MTB Power Conversion

TBiking

New to power training and putting together winter/spring training and planning to be pretty attentive to CTL, but have one issue. I am training to race MTB and keep at least one day for MTB specific training (no Power Tap). Does anyone have a rough estimate of TSS ( or any way of determining) per hour? I realize effort is the key so lets say pretty solid effort which if I had to guess in an effort to convert to road watts ( and this is a very rough estimate ) I would say around 200 - 220 watts for endurance pace and I will be putting in some harder efforts which might eguate to 300 for 20 min intervals. I also realize that the effort will be much more up and down then on the road and will effect other numbers.

Thoughts?

Woofer

It depends on the terrain you train on and the length and intensity of the ride...
Most of my MTB rides with a PowerTap are much easier as measured by TSS and AP and NP versus any road ride, however the perceived exertion is much higher.

jbvcoaching

Estimate IF, and you can measure duration.

TSS = IF^2 * duration (in hours) *100

When I first got cyclingpeaks, I'd play 'guess the IF' before every download. PE being pretty reliable and all, I was (and still am) usually within a couple hundredths.

strader

Here's how I do it: For typical mtb racing and race pace rides I figure low end of L4 for power (91% ftp). For fast training rides I figure low end of L3 (76% ftp). For easy mtb rides like with a group of slower riders with lots of short breaks and easy spinning I use low end of L2 for power (56% ftp). For something really intense like a 30 minute short track race use 100% of FTP.
So TSS would work out like this:
Short track race: 100 TSS/hour
mtb race: 83 TSS/hour
solo training ride, endurance pace: 58 TSS/hour
Group ride with slower riders and lots of stops: 32 TSS/hour