Performance
    Strong Evidence

    Lactate Threshold Increase

    The highest sustainable intensity before blood lactate accumulates faster than it can be cleared — the practical ceiling on endurance performance.

    TL;DR

    Lactate threshold is the intensity at which lactate production outpaces clearance. It predicts endurance performance better than VO2max does, and it is far more trainable — moved mainly by high-volume easy training plus targeted threshold work, with buffering supplements offering a small additional edge.

    Why It Matters

    Two athletes with identical VO2max can differ by many minutes over a half marathon because of where their threshold sits as a fraction of that maximum. Threshold reflects mitochondrial density, capillarisation, monocarboxylate transporter expression and fibre type recruitment — all adaptations that keep improving for years after VO2max has plateaued. It is the metric that best tracks real endurance progress in trained athletes, and it also has metabolic health relevance, since lactate clearance capacity tracks mitochondrial function and insulin sensitivity.

    How to Measure

    Gold standard is a graded exercise test with capillary blood lactate sampled at each stage to identify LT1 and LT2. Practical field alternatives include a 30-minute time trial where average heart rate over the final 20 minutes approximates threshold heart rate, critical power testing on a bike, or a portable lactate meter used during a step protocol. Retest every 8-12 weeks, since threshold pace drifts as fitness changes.

    Biomarkers

    Blood lactate at fixed workloads
    Threshold heart rate and pace or power
    Functional threshold power (FTP)
    Ventilatory threshold from gas exchange
    Running economy (mL O2/kg/km)
    Resting heart rate variability as a load marker

    Optimization Protocol

    Build the aerobic base first: 70-80% of weekly training volume below LT1, which drives mitochondrial biogenesis and capillary density without accumulating fatigue. Add two weekly threshold sessions — 2 x 20 minutes at LT2, or 4-6 x 8 minutes with short recoveries — and progress duration before intensity. Include one weekly session above threshold to raise the ceiling. Support with adequate carbohydrate availability during hard sessions, iron repletion if ferritin is low, and beta-alanine loading at 4-6 g/day, which buffers hydrogen ions and has consistent small effects in the one-to-ten-minute domain. Sodium bicarbonate at 0.2-0.3 g/kg is an acute alternative for race day. Expect measurable change over 8-12 weeks.

    Lifestyle Levers

    • Polarised training distribution with most volume easy
    • Two structured threshold sessions per week
    • Adequate carbohydrate intake around key sessions
    • Correcting iron deficiency, which limits oxygen delivery
    • Sleep of 7-9 hours to support adaptation
    • Heat and altitude exposure as advanced stimuli
    • Avoiding chronic accumulation of moderate-intensity work

    Supporting Supplements

    Supporting Research

    Frequently Asked Questions

    Typical Timeframe

    Measurable improvement in 6-8 weeks of consistent training; substantial gains over one to three seasons

    Measurable Metric

    Power or pace at maximal lactate steady state, and threshold as a percentage of VO2max

    Research Summary

    Studies4
    Supplements1
    Evidence
    Strong Evidence

    My Notes

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    This information is for educational purposes only. Always consult a healthcare professional before starting any supplement regimen.