How to get one step ahead in 2017

As many of you will be using Xert for the first time over the off-season, I thought I’d give some advice, not based on any coaching methodologies but on what the numbers have told us, after analyzing thousands of activities.

In Xert, you have 3 systems that are affected by training: low, high and peak. Low associates with your Threshold Power (FTP, essentially), High associates with your High Intensity Energy (HIE, similar to W’ or FRC) and Peak associates with your highest power outputs (PP and similar to Pmax – your highest power possible). As you can imagine, each of these have some bearing on your ability to generate power and will have a varying influence depending on the type of the athlete (Athlete Type) you are training for.

(There is another number that will play a big role in your training: Lower Threshold Power or LTP. Keep reading…)

What the numbers have shown is that it takes longer to develop your FTP than it does your HIE. It also takes longer than PP. In technical terms, the time constants for positive adaptation are longer from low inten sity strain than they are from high intensity strain and peak intensity. Conversely, the recovery needed for low intensity strain has less demands, in comparison to high and peak. High Intensity Strain accumulates quicker, dissipates quicker and recovery demand is greater. Recovery demands from low intensity strain are modest in comparison.

What does this mean? It means that to improve your FTP, you need volume and it’s okay to load up without too much concern for recovery demands. The one caveat is to pay close attention to your LTP. Even if you work just below your FTP, you’ll be limited in your ability to add strain if you train near FTP. This is because it’s more difficult to add volume as intensities get closer to FTP. You’ll burn off your endurance energy and you’ll have to stop. In fact, FTP will decline as your endurance energy gets consumed, making it even harder to sustain power. Whereas if you can train near, and preferably just below your LTP, you can accumulate a lot of strain without affecting endurance energy supplies. This reduces the recovery demands. In fact, even when you need recover from high intensity training, you can still load up on low intensity strain. Just don’t go too hard and stay well below your LTP to avoid putting demands on your endurance energy system. (Endurance Energy is a concept we’ll be introducing into Xert in 2017 and is associated with carb/fat utilization.)

So if you’re training to be your best starting in April, click over to My Fitness and click on the Advanced tab to see what your Lower Threshold Power is. Spending a great deal of your training time at or just below this value is optimal. If your highest Training Load during the season is 100, accumulating 50 or more XSS of low intensity strain as a daily average is something to be striving for at a minimum. (Soon we’ll have workouts that use LTP as a target during intervals so that you don’t need to monitor it yourself). If you can afford the time to have this number get closer to 60 or 70, even better. Just recognize that this takes time. It’s also ok to add some intensity here but if it affects your ability to add volume, don’t do it. Wait.

In mid winter, you should commence your higher intensity training. By now, you’ll have accumulated a solid base. It’ll be hard at first to do any effort above TP, but that’s ok. We know we’re going to get real fast so it’ll be worth it. This is when you start to add in high-intensity workouts and you start to add in more and more intensity and have the Focus of your workouts start to move towards your target Athlete Type. You should be aiming to do high intensity workouts that are at least 1.5x the current training load in XSS and do them 2 to 3 times per week. So for example, if your training load is 50 at that time, your XSS for the high intensity workouts should be at least 75 XSS. Try and maintain low intensity volume as high as you can to keep your low intensity training load high. Note that you should push to the limit at least once a week to keep Xert up-to-date with your current fitness signature.

The 80:20 low:high polarization rule will work well here since the 80 keeps FTP up and the 20 adds high strain, lifting your HIE and also lifting your FTP which gets added strain from having to work when MPA drops during your workouts. The goal is to continue to add training loads, lowering Focus towards the duration you are aiming for. Depending on where your training loads are at and how much your body is able to absorb in one workout, will dictate how much strain you can add. The important thing is to be able to add as much strain as you can during individual workouts. If you’re tired and aren’t able to complete the workouts, your XSS numbers will suffer and thus training loads will suffer. So train hard and rest just as hard. The rest will allow you to train harder the next time.

