I've been asked by a number of athletes lately about PMC charts, and TSS. A lot of athletes use PMC charts and combine everything. I know a number of athletes using PMC charts with TSS scores estimated for strength training sessions, swimming, and more.
One athlete I spoke with was asking me, "How much of a TSS should a workout be over CTL, by percentage, to be counted as too much, too little, or just right?"
But let me clarify something which many athletes miss, that all TSS points are not equal from sport to sport. For the purposes of simplicity, let's define each sport and their TSS.
rTSS = TSS points from run workouts
bTSS = TSS points from bike workouts
sTSS = TSS points from swim workouts
I will not even begin to mess with strength training here. Too many variables.
1 rTSS does not equal 1 bTSS nor 1 sTSS, and that is universally true for each sport. Think of it in terms of how you would feel the day after a 100 TSS session, which is 1 hour all-out effort, (FTP).
100 rTSS = This is like racing a 10K or even a half marathon for some athletes! You'll likely be very sore the next day, and running hard again is probably a few days away, at least. Push the envelope a little too soon and injury is just around the corner. The weight bearing aspect of running really beats the body down.
100 bTSS = You could easily go out and do a bike ride the next day, and even race fairly well. Heck, the Tour de France proves this! The athletes hit over 100 bTSS on an almost daily basis.
100 sTSS = You could easily do a 100 sTSS swim in the AM, and come back and put in another big swim set in the PM. The medium of water helps to keep the physically damaging stress at bay.
In the end, if you're combining PMC charts, that's fine, I do it with bike and run, never with swim, (I will explain that in another post.) However, if your goal is to exceed a certain TSS over your combined CTL, this is a bad idea, because the physical weight of the TSS must be considered, or you're likely headed to injury.
For example, if your bike CTL is 100, run CTL is 45, and your swim CTL is 80, for a combined CTL of 225 TSS/day, and you're going to do a big run workout where you want to get 10% more than your combined CTL, then you're doing a run of nearly 250 TSS!!! That's a HUGE workout.
Consider instead the individual PMC charts and where each sport is at in terms of CTL. 10% of your current CTL for rTSS is a lot different, as that would be a 50 TSS workout in this instance, and that's totally doable. 30 percent would be 60, which is also fair and conservative at a 45 CTL.
It's fine to monitor total load, ATL especially, with a combined PMC chart of many sports, but be careful about judging individual sport workouts on that combined PMC's CTL, as the TSS values are not anywhere near equal from sport to sport.