Training load in trail running: why elevation counts
In the mountains, pace is misleading. How to measure trail running load taking climbing and descending into account.
An hour climbing a thousand metres at 10 minutes per kilometre isn't an easy run, even if your watch says the pace is slow. In the mountains, measuring load with pace alone is misleading.
The problem
Classic rTSS compares your pace with your flat threshold pace. On a steep climb pace collapses, so the calculated load comes out very low even though you're working flat out.
The fix: grade-adjusted pace
Each section is corrected for its gradient: a kilometre at 15% becomes its equivalent flat pace. With that adjusted pace, load reflects the real effort again.
And the descents
Downhill isn't free. The eccentric work of the quads is very tiring, even when heart rate drops. That's why runs with lots of descent leave you sore even when the cardiovascular load is moderate.
In practice
- Use a tool that accounts for elevation when calculating load.
- Compare your mountain weeks and your flat weeks on the same scale.
- Without adjusted pace, heart rate is a better reference than pace in the mountains.
Traincontrol adjusts pace for gradient before calculating the load of your mountain runs.