Training load for running: rTSS
How to measure the load of your running workouts using pace: what rTSS is and why threshold pace is the key.
In cycling, load is measured with power. In running, the most widespread reference is pace, and that's where rTSS comes from: TSS calculated with pace.
How it works
The pace of each section is compared with your threshold pace, the one you could hold for about an hour. Running a full hour at that pace equals 100 points.
Threshold pace is everything
If your threshold pace is wrong, all your load is wrong. With a threshold that's too slow, any easy run looks like a hard session; with one that's too fast, intervals barely add up.
- Review it every few months or after a good race.
- A 10 km race or a 30-minute test gives good estimates.
Its limits
Pace knows nothing about hills, wind or heat. On flat ground it works very well; in the mountains, pace has to be adjusted for gradient, because climbing at 8 minutes per kilometre can cost more than flat running at 5.
When pace doesn't work, heart rate is the alternative. What matters is always using the same reference so weeks are comparable.