Unlocking Endurance: The Benefits of LT1 Training

When cyclists talk about training, most of the conversation revolves around FTP, VO2 max, or interval sessions. But there’s another, often overlooked, physiological marker that forms the foundation of your endurance: LT1. Training around LT1 can be one of the most powerful tools to improve aerobic fitness, endurance, and long-term performance.

What is LT1?

LT1 stands for Lactate Threshold 1. It’s the point where your body begins to produce measurable amounts of lactate, but still at a low, steady level that can be cleared without fatigue building up. Think of it as the upper ceiling of Zone 2 training.

• Below LT1 → you’re almost entirely burning fat, with minimal strain.

• At LT1 → you’re still comfortable, but now training your aerobic system at its maximum steady capacity.

• Above LT1 → lactate starts to rise more quickly, signaling the transition toward threshold and glycolytic (sugar-burning) efforts.

  
  

LT1 usually lines up with 65–75% of FTP, but depends on your fitness level and differs for each rider.  Training around this metric will enable you to ride faster for longer which is something we all strive for.

Why Train at LT1?

• Build a Bigger Engine: Riding at or near LT1 maximizes mitochondrial adaptations. This improves your ability to use oxygen and burn fat efficiently. It’s like building a larger, more fuel-efficient engine.

• Enhance Endurance: Longer rides at LT1 help your body preserve glycogen, which is essential for long events like gran fondos, stage races, or rides such as the Triple Bypass or Seattle-to-Portland. The result – you can go farther before fatigue sets in.

• Stronger Foundation: A higher power output at LT1 lets you ride faster while staying in your aerobic zone. You can maintain speed longer while conserving glycogen for when you really need it.

  
  

How to Train for LT1

• Steady Endurance Rides: Aim for 2–4 hours at the top of Zone 2 heart rate to keep it comfortable and steady (you could carry on a conversation at this level).

• Sweet Spot Workouts: Include weekly sweet spot sessions, riding just below threshold (about 84–94% of FTP). This zone delivers big aerobic gains with less fatigue than threshold work, making it one of the most effective ways to build fitness.

• Consistency over Intensity: Early in the season, focus on steady training at LT1. With 3 to 5 weeks of consistent effort, you’ll see notable improvements.

• Polarized Training Balance: Combine LT1 training with occasional high-intensity workouts to maximize aerobic development without overtraining.

How to Validate Your LT1

You can validate LT1 at home in two ways:

• LT1 Validation Testing

  • Ride 60–90 minutes at a steady wattage near your estimated LT1 power, based on a few rides at max Zone 2 heart rate.

  • If your heart rate drifts more than ~5% upward over time, or goes over max Zone 2, you’re above LT1.

  • As your LT1 improves, you'll sustain harder, faster efforts for longer.

  • Keep in mind that fatigue and stress can affect heart rate, so a coach can help interpret results and estimate LT1 power more accurately.

• Lactate Testing (Gold Standard)

  • Finger-prick lactate meters can measure blood lactate directly, with LT1 typically appearing around ~2 mmol/L.

  • This method is highly accurate, but less practical for most cyclists.

Final Thoughts

Training at LT1 may not feel glamorous – it’s not about smashing sprints or chasing KOMs – but it’s the secret sauce behind every strong cyclist. By steadily lifting your LT1, you can build a better aerobic foundation, allowing you to ride stronger, recover faster, and perform at your best when it matters most.

At Dutch Diesel Cycling, we integrate LT1-focused training into our personalized coaching plans because it builds the “diesel engine” that powers both amateurs and pros to reach their biggest goals.

Ready to determine your LT1 and improve endurance? Reach out – we’ll help you validate your LT1 and structure a training plan for sustainable, long-term gains.