Training load — Base, Recent, and the ratio

Training load tracks how much you're asking of your body versus what it's prepared for, to keep you building without ramping into injury.

• Base — a 42-day weighted average of your daily load (what your body is prepared for).
• Recent — a 7-day weighted average (what you've asked of it lately).
• Ratio — Recent ÷ Base. Around 1 means you're training at what you're prepared for; well above it means you're asking for more than usual.

Each session's load is duration × intensity, taken from your heart rate when it was recorded and from the session type when it wasn't — so one unrated workout never breaks the picture.

A word on what this ratio can and can't tell you. You'll see a "0.8–1.3 sweet spot" quoted widely for this kind of ratio. Treat it as a loose rule of thumb, not a law: the research behind that figure has been seriously challenged — the ratio is mathematically coupled (the same sessions appear in both halves), and the injury-risk curve drawn from it has been asked to be retracted by its critics. So Runsei does not draw a line at a number and call one side dangerous.

What it reads instead is the shape. The signal worth acting on is a sudden spike, not a high number reached by a gradual build. If your load is elevated only because you built up steadily week over week, Runsei reads that as a controlled build ("Building steadily"), not "ramping too fast."