EvoLab: Personalized Pace Zones

Zone-based training has long been a cornerstone of endurance sports, but has recently gained renewed attention recently. Zone 2 in particular has been popularized by numerous elite athletes and coaches. COROS empowers athletes with clear insights into their individualized pace zones, simplifying scientific training. Whether you’re a beginner or an elite runner, these zones enable smarter training, better recovery, and the achievement of your performance goals.

What Are the Pace Zones?

COROS pace zones help athletes train more scientifically by guiding them to run at the right effort levels for their goals. These zones split running into six clear ranges, from easy recovery runs to hard sprints, based on your lactate threshold pace (the point where your body starts to tire quickly). By using data from your runs or a fitness test, COROS sets these zones to match your current fitness, so you know exactly how fast to run for different workouts. Below, we dive into each zone with detailed insights to guide your training.

Zone 1: Recovery (Easy Effort)

• Purpose: Enhances fat metabolism and promotes recovery between intense sessions.
• Intensity: Very low, allowing comfortable breathing and conversation. This intensity can be sustained for multiple days.
• Physiological Benefits: Improves aerobic base, increases mitochondrial efficiency, and aids muscle repair.
• Use Case: Ideal for recovery runs after hard workouts or as a jog rest between intervals. Perfect for beginners building stamina or elites recovering from races.
• Example: A hike or recovery jog, keeping your heart rate low and effort relaxed.

Zone 2: Aerobic Endurance (Moderate Effort)

• Purpose: Builds your aerobic base for sustained endurance.
• Intensity: Moderate, where you can still hold a conversation but feel a steady effort. This intensity can be sustained for multiple hours.
• Physiological Benefits: Enhances cardiovascular efficiency, increases capillary density, and improves stamina for long-distance events.
• Use Case: Essential for any athlete preparing for endurance efforts.
• Example: A typical easy run or weekly long run.

Zone 3: Aerobic Power (Tempo Effort)

• Purpose: Improves your ability to sustain faster paces, ideal for marathon or half-marathon training.
• Intensity: Challenging but sustainable, where breathing becomes noticeably faster and conversation is difficult. This intensity can be sustained for 1-3 hours.
• Physiological Benefits: Boosts lactate clearance and strengthens aerobic capacity, preparing you for race-pace efforts.
• Use Case: Suited for tempo runs or steady-state efforts to mimic race conditions.
• Example: Tempo or marathon pace runs. These can also be “broken” and not a straight through tempo. For example, 4 x 10 minutes with a 2 minute jog. Many marathoners will even include this during the middle of a long run.

Zone 4: Threshold

• Purpose: Enhances endurance by training at or near your Critical Speed (10-km pace).
• Intensity: Roughly 2-5% below or above your Threshold Pace, where effort feels hard but sustainable for 30-60 minutes.
• Physiological Benefits: Increases lactate threshold, allowing you to sustain higher intensities for longer.
• Use Case: Perfect for intermediate runners aiming to improve race times or elites targeting threshold workouts. This is the zone that gets your best bang for your buck and athletes are “spamming” this zone.
• Example: Intervals at threshold pace, totaling about 30 minutes of work with short rests in between. For example, 5x6 minutes with 2-minute recovery jogs. Your main goal in this zone is to keep your effort under control.

Zone 5: Anaerobic Endurance (Very High Effort)

• Purpose: Although it does not correspond to maximal effort just yet, it applies to high-intensity training to mainly improve VO2max ability.
• Intensity: Near your VO2 max pace, sustainable for about 3-8 minutes, where breathing is labored.
• Physiological Benefits: Improves oxygen uptake and anaerobic power.
• Use Case: Critical for performance in events from 5K to 10K.
• Example: Intervals at VO2max pace, totaling about 15 minutes of work with roughly equal rest in between. Such as 5x3 minutes with 3-minute recoveries.

Zone 6: Anaerobic Power (Maximal Effort)

• Purpose: Develops sprint speed and explosive power.
• Intensity: Your all-out sprint pace, or very close to it. This intensity can be sustained for less than 3 minutes.
• Physiological Benefits: Enhances fast-twitch muscle fibers and neuromuscular coordination for sprint finishes.
• Use Case: Best for track sprinters or runners training for short, explosive efforts.
• Example: 8-minute track pyramid, such as 4x200m sprints with 90-second recoveries.

Where to View Your Pace Zones

You can access your current Pace Zones in multiple places:

• COROS Training Hub Homepage: This is the easiest location to view your most up-to-date zones.
• Within individual activities: In the post-workout summary, your watch, the COROS app, and Training Hub will all show how much time you spent in each zone.

Pace Zones in an activity summary on the COROS App

COROS Tip: Pace Zones and Effort Pace Zones use the same ranges (e.g., 6:51–7:32 per mile). Effort Pace adjusts your pace based on terrain, showing what your pace would be on flat ground for the same level of effort.

Zones Stay Fixed for Historical Accuracy

Your pace zones will update over time as your fitness changes. However, COROS does not retroactively apply new zones to old workouts. This means your activity data always reflects the zones that were current on that specific day, preserving context for training load and fitness history.

How Do We Determine Pace Zones?

Pace Zones are calculated using the Pace-Duration Model, a scientifically validated tool inspired by the Power-Duration Model used in cycling. This model analyzes your running data to derive three key parameters:

• Maximal Speed: Your fastest 1-second sprint speed, captured by COROS devices with dual-frequency GPS for pinpoint accuracy.
• Anaerobic Work: The maximum distance you can cover in 1 minute, reflecting your anaerobic ability.
• Critical Speed: Close to your sustainable 10-km or Threshold Pace, which anchors your endurance training.

These parameters, measured by data from your runs and enhanced by COROS EvoLab, enable highly individualized Pace Zones.

Coaching Insights

If you are a coach that loves to fine tune your training methods, pace zones can be very helpful in training your athlete with a more scientific approach. Pace zones are directly linked to your Running Fitness Score and Race Predictor, so when your watch detects an increase in fitness, the zones and race time predictions update too. This way, your training stays aligned with where you are today. As your fitness grows, your zones grow with you, so you always know the right pace for any workout.