Metabolic Test (VO2Master FIT upload)

What this assessment is

The Metabolic Test flow takes a FIT file from a VO2Master device (or compatible portable metabolic cart), parses it, and produces a structured metabolic report: VT1, VT2, VO2max, gross efficiency, plus interactive charts. The result is saved as an Assessment and individual metrics flow into MetricHistory.

URL: /tools/metabolic-test/.

Inputs the form asks for

• Athlete (selected from your roster).
• Test date.
• FIT file (.fit or .fit.gz) from a VO2Master test session.

What the parser computes

• Test type detection: ramp vs acyclic (steady-state).
• VT1 (aerobic threshold): the first ventilatory turn point.
• VT2 (anaerobic / lactate threshold): the second ventilatory turn point.
• VO2max: peak VO2 reached.
• Gross efficiency (if power data is in the file).
• Per-stage averages for VO2, HR, RER, VE, RR, and power if available.

What you see after parsing

• A summary card with the four headline numbers.
• Interactive charts: VO2 over time, HR over time, RER over time, breath-by-breath stream.
• Stage-by-stage table for ramp tests.

Coach review and save

The flow has two phases:

1. Upload + analyse: the parser produces a report. You review the values inline.
2. Save: confirm the coach-reviewed VT1 / VT2 / VO2max / efficiency values (you can adjust them if the auto-detect put a turn point in a debatable spot), then save.

On save:

• An Assessment record of the matching type is created.
• MetricHistory rows are written for VO2max, gross efficiency, and any thresholds you confirmed.
• The metrics flow into the athlete's analytics pages and feed downstream calculators (CdA's altitude assumptions, fueling calculator's intensity scaling).

Why review before save

Auto-detected VT1 and VT2 are reliable for clean ramp tests but the algorithm can place a turn point on the wrong inflection if the test had a noisy stage or the ramp rate was unusual. The save-after-review pattern keeps the coach in the loop for the values that matter.

When to test

Most coaches run a metabolic test:

• At the start of a new training relationship.
• Once or twice a year as a fitness benchmark.
• After a structural training change (e.g. switching from threshold-heavy to polarised) to see how the metabolic profile shifted.

See also: Logging an assessment overview, Race readiness checklist.