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Lactate Analysis Demo

Try every feature with sample data. No registration required.

📝 Enter Test Data

Enter your measurements here.

Test Date

Max Heart Rate (HRmax)

Your maximum heart rate. Required for calculating heart rate zones.

Resting HR

Your resting heart rate in the morning while lying down. Required for Karvonen formula (HRR). Default: 60

Stage Duration (min)

Duration of each exercise stage in minutes. ≥5 min recommended for lactate steady-state (Heck et al. 1985). Below 4 min, lactate values are systematically underestimated.

Body Weight (kg)

Optional. Used for: relative power (W/kg), VO₂max estimation, and relative carbohydrate consumption (g/kg/h).

Gender

Sample Site

Fingertip values are systematically ~0.5–1.0 mmol/L higher than earlobe values (Dassonville 1998, Zhong 2024). Never switch sites — consistency is key.

6 Stages active•Step size: +20W

Complete: 6/5|5 Stages = Minimum|6 Stages = Best validation ⭐

Power (W)

Power in Watts. After entering the first stage, others will auto-fill with +20W/stage.

Heart Rate (bpm)

Heart rate at the end of the stage (after 3 min effort).

Lactate (mmol/L)

Lactate value in mmol/L, measured at the end of the stage (e.g. with Lactate Pro).

Stage 1

Watt

HR (bpm)

Lactate

bpm

mmol

Stage 2

Watt

HR (bpm)

Lactate

bpm

mmol

Stage 3

Watt

HR (bpm)

Lactate

bpm

mmol

Stage 4

Watt

HR (bpm)

Lactate

bpm

mmol

Stage 5

Watt

HR (bpm)

Lactate

bpm

mmol

Stage 6

Watt

HR (bpm)

Lactate

bpm

mmol

Analysis Results

Test QualityR² = 1.000

100%Excellent

Test Coverage

Complete

Note: Modified Dmax slightly overestimates MLSS (+10 W / ~0.4 mmol/L). For best agreement with MLSS, Caen 2021 (Eur J Appl Physiol) recommends the expert LT2 method.

Aerobic Threshold (LT1)

199 W±16 W

139 bpm(73% HRmax) • 1.5 mmol/L

Accuracy: ±10–15 W (day-to-day biological variation + device error + method scatter)

Start of lactate rise. Purely aerobic metabolism (fat burning) up to this point. Ideal for long, easy training (Zone 1-2). Note: LT1 is algorithmically derived from the LT2 method and not independently validated (Faude et al. 2009).

Anaerobic Threshold (LT2)

248 W±17 W

161 bpm(85% HRmax) • 3.2 mmol/L

Accuracy: ±10–15 W (day-to-day biological variation + device error + method scatter)

An estimate of your individual anaerobic threshold — an approximation of the Maximum Lactate Steady State (MLSS). The true MLSS varies between individuals and does not sit at a fixed lactate value; only an MLSS constant test gives the gold standard. The "threshold" for tempo training.

Enter body weight to estimate VO₂max.

Lactate Curve

AI Interpretation

## 🤖 Demo Analysis

Strengths & Weaknesses

The ratio of LT1 to LT2 indicates a solid aerobic base. Your VLamax appears to be in the moderate range.

Training Recommendation

Focus on polarized training. 80% base training (Zone 2), 20% high intensity (Zone 5).

Weekly Schedule Idea

* Mon: Rest day

* Tue: Intervals (4x8min at threshold)

* Wed: Easy run

* Thu: Tempo changes

* Fri: Swim/Core

* Sat: Long run (Zone 2)

* Sun: Bike ride or easy run

Training Zones

LT1-anchored zones

Zones anchored to LT1: your Z2 upper bound sits at 80% of your LT2 — exactly where your step test shows the first lactate rise. This is the physiologically correct Z2 boundary (San Millán & Brooks 2018), not a fixed Coggan percentage. Guarantees that Z2 sessions stay in the fat-oxidation range.

Zone 1•Recovery

Active recovery, very easy training

< 169 W

< 68% LT2

Zone 2•Base 1

Fat metabolism, long duration

169 - 199 W

68%–80% LT2

Zone 3•Base 2

Tempo run, Sweet Spot

199 - 223 W

80%–90% LT2

Zone 4•Threshold

Threshold training, intervals

223 - 261 W

90%–105% LT2

Zone 5•Peak

VO2max, Anaerobic capacity

> 261 W

> 105% LT2

Note: Zones are LT2-referenced (not FTP). Coggan's FTP ≈ Critical Power ≈ ~95% VO₂max power, typically 10–15% above LT2. Zone 4 therefore targets the MLSS range, not above it.

