Worried about your Chester step test?
Get your true VO2 max measured in our Aberdeen lab. Unlike a step test, which estimates your fitness from your heart rate, we measure the oxygen you actually use. For offshore and ERT medicals, firefighters, divers and other safety-critical roles. Verified results on the day.
Treadmill walk, run or bike. Results document before you leave.
Why step tests can get it wrong
The Chester step test is quick and widely used, but it doesn't measure your fitness directly. It predicts your VO2 max from how fast your heart rate rises while you step. Anything that pushes your heart rate up can pull your score down, even if you're fit enough for the job.
Nerves and adrenaline
Medical-day nerves raise your heart rate before you even start stepping.
Caffeine, sleep and heat
A strong coffee, a short night or a warm room can all lift your heart rate and lower your estimate.
Medication and build
Some medications affect heart rate, and step height suits some body sizes better than others.
Measured, not predicted
A direct test measures the oxygen you use, so your result reflects your real fitness.
Know the number you need
Standards vary by role and employer, so always check yours. These are some of the most common.
Offshore ERT (OEUK)
At least 35 ml/kg/min for men and 33 ml/kg/min for women under the OEUK Medical Guidelines (Issue 8, 2025), usually assessed by the Chester step test.
Commercial divers
A commonly cited benchmark of 40 ml/kg/min for HSE diver medicals.
Fire and rescue
42.3 ml/kg/min is the National Fire Chiefs Council entry standard, often assessed with the Chester treadmill test.
Built for safety-critical roles
Offshore and subsea
Emergency response team members, breathing apparatus wearers, deck crew and anyone needing an OEUK or company fitness standard.
Firefighters
Applicants and serving firefighters preparing for Chester treadmill or step test assessments.
Commercial divers
Divers needing aerobic fitness evidence for their initial or annual medical.
Wind, maritime and employers
Technicians and crews with fitness standards, and employers who want accurate testing for their teams.
Medical VO2 max testing options
No hidden costs, no referral fees. Verified results on the day.
Occupational VO2 Max Test
A direct, verified VO2 max result for your medical.
£150
Per test
- Direct VO2 max test on a treadmill or bike (walking test available)
- Oxygen use measured, not estimated
- Verified results document on the day
- Training zones and aerobic fitness report
12-Week Preparation and Retest
Test, train and retest so you arrive at your medical knowing you'll pass.
£449
Includes your retest
- Baseline VO2 max test so you know where you stand
- Personalised 12-week plan built around your target score
- Monthly coaching check-in and plan adjustments
- Pre-medical retest to confirm you've hit the standard
48-Hour Fast-Track Test
For when your medical or mobilisation date is close.
£225
Per test
- Everything in the standard test, plus:
- Guaranteed appointment within 48 hours
- Priority slot around your medical date
- Call 01224 900500 to confirm availability
Testing a team? We test groups for employers and training providers. Get in touch or call 01224 900500.
Check what your medical accepts
Each employer and medical examiner sets their own rules on which fitness tests they accept. Before booking, check with your OEUK medical examiner, occupational health team or employer that a direct VO2 max test meets their requirement.
Whatever they need, knowing your real VO2 max tells you whether you're ready, and how much work you need to do if you're not.
Chester step test and medical VO2 max FAQs
Is this an alternative to the Chester step test?
It's a more accurate way of measuring the same thing. The Chester step test estimates your VO2 max from your heart rate; our test measures the oxygen you actually use. Medical guidelines and employers set their own rules on which tests they accept, so check with your medical examiner or employer before booking. We give you a detailed, verified report to take with you.
I failed my Chester step test. What should I do?
First, don't panic. Step tests estimate VO2 max from heart rate, so nerves, caffeine, poor sleep, heat or some medications can push your heart rate up and your estimated score down. A direct VO2 max test shows your true fitness. If you are genuinely below the standard, our 12-week preparation package gets you there with a plan and a retest.
What VO2 max do I need for an OEUK ERT medical?
Under the OEUK Medical Guidelines (Issue 8, 2025), emergency response team members need an aerobic fitness of at least 35 ml/kg/min for men and 33 ml/kg/min for women, normally assessed with the Chester step test. Standards can differ by role and employer, so always confirm the requirement for your job.
What VO2 max do firefighters need?
The National Fire Chiefs Council entry standard is 42.3 ml/kg/min, and many services assess it with the Chester treadmill walk test. Check the exact requirement and test with your service.
How is a direct VO2 max test different from a step test?
You walk or run on a treadmill (or ride a bike) while wearing a mask that measures the oxygen you breathe in and the carbon dioxide you breathe out. The effort increases gradually and we record your actual oxygen use, rather than predicting it from your heart rate.
How quickly do I get my results?
On the day. You leave with a verified results document showing your measured VO2 max, ready for your medical.
Can I book at short notice?
Yes. Our 48-hour fast-track option guarantees a test within two working days, for when your medical or mobilisation date is close.
How should I prepare?
Avoid hard exercise for 24 hours, caffeine and heavy meals for at least two hours beforehand, and bring trainers and comfortable kit. Tell us about any medication when you book, especially anything that affects your heart rate.