What Is VLaMax?

If FTP is the number most athletes obsess over, VLaMax is the one that quietly explains why two people with the same FTP can respond to completely different training. It rarely gets tested, mostly because it rarely gets explained well.

What VLaMax actually measures

VLaMax stands for maximal lactate production rate — essentially, how fast your body can produce energy anaerobically, through glycolysis, when the demand is high. It's not a fitness score and it isn't inherently good or bad to have a high or low value. It's a description of your metabolic profile: how much of your power comes from the fast, glycolytic system versus the slower aerobic system.

Why two athletes with the same FTP can need different training

Picture two riders who both hold 280 watts for an hour. One gets there mostly through a huge aerobic engine and a naturally low VLaMax — think of a strong time trialist. The other gets there with a smaller aerobic base but compensates with high anaerobic contribution — closer to a track sprinter's profile. Test them on a 5-minute effort or a sprint and the difference becomes obvious, even though their FTP looked identical on paper.

Train them identically and you'll get uneven results. The low-VLaMax rider usually needs more top-end and anaerobic work to round out their profile; the high-VLaMax rider usually needs more sustained aerobic volume, and often benefits from deliberately lowering VLaMax to raise their aerobic ceiling.

How it's tested

VLaMax is typically derived from a short maximal effort (around 15–30 seconds) paired with a longer threshold-adjacent test, comparing lactate accumulation and power output between the two. It's not something you estimate from a single ramp test — it needs its own dedicated protocol, usually alongside a lactate threshold test.

What to actually do with the number

A high VLaMax with a race focus on longer, steadier events (gran fondos, longer TTs, most triathlon distances) usually points toward more low-intensity volume and specific work to suppress excess glycolytic contribution. A low VLaMax with a focus on shorter, punchier events (criteriums, short XCO laps, sprint finishes) usually points toward more high-intensity, anaerobic-specific sessions. Context — your event, your strengths, your training history — decides how to act on the number, which is exactly why it's tested and interpreted alongside everything else in a performance profile, not read in isolation.