Why Endurance Athletes Need a Lactate Threshold Assessment

If you’re training for Triathlon, Hyrox, or any endurance event, you may already track pace, power, heart-rate, or perceived effort, but one metric that can make a real difference is your lactate threshold. A lactate threshold assessment gives you precise, actionable data that can transform how you train, race, and recover.

What is Lactate Threshold?

Lactate threshold (LT2/LT) is the exercise intensity at which lactate begins to accumulate in the blood faster than your body can clear it. Below that threshold, your body sustains effort using mostly aerobic metabolism, with manageable lactate levels. Once you cross it, fatigue accelerates.

There are two thresholds, LT1 and LT2 (aerobic and anaerobic threshold), but for most endurance athletes what matters is knowing the intensity (pace, power, heart rate) where performance starts to become unsustainable.

Lactate Threshold Assessment using the Lactate Pro 2

Benefits of Doing a Lactate Threshold Assessment

There are many advantages of having a proper lactate threshold assessment completed. These are especially relevant if you're competing in multi-discipline or endurance events like Triathlon or Hyrox.

1. Personalised and Accurate Training Zones

   Generic heart rate or pace zones often fail to perform due to their very nature of being ‘generic’. A lactate threshold test provides individualised thresholds, so you can set training zones based on your actual physiology. That means more effective workouts.

2. Improved Endurance Performance

   Knowing LT1/LT2 helps you train just below or around it, improving your ability to sustain higher intensities for longer without fatiguing. That’s crucial for events like the bike or run legs in Triathlon, or for the varied efforts in Hyrox.

3. More Efficient Fatigue Management, Optimised Training Load, & Recovery

   With knowledge of where LT1/LT2 lies, coaches and athletes can tailor intensity more specifically. You’ll know when you really need recovery, and when you can push, helping reduce injury risk.

4. Better Race Pacing Strategy

   Because the test gives you paces or power levels tied to key physiological markers, you can plan race efforts more intelligently. You know when to push, or when to conserve your energy. For Triathlon or Hyrox, where pacing across multiple disciplines is vital, this can be a game changer. 

5. Objective Progress Tracking

   Doing periodic assessments shows improvements over time: e.g. your LT2 heart rate rises, pace or power at LT2 increases, you can sustain closer to LT2 for longer. These metrics offer more precise feedback than just “RPE” or basic pace increases. 

6. Fueling & Energy System Insights

   Testing often gives insight into how your body is using fat vs carbohydrates at different intensities. That helps fine-tune fueling strategies (nutrition/hydration) during training and races so you avoid energy crashes.

   
   

How Is an LT Assessment Done?

• Typically done in a lab or performance centre. It involves incremental stages of increasing intensity (on a bike, treadmill, or sport-specific mode), with blood lactate sampling plus measurement of heart rate, power or pace.

• Some simpler/field tests approximate LT via time trials (e.g. 20-30 minute all-out effort, then deriving threshold pace or heart rate from that). These are less accurate but useful when lab access is limited.

• The output: threshold heart rate, pace/power, providing data for individualised training zones based on your physiology.

Progressive exercise test to identify LT1 and LT2 using the stationary bike

How to Use Lactate Threshold Data in Your Training Plan

Here are some ways to apply the results:

• Build training blocks with specific threshold sessions. For example, intervals just below and just above LT2, steady threshold efforts, progressive overload.

• Adjust total volume vs intensity: more lower-intensity volume below threshold leads to endurance benefits, whereas work at or around LT2 improves speed & efficiency.

• Use lactate threshold metrics to set race‐pace goals and pacing strategy.

• Monitor improvements over time by retesting every 3-6 months or when training plateaus.

  
  

Conclusion

A lactate threshold assessment isn’t just for elite athletes, it’s a powerful tool for anyone aiming to push performance in endurance sports like Triathlon or Hyrox. With accurate lactate threshold data you train smarter, race smarter, recover better, and make measurable progress. We offer lactate threshold assessments at our performance centre, along with personalised training plan integration. Visit the link below to find out more and get booked in!

Lactate Threshold Assessment