The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
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Target Heart Rate Zone For Weight Loss — What You Need to Know
Your target heart rate zone is the range where your heart beats during exercise to maximise fat burning and cardiovascular benefit. For weight loss in the UK, most adults benefit from exercising at 50–85% of their maximum heart rate — typically 100–170 beats per minute. However, weight loss involves more than just exercise. Many people combine cardio training with dietary changes and, if eligible, prescription weight loss medication such as Mounjaro or Wegovy. This guide covers heart rate zones and how they fit into a complete UK weight management approach.
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Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
Understanding Your Target Heart Rate Zone for Exercise
Your maximum heart rate is roughly 220 minus your age. For a 40-year-old, this is approximately 180 beats per minute (bpm). Your target zone for fat-burning exercise is 50–85% of this maximum — in this example, 90–153 bpm.
- 50–70% intensity (light cardio): Good for beginners, sustainable for longer duration, builds aerobic fitness
- 70–85% intensity (moderate to vigorous): More effective for calorie burn and weight loss, requires better fitness level
- Above 85% (very high intensity): Short bursts, high calorie burn, recovery needed between sessions
You can monitor heart rate using a smartwatch, fitness tracker, or by counting your pulse manually. The talk test is simple: during moderate intensity, you should be able to speak but not sing. During vigorous intensity, speaking is difficult.
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How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
Free Weight Loss Tools & Guides
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Weight Loss Medication Options Available in the UK
Exercise alone is effective for some, but many people find that combining physical activity with prescription weight loss medication produces better results. In the UK, three medications are licensed for weight management: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). These are GLP-1 receptor agonists that help reduce appetite and support feeling fuller after meals. Clinical trials show average weight loss of 15–21% of body weight when combined with exercise and a reduced-calorie diet. To find out if you're eligible, speak with your GP or use an online assessment with a UK-licensed prescriber. Eligibility depends on your BMI and any weight-related health conditions such as high blood pressure or type 2 diabetes.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
How do I calculate my target heart rate zone?
Subtract your age from 220 to find your maximum heart rate. Then multiply by 0.50 and 0.85 to find your target zone. For example, a 35-year-old has a max of 185 bpm; their zone is 92–157 bpm. Use this zone during cardio exercise like running, cycling, or swimming.
Is a higher heart rate zone always better for weight loss?
Not necessarily. Moderate intensity (50–70%) is sustainable for longer and burns significant calories. Very high intensity (above 85%) burns more calories per minute but is harder to maintain. Most people benefit from mixing moderate and vigorous sessions throughout the week.
Can I use prescription weight loss medication without exercise?
Prescription medications like Mounjaro and Wegovy are most effective when combined with reduced-calorie diet and increased physical activity. They support appetite control and help you stick to healthier habits, but they work best alongside lifestyle changes, not instead of them.
What's the difference between Mounjaro and Wegovy for weight loss?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist; Wegovy (semaglutide) is a GLP-1 agonist only. In clinical trials, Mounjaro produced slightly higher average weight loss (15–21% vs 15%), but individual results vary. Both are once-weekly injections available through NHS specialist services or private prescription in the UK.
How do I find out if I'm eligible for weight loss medication on the NHS?
Eligibility depends on your BMI and health conditions. Generally, adults with a BMI of 30 or above, or 27–29.9 with weight-related conditions, may qualify. Speak with your GP about referral to a tier 3 specialist weight management service. Regional availability varies; waiting lists can be long in many areas. Private online prescribing is also available if you prefer faster access.
Ready to take control of your weight loss journey?
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