You can't manage what you don't measure
Why managing training load with data instead of feel makes the difference, and where to start.
Performance begins with knowing the difference between feeling good and going well. A coach's eye is valuable, but what the eye sees doesn't always tell you what the load actually is. You can't consistently manage what you don't measure.
Load comes in two kinds
Think about training load in two layers:
- External load, the work itself: distance, weight, reps, speed.
- Internal load, the athlete's response to that work: heart rate, perceived effort, recovery.
The same external load produces very different internal load in two athletes. Build the plan on external load without watching internal load, and you sharpen one athlete while grinding down another.
What to measure
You don't need a complex lab. Consistent, simple data beats sporadic, rich data:
- Perceived effort (RPE) and duration per session.
- Weekly total load and sudden spikes.
- One simple recovery marker, sleep, resting heart rate, or a short vertical jump test.
The goal isn't to reduce the athlete to a number; it's to move decisions from guesswork to observation.
Where to start
The most common mistake is trying to measure everything at once and quitting by week two. Pick one metric, collect it consistently for four weeks, then add one more. Once measurement becomes a habit, the plan starts resting on evidence.
Working evidence-led isn't about more data; it's about meeting the right data with the right question.