Why does my TrainAsONE heart rate target differ from my Garmin (or standard) zones?

When transitioning to TrainAsONE, many runners notice a difference between their prescribed workout heart rate targets and the standard zones set on their sports watches (such as Garmin's Zone 2).

It is important to understand that your TrainAsONE target ranges are not generic. Depending on your individual fitness level, fatigue, and running history, TrainAsONE's targets may be higher or lower than standard, percentage-based zones.

Here is a breakdown of why these differences occur and how our AI calculates your personalized targets:

1. Population Averages vs. Your Physiological Fingerprint

• Traditional Zones (e.g., Garmin): Standard zones typically rely on static, age-predicted formulas (such as 220 - age or similar estimations) to define training zones as flat percentages of your estimated maximum heart rate (HRmax).
• The Problem: Estimation formulas are highly error-prone. Two individuals of the exact same age can have widely different maximum heart rates, and even if they do, they may have significantly different metabolic thresholds (such as Aerobic and Lactate Thresholds).
• TrainAsONE's Artemis 2 Engine: Our machine-learning model completely drops population-average formulas and standard heart rate 'zones'. Instead, it performs second-by-second analysis on your real-world, historical data (pace, heart rate, perceived effort, and recovery) to build a dynamic physiological fingerprint that is entirely unique to your body.

2. Why TrainAsONE Targets Can Be LOWER than Standard Zone 2

In some scenarios, TrainAsONE will prescribe a heart rate target that feels lower and forces you to run more slowly than your watch's Zone 2 limits:

• True Aerobic Recovery: Economy runs are scheduled with the Minimum Effective Dose in mind - aiming to stimulate aerobic adaptations and promote recovery with the least amount of unnecessary strain. If the system is prioritising recovery after consecutive hard workouts, it will set a lower, safe cardiovascular 'ceiling'.
• Early Signs of Fatigue: Our AI continuously monitors subtle shifts in your data. If it detects hidden fatigue, elevated stress, or a slight decoupling of pace and heart rate, it will proactively lower your target intensity to prevent over-training and reduce injury risk.

3. Why TrainAsONE Targets Can Be HIGHER than Standard Zone 2

Conversely, fitter or more aerobically efficient runners may find that TrainAsONE schedules easy heart rate targets that are actually higher than their standard Zone 2:

• Artificially Low Traditional Zones: Standard percentage formulas often underestimate the cardiovascular capacity of a well-conditioned athlete. If you are highly fit, your aerobic threshold might occur at a higher percentage of your maximum heart rate.
• Unlocking Your True Potential: If the AI recognises that your cardiovascular system is highly efficient and that you can run at a faster pace without exceeding your aerobic threshold or accumulating metabolic waste, it will dynamically adjust your targets upward. This allows you to train productively without being unnecessarily held back by artificial, generic boundaries.

4. How to Approach Your Workouts

Because the relationship between pace and heart rate is a moving target influenced by sleep, stress, temperature, and terrain, you should adopt a hybrid approach to your training:

• For Easy & Economy Runs: Treat the upper heart rate limit as a soft safety ceiling. As long as you stay below that ceiling and your perceived effort feels genuinely easy, your run is a success.
• Never Be a Slave to One Metric: If staying within a narrow heart rate range makes your running gait feel awkward or forces you to run excessively slowly, prioritise target pace or subjective effort (RPE) instead.
• Train the AI with Run Confirmation: When you complete a run, use the Run Confirmation widget on your dashboard to rate your subjective effort (e.g., "Easy" or "Normal"). This qualitative feedback teaches the AI how your body felt, helping the model align your pace and heart rate targets faster.