The next run is often the signal.

Compare like with like.

Use comparable durations, terrain and effort before drawing conclusions. A single dramatic session can be useful feedback, but not a reliable trend.

Record the work that preceded the run.

The useful context is the work category, the target and the actual segment result — not an unstructured collection of health notes. That is how a split planner can show an athlete what is changing.

Adjust the goal, not just the pain.

If the target is not feasible, a helpful tool makes the trade-off visible and lets the athlete choose a safer, more credible budget. It should not disguise an unrealistic plan as motivation.