FAQ ~ SH1TS Variances
SH1TS ~ Why are my figures all over the place?
Ahhh yes, these sessions, as you will find, are aptly named. But when you crack 'em, the rewards are worth it. I keep telling myself!
It's the session's cumulative fatigue that gets you. And the decreasing rest periods. These sessions target the bottom, middle and top of your anaerobic capacities and stretch you in many physical and mental directions all at the same time.
There are no prescriptive figures, because there can't be. We don't all fit the nice, theoretical, sport scientist's performance curve.
Individual riders, with the exact same FTP number, could bang out completely different wattages for these intervals. One could be higher for the "long" intervals but behind on the short, and vice-versa. It really is very individualistic.
For instance, two riders that can both bang out 250 watts for 7 minutes, might have outputs of 275 and 290 for 5 minutes. But the same riders could, respectively, put out 350 and 335 for three minutes.
The balance shift isn't always linear, and the "power advantage" isn't always with the same rider across the whole spectrum.
Some riders try to compare power figures with each other. But without knowing the other riders weight, BMI, cardiac output, lung capacity, mitochondrial density, lactate threshold, and a myriad of other physiological variables, power numbers can easily mislead.
You can also see why we don't use heart rates when you look at the graph above (yellow power, red heart). The heart rate just about tops out as we get to the end of the interval, although we've been on the gas for quite some time.
Individual riders, with the same resting and max heart rates, will return completely differing cardio numbers across the boards for these sessions.
Again, it all depends on heart & lung size, and efficiency, cardiac output, heat build up on the turbo, hydration, and so many other factors this page isn't big enough to explain them all.
Sorry for the long explanation! But in a nutshell, you just go as hard as your body will allow you to, to just finish the last interval.
The numbers will be what they will be. As long as you do your best, you will improve, no matter what the numbers are.
Your job, is to find the output that's right for you. A voyage of discovery, but one worth taking.
Here's the few power traces of how the the sessions work..
Above is the power file for the SHITS A
Above is the power file for the SHITS B
Above is the power file for the SHITS C
as you can see too optimistic at the start and died on number 5!
It won't take a genius to notice why I never train with a heart rate monitor ~ the red line!
And here is a power distribution file showing how sessions such as this can target your training right where it's needed. As long as you're targeting VO2max that is. But who isn't?