One thing we’re adding to our workouts is the ability to be specific on the amount of XSS that you’ll accumulate during the workout. We recognize that it is possible to over-train. We have yet to identify the patterns that make up over-training but one may surmise that if the accumulated training loads are low, daily strain loads are high and not enough time is given to recover, one can get into the pattern where you’re always tired and training when you’re tired on a consistent basis. We think there is a pattern here that we will find. For the moment, just be wary that you can’t simply pile on the training load. There must be a gradual increase commensurate with the adaptations that are being generated during recovery which will enable you to handle the increased loads.

In the new year, take advantage of our new smart intervals to be very precise on the training loads you want to add to your training program. One of the cool new workout types you’ll see are called “Hardness Tests”. I’ve attached a sample of the Level 7 test. Use these tests to gauge how much strain you can handle in 1 hour. The greater the strain, the harder you are. … and again, don’t forget to recover just as hard after you do them!!

Good luck in 2017.
Xert Smart Interval Workout

Thanks Rohan for the correction.

Armando, thanks for your post, very well written and extremely useful.
After reading it, and especially where you discuss the differences between recovery for above LT and below LT efforts and how fast High LT and Low LT, peak and HIE can be built up, the question that comes to mind is how to reflect this in the XPMC settings for Training and Recovery load time constants.
By default, these are all set to 42 - 7 … Given what you wrote, isn’t there a case to modify these appropriately to your suggestions on how fast you can improve and recover your Peak Power vs HIE vs TP ? Shouldn’t the default values created in Xert reflect your suggestions?


Rodrigo. Thank you.

You are correct. The time constants (tau1 and tau2) are not seen to be 42 and 7. However, the k1 and k2 values are also different as well and are not seen to be 1 and 1, as per defaults in our XPMC and other PMCs. This is at its core what we’ll see change in phase II. At the moment, you can change the time constants but not the k1/k2 values. If you allow k1/k2 to change, the XPMC won’t necessarily be properly reflected for this reason. You’ll then need to account for P0’s. Hence … we need more features… :slight_smile:

For example, for the low intensity IR model, preliminary population-wide results indicate a low intensity tau1 (~70 days) is over three times as long as the high intensity tau1 (<22 days). For low intensity, k2 is smaller than k1 whereas for high intensity, they are closer. You can experiment with these numbers but recognize that the k1/k2 values are currently 1 for all three models and thus will need to be accounted for in your interpretation.

Note that if you do change the time constants, they will get reflected in the proj ected values. As mentioned before, the projected values only take into account Training Loads (i.e. the tau1 and k1s of each of the models) and not Recovery Loads. Thus they only give a general idea of where values could end up. Much will depend on the specific day and the workouts leading up to it.

Reading and trying to understand the '17 approach I like to ask you the following. For this time of the year I understand the best practice is building fitness with volume and intensity just below LTP. Do you advise intervals with ‘rest weeks’ between ‘load weeks’ tlll mid winter?

Thanks for this post, I think this should be a blog post though - you’ll get more visibility! :slight_smile:

Hans, the IR response model isn’t sophisticated enough to see how rest weeks and load weeks interact over the long term. In fact, it doesn’t see over-training. More load = higher fitness. My comment about over-training was from knowledge that there are physical limits on how much training load one can absorb.

I think to answer the question on whether rest weeks are needed either to improve fitness or to avoid over-training is something we have not had an opportunity to look for in the data. That day will come, particularly as we move to a broader machine learning approach in Phase III.

Armando, TYVM! Such learning machine is good news because I understand that with someone aging there has to be a change f.i. 1-3 to 1-2… for better growth and Health care

For you Ollie…

Great stuff Armando! And based on real data too. I will start following your suggested plan :slight_smile:

Looking forward to the XSS prediction for workouts and the adaptive workouts. Sounds like we shortly have a powerful training system.

Thanks for an interesting article and for advancing the Xert system! I have a question regarding how the advice on off-season training should be interpreted. Let’s say my peak training load of this year was 50. That means that I should - in the early off season - aim to add 50 %, or up to 70 % of low strain of this value. Am I right to interpret this as 25 - 35 kJ as my daily average low strain?

And later in the off-season I would like to go with the 80-20 system (roughly). Should I interpret this as 80 % being low strain effort and 20 % being high strain + peak strain? When looking back at my data it seems that I often reach some 90 % low strain in my training as my daily average, and roughly 8 % is high strain and then 2 % peak strain. This number seems a bit high compared to other software (that uses other measures of course) where I’m usually around 70-75 % of “low intensive” work out.

