Type 2 Diabetes, Uncontrolled Blood Pressure, and a Request for Immediate HIIT
Robert, 58, is 178 cm and 98 kg (BMI 30.9). He has had type 2 diabetes for 6 years and takes metformin 1,000 mg twice daily plus insulin glargine 28 units at bedtime. He also takes lisinopril 20 mg for hypertension. Today his resting blood pressure is 148/92 mmHg and his resting heart rate is 78 bpm. His most recent A1c is 8.4%, and his fasting glucose log ranges from 90 to 190 mg/dL. He has not exercised in 3 years. He reports occasional numbness and tingling in both feet that has never been evaluated, and he wears over-the-counter shoe inserts. He wants to start high-intensity interval training because a coworker lost 12 kg doing it, and he asks you to "write the plan and start today." He has a physician appointment in 6 weeks.
1. Can you start him on HIIT today as requested? What clearances or referrals do you require, and why?
Read the worked answer
No. Writing and starting a HIIT plan today is not defensible with this presentation.
Blood pressure. 148/92 mmHg is stage 2 hypertension. Uncontrolled blood pressure at or above 140/90 is a relative contraindication to vigorous-intensity exercise, and HIIT by definition reaches that intensity. His pressure needs medical management and documented control before vigorous work.
Glycemic risk. An A1c of 8.4% with 28 units of bedtime basal insulin and fasting glucose swings from 90 to 190 mg/dL means meaningful hypoglycemia risk, especially with evening exercise.
Feet. Numbness and tingling bilaterally, never evaluated, raise concern for peripheral neuropathy. He needs a foot exam and footwear guidance before weight-bearing impact is progressed.
Action. Require medical clearance for exercise with specific attention to blood pressure and glucose control, request a foot evaluation, and refer to a diabetes educator or dietitian. Use a readiness screen such as PAR-Q+ and document everything. If his physician clears moderate-intensity activity, you may begin supervised low-impact work with glucose monitoring while awaiting the foot assessment - but not HIIT, and not today.
2. Assume he is cleared for moderate-intensity exercise only. Write weeks 1–4 and define the criteria for progressing toward intervals.
Read the worked answer
Weeks 1–4. Three to four sessions weekly on a stationary bike or in the pool to limit foot loading. Start at 10–15 minutes at RPE 3–4/10 (roughly 40–55% heart-rate reserve), building to 25–30 minutes by week 4. Include a 5-minute warm-up and cool-down, and stop for chest pain, dizziness, or unusual dyspnea. Add resistance training twice weekly, 1–2 sets of 10–12 reps on machines at RPE 4–6, with exhale on exertion and no breath-holding, because straining raises blood pressure acutely.
Monitoring each session. Blood pressure before and after; glucose before, and after if the session exceeds 30 minutes; daily foot checks for blisters or redness; a simple symptom log.
Progression criteria. Documented resting blood pressure below 140/90 from his physician, no hypoglycemia below 70 mg/dL, foot evaluation completed with footwear approved, and two consecutive weeks of 30-minute moderate sessions without symptoms. Only then introduce intervals as 4 × 1 minute at RPE 6–7 with 2 minutes of easy recovery - controlled intervals, not all-out sprints - and reassess every 2 weeks.
3. Build the hypoglycemia and safety plan, including timing, monitoring, and what you will not do yourself.
Read the worked answer
Timing matters. Bedtime glargine plus late-afternoon or evening exercise raises the risk of nocturnal hypoglycemia. Prefer morning or midday sessions, or move the session earlier and ensure a meal and glucose check follow it.
Monitoring. Check glucose before exercise; if below 100 mg/dL, take 15–20 g of rapid carbohydrate and recheck in 15 minutes. If above 250 mg/dL with symptoms or ketones, he should not exercise and should contact his physician. Check again after sessions longer than 30 minutes and before bed on training days. Keep 15–20 g fast-acting carbohydrate with him at all times and teach him the symptoms: shakiness, sweating, confusion, hunger, palpitations.
What you will not do. You will not adjust insulin doses, change his medication schedule, or tell him to skip a dose - that belongs to the prescriber. You will not clear him for vigorous exercise yourself. You will not proceed if he arrives with blood pressure at or above 140/90, symptomatic hypoglycemia, or an unexamined foot wound.
Communication. Send the prescriber his glucose and blood pressure logs, session tolerance, and any symptoms, and ask for written guidance on exercise timing relative to insulin. Log every session and every decision.