Background: Regular exercise is beneficial to patients with hypertension and/or diabetes mellitus. However, most patients cannot maintain exercise habit. The investigators had developed a program called the "exercise is medicine"(EIM), combining motivational technique, information technology use and teaching exercise techniques. Before using this intervention in a main randomized controlled trial, the investigators would like to test its feasibility and acceptability. It is hypothesized that this program is feasible and acceptable to patients.

Method: 40 patients with HT and/or DM will be recruited to attend the EIM intervention. Primary outcomes will be the rate of recruitment and rate of retention. Other clinical outcomes will be obtained before and immediately after the 12-week program.

Inclusion Criteria:

• clinic systolic BP(SBP) higher than 130mmHg (for HT class) because the Hong Kong primary care office guideline, as of Jan 2019, regarded good control of SBP to be ≤130mmHg, OR HbA1c >7% (for DM class)
• self-reported regular exercise of ≤3 times per week - this cut-off is arbitrary but people who exercise more than 3 times may have little space for improvement; and these patients will unlikely be referred to EIM when it is implemented in routine clinical practice, - who have used any mobile apps on their phone (because the intervention involve use of apps to monitor and remind regular exercise)

Exclusion Criteria:

• patients with diagnosed chronic obstructive lung disease and recent stroke (within last 12 months) are excluded because there are other evidence-proven and well-structured programmes for these patients in the Hospital Authority (HA), for instance, pulmonary rehabilitation program conducted by physiotherapy and/or occupational therapist in HA. - - acute myocardial infarction in last 6 months
• ongoing angina
• uncontrolled cardiac arrhythmia
• acute diseases including known active endocarditis/acute pulmonary embolism, pulmonary infarction, deep vein thrombosis, acute aortic dissection, acute myocarditis
• known aortic stenosis
• known heart failure
• known obstructive left main coronary artery stenosis
• uncontrolled ventricular rates
• complete heart block
• known hypertrophic obstructive cardiomyopathy
• mental impairment that limit co-operation
• resting blood pressure with systolic blood pressure >180mmHg or diastolic blood pressure >110mmHg
• known anaemia with haemoglobin level less than 11gm/dL
• known uncorrected electrolyte imbalance
• known uncontrolled hyperthyroidism.
• For DM patients, patients with proliferative diabetic retinopathy and recent retinal bleeding (in last 12 months) are also excluded due to reports that vigorous exercise may increase blood pressure and led to retinal bleeding in these patients

Will make available on personal requests to investigators