Michael, much depends on how much time you have available to train. Note that you should either stick with Training Load (which uses XSS) or use strain data from your strain Progression Chart to determine your data estimates. I’d stick with the XPMC for now since 75 marks the boundary from Trained to Competitive and is a good target to work towards.

So if your highest was 50, building your low intensity training load starting at 25 and moving it upwards is certainly the goal. If you can allocate the time for long rides, now is the best time for them. These will make hitting your daily average goal much easier.

80-85% low strain and 15-20% high+peak will put most people roughly at the 4-5 minute Focus, which is a pretty typical racing Focus value. If this is too aggressive, you can look to allocate at 90:10 (closer to 8-10 minute Focus). Of course, you can periodize and reduce Focus as you move closer to your target event date.

We are working to improve the tooling and features to help you to manage this more precisely. At the moment, track your progress after your workouts and use the Workout Designer to select workouts that fit the Focus and XSS levels that will help you achieve your targets.

Ok, thanks. I guess I’m beginning to get how XSS & training load relates.

I did my last session Monday, but form has still decreased even though I’ve (so far) rested two days. Why does my form decline during rest days?

And finally, I want to increase my training load. Maybe aim for 75 or so. I don’t have any competitions in sight before April. Should I worry about my form being “red” when I increase my training load?

Ollie. Thanks for sharing the link to the blog post on Reddit. It generated quite a few new registrations.

Forgive me if this is covered elsewhere but can I ask how the different energy systems are defined? And if I wanted to focus on one or the other how might I go about that. Lets say, for example, that I think my HIE is low (comparatively). Your post suggests that this is associated with the “High” energy system. How would I focus on this in training?

How is the lower threshold calculated? Mine seems to be gradually rising over time sometimes even when the other metrics are degrading. Is it just a function of XSS or is it somehow measured in each session?

Brian, raising HIE is based on accumulating high intensity strain, at least according to the data we’ve analyzed. You’ll see the quantity of high intensity strain in the Workout Designer. For activities, it’s a little less apparent. Those with the greatest high-intensity strain scores are those that combine a mid-to-low Focus Duration (1-5 minute duration) and a Pure or Mixed Specificity Rating.

Do note that raising your HIE is synonymous with raising your 3 or 4 minute power. So if you simply monitor your Focus and keep it at a lower duration, you’re essentially going to improve your HIE, since that what these lower focus durations imply.

Arto, lower threshold is derived from your other signature parameters. We’ve determined a pattern where Threshold Power and HIE decline as your activity progresses. Mathematically, LTP is higher with lower HIE values and this relationship where HIE declines where LTP increases is what you are witnessing.

Thanks, it makes sense now in the progression chart. The downside is that I though I was getting more fit but it’s just that I haven’t done much HI lately. My assumption is that if I get my TP to raise with HIE then the LTP would not drop when start to go more intense. Makes sense but it will be very painful :slight_smile: I must say compared to some other models the LTP is quite high number. I mean some other methods would recommend upper limit for low intensity for me to be ~20W less. I personally prefer to train low intensity with this higher limit though. Any thoughts on the comparison of your recommendation to others concerning the intensity of the low intensity? Or is the LTP in the easy region for most (date I say Z2)?

Our modeling suggests that what you’re saying is true. If you raise your TP with HIE, your LTP should remain fairly static. If you focus on TP and below, your HIE drops and LTP rises. If you start working on high intensity only, LTP drops and HIE rises. For TP, it will depend on the overall mix. It is in fact possible to raise TP but lower LTP. Recognizing this is actually very important for longer distance athletes like triathletes who may raise TP with higher intensity only to find their times may suffer in the end.

As it is described in our Paradigm Shift blog, if high intensity zones are based on TP alone, you may run into situations where there isn’t equivalency between athletes and workouts. Likewise, if lower zones only look at TP, they too may not be reflective of the greater fitness picture. I find it very interesting that our data shows that all your fitness signature variables are tied to one another in some fashion. You really can’t just consider one in isolation.