Both tests happen in the lab, both involve a progressive effort, and both produce numbers you can train with. But they answer different questions. Choosing the right one starts with what you want to know.

VO2max testing answers: “How big is my engine?”
A VO2max test measures the oxygen you use as the effort increases, up to your maximum. It tells you your aerobic capacity and gives you heart-rate zones based on a measured test.
Choose it if you want: a baseline of aerobic fitness, a progress check after a training block, or a measured alternative to your watch’s estimate.
Lactate testing answers: “Where should I train?”
A lactate test takes a small blood sample at each stage of a stepped test. The resulting curve shows how your body responds to rising intensity — and where your easy, steady and threshold efforts really sit.
Choose it if you want: accurate training zones, to check whether your “easy” is really easy, or to plan race pacing.
Want both?
The VO2max + lactate test combines the two in one appointment: your aerobic ceiling and your training intensities from the same session.
Quick guide
- New to testing and want a baseline? VO2max.
- Training seriously and want precise zones? Lactate.
- Building towards a key race and want the full picture? VO2max + lactate.
- Interested in metabolic detail such as fat and carbohydrate use? Look at INSCYD.
Bike or treadmill?
Every test is available on the bike or the treadmill. Test where you train most — results are specific to the exercise mode.
Still unsure? Compare all options on our endurance testing page.
Further reading: American College of Sports Medicine.
Try it first. Estimate your VO2max with our free VO2max calculator, or work out your training zones with the zone calculator. When you want measured numbers, book a VO2max test or a lactate test in Dún Laoghaire.

