Analyze lactate curve: what the shape means

The expected overall shape

The German guide describes a low opening section, a gradual increase and a steeper rise at higher workloads. That overall shape provides the basis for Dmax, Modified Dmax and Dickhuth methods; it need not be a perfectly smooth exponential curve.

A flat curve has more than one explanation

A long flat opening can indicate effective production and clearance. It can also mean the test ended before the threshold region. The source notes that a highest value below 3 mmol/L may not have covered LT2, so a flat curve alone is not proof of exceptional fitness.

Assess the rising section

The article favors several points before, around and after the threshold, including at least two measurements in the rising region. One high final reading is less stable.

• No clear rise: check whether the test ended too early
• High opening values: check an overly hard first stage
• Abrupt isolated jumps: check sample quality
• Several coherent rising points: a more interpretable threshold region

Compare methods and investigate disagreement

Outliers and curve shape can affect a single method. LactateThreshold presents several threshold models together. Closely grouped results offer a different level of confidence from widely scattered results, which are a reason to examine the protocol and measurements.