What RPE is and how to calculate training load

What perceived exertion measures

RPE stands for rating of perceived exertion: the score an athlete gives to what they have just done. It does not measure what happened outside — the kilometres, the kilos, the minutes — but what it cost inside.

That distinction is what makes it useful. Two players can cover the same distance in the same match and finish in completely different states, depending on how they slept, what they were carrying and where they are in the season. GPS records the first; RPE, the second.

The Borg CR-10 scale

The most widely used scale here is Gunnar Borg’s CR-10, running from 0 to 10: 0 is complete rest and 10 the hardest effort that athlete can sustain. The intermediate values carry verbal anchors — easy, hard, very hard — which help keep the rating stable over time.

It is worth explaining it properly once, at the start of the season, and then leaving it alone. A squad that understands the scale gives comparable numbers; one that has it changed mid-year does not.

From a rating to a load

The step is multiplying the RPE by the session duration. That product, known as session load or session-RPE and associated with the work of Carl Foster, turns a perception into a figure you can add up.

Ninety minutes at RPE 8 is 720 arbitrary units. Sixty minutes at RPE 5 is 300. The scale has no physical unit: 720 is not 720 of anything in particular. Its value is relative, and that is enough to compare sessions, sum them by week and follow one athlete across months.

The detail most often missed is individual minutes. In a football match, eleven play ninety minutes and the rest come on for twenty or not at all. Using the match length for everyone distributes a load that never happened.

When to ask for it

About thirty minutes after the session ends. Asked immediately, in the changing room and still breathing hard, the end of the session dominates the answer: one demanding set at the close tilts the number even if the rest was easy.

The other common mistake is the coach filling in the RPE. If the person who planned the session enters the number, it stops being a measurement and becomes an expectation — and the very information we were after, the gap between planned and experienced, disappears.

What comes next

With several weeks logged, things appear that a single session cannot show: how much load each athlete accumulates, how similar the days are to each other, and how the current week compares with the recent average.

None of that requires equipment. It requires consistency, which in practice is the hard problem: twenty athletes answering every day, without anyone forgetting.