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
Best HIIT Workout for Weight Loss
High-intensity interval training (HIIT) is one of the most effective exercise methods for weight management in the UK. HIIT involves short bursts of intense activity followed by recovery periods, and evidence suggests it can help burn calories and support weight loss when combined with healthy eating habits. For sustainable weight management, HIIT works best alongside dietary changes and, where appropriate, other weight loss interventions. This guide explains how HIIT supports weight loss, what makes an effective workout, and how to get started safely.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 HIIT Supports Weight Loss
HIIT increases calorie burn in multiple ways. During intense intervals, your body uses significant energy, and the afterburn effect (elevated metabolic rate for hours post-workout) continues burning calories at rest. Research shows HIIT can be more time-efficient than steady-state cardio — you achieve results in 20–30 minutes rather than longer sessions.
- Builds lean muscle mass, which increases resting metabolism
- Improves insulin sensitivity, supporting blood sugar control
- Boosts cardiovascular fitness and aerobic capacity
- Reduces visceral fat (deep abdominal fat linked to health risks)
For sustainable weight loss in the UK, the NHS recommends combining HIIT with a reduced-calorie diet — exercise alone without dietary change produces modest results. HIIT should be part of a comprehensive weight management approach alongside healthy eating and adequate recovery.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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.
Creating an Effective HIIT Workout Plan
A basic HIIT session works like this: warm up for 5 minutes, then alternate between 30 seconds of maximum effort exercise and 90 seconds of low-intensity recovery. Repeat this cycle 8–10 times, then cool down.
- Effective HIIT exercises: burpees, jumping jacks, high knees, mountain climbers, sprint intervals, cycling sprints, or rowing bursts
- Frequency: 2–3 HIIT sessions per week (not daily — recovery is essential)
- Duration: 20–30 minutes including warm-up and cool-down
- Progression: Gradually increase intensity or reduce recovery time as fitness improves
Start at a manageable intensity and build gradually. If you have any health concerns, including high blood pressure, diabetes, or joint problems, consult your GP before beginning HIIT.
- 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.
Is HIIT alone enough for weight loss?
HIIT is highly effective but works best combined with a reduced-calorie diet. The NHS recommends approximately 500 kcal daily deficit for sustainable loss of 0.5–1 kg per week. Exercise burns calories, but dietary changes are equally important. For significant weight loss, combine HIIT with healthy eating habits. Use our free progress tracker to monitor your weight loss journey alongside exercise.
How often should I do HIIT workouts?
2–3 HIIT sessions per week is ideal for most people. This frequency allows adequate recovery between sessions — recovery is when your body adapts and becomes stronger. Doing HIIT daily increases injury risk and may reduce effectiveness. Combine HIIT with other activities like walking or strength training on other days.
Can I use HIIT if I'm significantly overweight?
HIIT can be adapted for different fitness levels, but if you're significantly overweight or have health conditions, start with lower-impact options and consult your GP first. Modified HIIT using seated or standing movements can be effective. Building fitness gradually reduces injury risk and improves long-term sustainability.
What should I eat to support HIIT and weight loss?
Focus on whole foods: lean proteins, vegetables, whole grains, and healthy fats. Eat in a calorie deficit — roughly 500 kcal below your maintenance needs daily. Adequate protein supports muscle recovery after HIIT. Consider using our free BMI calculator to understand your healthy weight range, then work backwards to calculate your calorie target.
Does HIIT work better than other exercise for weight management?
HIIT is very time-efficient but not inherently superior to other methods. Regular moderate exercise (walking, swimming, cycling) also supports weight loss. The best exercise is one you'll do consistently. Some people prefer HIIT; others prefer steady-state cardio. Combine whichever you enjoy with a healthy diet for sustainable weight management results.
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.