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
Free tracker included with every download this week
Weight Loss and Working Out — A Practical Guide
Exercise is a key part of sustainable weight loss, but working out alone won't create the dramatic results many people expect. The reality is that weight loss primarily comes from a calorie deficit — typically achieved through dietary changes — while regular physical activity supports weight management, improves cardiovascular health, and helps preserve muscle during weight loss. Understanding how exercise fits into a weight loss strategy, and how to combine it safely with other approaches like medication or dietary changes, is essential for long-term success. This guide covers the evidence-based approach to weight loss and working out in the UK context.
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Calculate Your BMI Instantly
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.
How Exercise Supports Weight Loss
Exercise contributes to weight loss in several ways, but it's important to understand the realistic contribution. A typical 30-minute moderate-intensity workout burns approximately 200–300 calories, depending on your body weight and fitness level. To lose 0.5 kg per week — the NHS recommended safe rate — you need a calorie deficit of about 3,500 calories over the week, or 500 calories per day. This means exercise alone rarely creates sufficient deficit; instead, it works best alongside dietary changes.
Regular physical activity offers additional benefits beyond calorie burn: it preserves muscle mass during weight loss, improves insulin sensitivity and blood sugar control, strengthens bones and joints, and supports cardiovascular health. For weight management in the UK, the NHS recommends at least 150 minutes of moderate-intensity aerobic activity per week, plus strength training twice weekly. If you're using prescription weight loss medication like Mounjaro or Wegovy, exercise amplifies the benefits by supporting muscle retention and metabolic health.
Clinically BackedWeight Loss
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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
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
Combining Diet, Exercise, and Medical Support
The most effective weight loss approach combines dietary changes, regular physical activity, and — when clinically appropriate — prescription medication. If you're eligible for weight loss medication through NHS specialist services or private prescribing, these medications work best alongside a reduced-calorie diet and increased physical activity, not instead of them. Use our free BMI calculator to check your starting point, and our GLP-1 weight loss calculator to explore how medication might support your goals. Track your progress with our free progress tracker to stay motivated and monitor improvements in fitness, energy levels, and weight over time. Always consult your GP before starting a new exercise programme, especially if you have existing health conditions or are taking medications.
- 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 many calories does exercise burn for weight loss?
Calorie burn depends on activity type, intensity, and body weight. Moderate-intensity exercise typically burns 200–400 calories per 30 minutes. However, diet creates the primary calorie deficit — NHS guidance recommends a 500 kcal daily deficit for safe 0.5 kg weekly loss. Exercise supports this by increasing total daily burn and preserving muscle.
Can you lose weight with exercise alone, without changing diet?
It's very difficult. Exercise alone rarely creates sufficient calorie deficit for meaningful weight loss. Combining exercise with dietary changes (eating fewer calories from processed foods, sugar, and excess fat) produces much better results. Most successful weight loss combines both approaches.
What's the best type of exercise for weight loss?
A combination works best: aerobic exercise (walking, running, cycling) burns calories during activity, while strength training (weights, resistance) builds muscle that increases resting metabolic rate. The NHS recommends 150 minutes moderate aerobic activity weekly plus strength training twice weekly for optimal health.
Does exercise help if I'm taking Mounjaro or Wegovy?
Yes. These GLP-1 medications work best alongside diet and exercise. Physical activity supports muscle retention, improves cardiovascular health, and enhances metabolic benefits. Clinical trials of these medications combined lifestyle changes with medication — neither alone is as effective as the combination.
How quickly will I see weight loss results from working out?
Weight changes take time. Safe, sustainable loss is 0.5–1 kg per week. Initial changes in fitness, energy, and how clothes fit often appear before significant scale movement. Use our free progress tracker to monitor improvements beyond weight, including strength gains and consistency in your routine.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.