypertension. Participants will receive a smartwatch (Huawei D2) to monitor their daily physical activity (step count) and record their home blood pressure.

The intervention consists of two distinct phases:

• Intensive Phase (12 weeks) - a structured, high-support period involving three weekly supervised isometric exercise sessions and lifestyle change advice. The supervised exercise programme will consist of 4 × 2-minute bouts of wall squat exercise, with 2-minute rest periods between bouts. Participant squat height position will be based on individual calculations determined at baseline. Target rate of perceived exertion (RPE) for each bout will be:

• Bout 1: RPE 4 (target range: 3.5-4.5)
• Bout 2: RPE 5.5 (target range: 5-6)
• Bout 3: RPE 7 (target range: 6.5-7.5)
• Bout 4: RPE 8.5 (target range: 8-9) If the RPE falls outside the target zone for a given bout, participants will adjust their squat height accordingly.

Lifestyle change advice will be given in booklet form in accordance with current NICE guidelines for hypertension.

• Maintenance Phase (12-24 weeks) - focus on sustaining exercise and lifestyle behaviour changes

Feasibility will be determined by the rate of screening, eligibility, recruitment, and retention at 12 and 24 weeks.

Feasibility will be determined by adherence to the intervention (number of sessions attended and completed)

Participant acceptability will be determined through a qualitative process evaluation involving semi-structured interviews. The interviews will identify action mechanisms, examine experiences, barriers, facilitators, and behaviour change strategies, with a diverse sample to reflect varied demographics. Participants will be asked about their experience of participating in the study, thoughts, and attitudes towards the intervention.

Blood pressure will be measured in mmHg via office and ambulatory methods. Office BP will be taken in a seated position in accordance with resting BP protocols. Ambulatory BP monitoring will be performed with a non-invasive oscillometric device placed on the nondominant arm and programmed to perform measurements every 15 minutes for 24 hours. The secondary outcome is the change in mmHg for systolic and diastolic blood pressure from baseline, 12 weeks, and 24 weeks.