Race Prediction

40 km (OD)

248 – 258 W

100–104% FTP

90 km (MD)

199 – 209 W

80–84% FTP

180 km (LD)

174 – 184 W

70–74% FTP

Based on LT2. Individual variations possible.

VLamax Metabolic Profile

⚠️ Heuristic – not physiological modeling: VLamax from step test is an approximation rule based on lactate slope, not a validated physiology model. Error margin ±15–25% (optimistic); up to ±40% with unfavorable protocols. Mader's original model requires simultaneous VO₂max measurement. For precise VLamax: 15-s all-out sprint (Mader method; Wackerhage 2022; Meixner 2025).

0.88mmol/L/s

0.66–1.10 mmol/L/s (±25% range)

Very High≈ Heuristic (±25%)

Limits empirical according to Mader model (Wackerhage 2022). No published norm values.

Athlete Type

Sprinter Type

EnduranceBalancedPower

Maximum anaerobic capacity. Sprints, short distances, explosive efforts.

Energy Consumption @ LT2

Calculated at LT2 intensity (~85% VO2max). This is your steady-state threshold pace – sustainable for longer periods. At race pace above LT2 (e.g., 10k), consumption is significantly higher!

Carbohydrates70g/h

Carbohydrates: 75%Fat: 25%

Based on the crossover concept (Brooks & Mercier 1994, Romijn 1993). Nutritional status and temperature can shift actual rates by a factor of 2–3 (Burke 2011).

Training Recommendations based on VLamax

🚴 Long Endurance Sessions (Zone 2)

Train regularly 2-4 hours in Zone 2 to lower VLamax and improve fat metabolism.

2-3x per week

🍽️ Fasted Training

Easy sessions in the morning without carbs to promote fat adaptation.

1-2x per week

⏸️ Reduce Sprints

Fewer high-intensity, short intervals, as they increase VLamax.

Max 1x per week

🎯 🎯 Your Personalized Pacing

Target IF

Intensity Factor: Your target pace relative to your FTP/threshold. 100% = threshold pace, >100% = above threshold.

88%≈ 219 W ±15 W

Carbs/Hour

Theoretical carb consumption at race intensity. For short events (<1h), intake is not needed as glycogen stores suffice. For longer events (>1h), this shows the recommended intake.

30g

VLamax:0.88

IF Range: 85% – 95%

Unsicherheit propagiert aus LT2-Bootstrap-CI (linear via IF-Multiplikation)

IF-Quelle: Allen & Coggan 2019, „Training and Racing with a Power Meter" (3. Aufl.)Kohlenhydrate: Jeukendrup 2014 (30–75 min: optional bis 30 g/h)

Race Strategies

Zone 4

~1h

Time Trial (40km)

Exactly at FTP. Pure threshold effort.

Training Recommendations

Focus:Pacing & Holding Aero Position

Key Session 1:2x 20min @ 95-100% FTP (Rest: 5 min)

Volume:Lots of "Sweet Spot" training (88-93% FTP)

Progression Tracking

Start

230 W

08/01/2026

Current

240 W

10/01/2026

Change

+4.3%

2 Days

Lactate Analysis Demo

📝 Enter Test Data

Analysis Results

Aerobic Threshold (LT1)

Anaerobic Threshold (LT2)

AI Interpretation

Strengths & Weaknesses

Training Recommendation

Weekly Schedule Idea

Training Zones

Race Prediction

VLamax Metabolic Profile

Energy Consumption @ LT2

Training Recommendations based on VLamax

🚴 Long Endurance Sessions (Zone 2)

🍽️ Fasted Training

⏸️ Reduce Sprints

Sprint VLamax Calculator (Mader Method)
The gold standard for VLamax determination. Perform a 15-20 second all-out sprint and measure lactate before and after.

🎯 🎯 Your Personalized Pacing

Race Strategies

Time Trial (40km)

Training Recommendations

Progression Tracking

Like the app?

Lactate Analysis Demo

📝 Enter Test Data

Analysis Results

Aerobic Threshold (LT1)

Anaerobic Threshold (LT2)

AI Interpretation

Strengths & Weaknesses

Training Recommendation

Weekly Schedule Idea

Training Zones

Race Prediction

VLamax Metabolic Profile

Energy Consumption @ LT2

Training Recommendations based on VLamax

🚴 Long Endurance Sessions (Zone 2)

🍽️ Fasted Training

⏸️ Reduce Sprints

Sprint VLamax Calculator (Mader Method)The gold standard for VLamax determination. Perform a 15-20 second all-out sprint and measure lactate before and after.

🎯 🎯 Your Personalized Pacing

Race Strategies

Time Trial (40km)

Training Recommendations

Progression Tracking

Like the app?

Sprint VLamax Calculator (Mader Method)
The gold standard for VLamax determination. Perform a 15-20 second all-out sprint and measure lactate before and after.