How do you quantify the standard or exertion of a exercise? Relating to coaching metrics, most applications will calculate this utilizing TSS or the Coaching Stress Rating. There are numerous issues TSS represents in a exercise and plenty of misconceptions inside the endurance neighborhood about this metric. So what does all of it imply?
What’s TSS?
TSS is an estimate of the coaching load created by a exercise based mostly on depth and length.1 TSS is calculated by utilizing each IF (depth issue) and time, to find out how “laborious” a coaching session was based mostly on the magnitude of the physiologic diversifications to coaching. In easiest phrases, TSS determines the “price” a exercise has had in your physique. Sometimes the upper the calculated TSS rating, the extra fatigued you’ll really feel.
How is TSS Calculated?
Metrics Breakdown:
For a extra in-depth clarification of biking, metrics go to The Metrics that Matter. For a fast evaluation, take a look at the next components which are concerned in TSS calculation beneath:
TSS is calculated by the next equation:
TSS = (sec x NP x IF) / (FTP x 3600) x 100
sec: the full variety of seconds within the session
NP: Normalized Energy (extra on this in a bit)
IF: Depth Issue (extra on this in a bit)
FTP: Purposeful Threshold Energy (energy you’ll be able to maintain for the 60-minute length)
3600: complete variety of seconds in an hour
For instance, a 60-minute experience at FTP (purposeful threshold energy) would yield a TSS rating of 100.
Holding this in thoughts, it is usually essential to tell apart that not all TSS scores are the identical. What can we imply by this? Since length and depth are each utilized in calculating TSS, you’ll be able to go for a 3-hour straightforward experience and have your TSS equal to a 90 minute VO2 max interval session, however one in all these periods leaves you extra bodily exhausted than the opposite. Why is that? It’s not that the metric is flawed, however the way in which we strategy TSS is skewed. Not all TSS numbers are created the identical, and we can not at all times view the identical quantity as that means the identical sort of depth effort. In your straightforward lengthy experience, you had been taxing a distinct power system than you had been whenever you did your VO2 max repeats. One session allowed you to stay in Zones 1 and a couple of on your coronary heart charge, whereas the opposite had you drifting into Zone 5 all through a number of intervals. So whereas every exercise was taxing in its personal proper, the identical rating didn’t signify the identical quantity of restoration wanted post-sessions.
Energy and Coronary heart Charge Based mostly TSS
Energy-based TSS coaching is the default methodology of calculation for biking. To ensure that power-based TSS to be correct, this requires you to have an FTP (purposeful threshold energy) calculated after which energy zones set based mostly on this. When you wouldn’t have power-based metrics and use coronary heart rate-based coaching, this could nonetheless be used to calculate TSS.
Coronary heart charge TSS or hrTSS is a much less correct mannequin for figuring out your TSS of a exercise. Whereas hrTSS is correct when performing steady-state efforts, or endurance rides, it’s far much less correct when intervals come into play. hrTSS is predicated on time spent in every coronary heart charge zone based mostly in your Threshold Coronary heart Charge. When there are giant or frequent fluctuations in your coronary heart charge information, equivalent to information post-interval session, it’s laborious for an correct TSS to be quantified from this because it takes time on your HR to stabilize pre, throughout, and publish effort.
When you wouldn’t have an influence meter, or for instance are attempting to find out TSS for an exercise that’s not coronary heart charge or power-based, then utilizing RPE is an effective estimate to gauge your TSS for an exercise. You will want to gauge the perceived exertion of the exercise after which issue within the length of the exercise as properly.
TSS and 4DP
How does TSS relate to your 4DP energy profile? With 4DP, the exercises are individually tailor-made based mostly in your means to supply energy above FTP. For shorter more durable efforts, the facility targets will be drastically totally different even when these two riders have the identical FTP.
For instance, 2 riders each with an FTP of 200W. Rider 1 can maintain 500W for 1 minute, Rider 2 can maintain 350W for 1 minute.
Having each riders do 5 x 1-minute repeats at 150% of FTP (300W) would give equivalent IF/TSS values since their FTPs are the identical.
Nonetheless, Rider 1 will discover this exercise a lot simpler than Rider 2.
Having the riders do 5 x 1-minute repeats at 90% of 1-minute energy (450W and 315W respectively) will successfully make the session equally “laborious” for each riders, although Rider 1 can have a a lot greater IF and TSS for this session.
TSS and your Coaching
TSS is an effective software to make use of for analyzing developments in your coaching. Whether or not that is weekly, month-to-month, or inside a coaching block. Following and analyzing your TSS scores might help get a glimpse into the fatigue ranges your physique goes to expertise. With the ability to acknowledge when your fatigue ranges are accumulating and staying at a sustained excessive degree for weeks at a time might help you keep away from overtraining.
When you proceed to coach with elevated fatigue for lengthy intervals of time, your physique might be begging for relaxation. That is why it could actually appear straightforward to carry out a tough interval exercise through the first week again post-recovery, versus performing the identical session on the finish of a three-week coaching break – collected fatigue has set in.
When you’ll be able to monitor and acknowledge these patterns, you’ll be able to then acknowledge when it’s time to take your foot off the fuel pedal and take some relaxation.
Whereas metrics can oftentimes be complicated and make us stress over “hitting the proper quantity,” it is very important keep in mind that there are professionals and cons to at all times counting on metrics. TSS is a superb software to get a gauge of how laborious or straightforward an effort ought to be, however it isn’t concrete or set in stone that that is in reality, how your physique perceives it. Having the data of understanding metrics like TSS might help us as athletes make better-informed choices relating to our coaching than counting on the information alone. TSS might help us monitor developments that in the end assist us study when our physique wants relaxation greater than the rest. Pushing previous our physique’s limits is an effective option to acquire health, however an excessive amount of for too lengthy is after we get ourselves into bother.
References:
- https://assist.trainingpeaks.com/hc/en-us/articles/204071744-TSS-Coaching-Stress-Rating-