Me too but look right bellow on “Prior daily Load”. It shows zero but I do have a load of 25 from yesterday.
And, If I change to “Next activity Today” “Prior daily Load” we get my today’s load of 109 and no prescription for the next activity.
I’m trying to understand “Next Activity Tomorrow” vs “Next Activity Today”.
Also, what is this recommendation based on?
William should answer the first part of your question, as I do see a Prior daily load if I have done something on the same day. The lookup is in row 5, when I believe it should be row 6.
The recommendation is based on the load needed to get to green. Load is dependent on the intensity and duration, which is what the table below the recommendation. The higher the intensity, the shorter the duration.
(1) The load from the last workout, providing it’s the same day
(2) The next activity load is the shortfall from keeping the form in green
(3) The various workout durations will give different loads.
Thank you
Thanks, I’ll add the other one later
Sorry for slow response, haven’t had a chance to reply until now.
@Gerald pretty much has it figured out. It’s just trying to hit a target Form% in the short term (next activity). That could have been achieved with ramp rate but I chose to target a Form value instead - over longer periods the two do relate to one another of course. There is an attempt to avoid training monotony rather than periodisation by looking at the intensity of recent activities to give a recommended intensity. I could have added some explainers to the sheet but I didn’t spend too much time on this to be honest. By all means modify your version to function more how you would like if you think some of the choices I made were strange 
As for the “prior daily load”, I see the confusion, but that is not trying to give yesterday’s load, it is trying to give load already accrued today, e.g. if you do a double day and want to figure out after the first activity how hard you should go in the second activity to achieve your set form target. So whenever you set to “Next Activity Tomorrow” it will be zero, and should only be non-zero if you set to “Next Activity Today” and have already done an activity today. Hope that makes sense? Happy to update the template with a better descriptor / title of the cell though if you can think of one!
This seemed an appropriate place to share that I have made some updates to the above discussed Google Sheets doc that leverages the Intervals.icu API.
This is the Direct Link to take a copy from if you want to use it: Next Activity_icu v1.1 (shared) - Google Tabellen
And it is kept in this shared Google Drive folder, where I will put any further updates: Next Activity_icu – Google Drive
What’s new?
Below is a screenshot of how the Dashboard looks for me, with my intervals.icu data already pulled through the API.
Exactly what I needed to understand this all! 
This is really outstanding. So helpful. Thanks.
@William_Barnes
I love the next_activity tool. Super usefull for having a more dynamic training “plan” that takes ALL activity into account. I’ve found the Garmin Training Plans to be too dogmatic for my taste, and the virtual coaches and Daily Suggested Workouts to be completely unaware of activities in other sports.
I’ve encountered some unexpected behavior in version 2.8 of the Google Sheet. When I set $Next Activity:B5 to “Strong/Fresh,” the values for B8:F8, and for B9 all become vlookup errors, “Did not find value ‘-1’ in vlookup evaluation.” All other values for B5 work as expected.
As a troubleshooting measure, I created a new copy of the sheet directly from your shared document. Before adding my credentials, and thus before importing my activity history, all works as expected. Once I imported my data, the new sheet exibits the same unexpected vlookup error.
I’m happy to perform any other troubleshooting you might need, and provide any other info which may help.
Thanks again for the great tool. Luckily, I’m not feeling as fresh today as I was yesterday, so I’ll just “downgrade” my self assessment and adjust from there.
Hi @Kristopher_Dick,
I’m glad you find the tool useful and thanks for the positive feedback! Thanks also for informing me of this error that has crept in (it won’t be the last!), I’ve had a go at recreating it but haven’t managed to so far unfortunately. I’ll send you a private message to see if we can get to the bottom of it together.
I would like to start by thanking you for sharing this great tool! It is unique in its form. I was able to import everything without any issues with the current version (v3.00). However, a message in a tab in “Zones” appears saying that the Power and Pace Zones (run) are not retrievable because they are not set in the settings (Not defined in Intervals.icu). But they are set. What am I doing wrong? - Thank you in advance
Hi @APFFME, thanks for your kind words and I’m glad that you like the tool!
Sorry for this slow response to your query, I don’t recall seeing a notification for it.
There are a few things in the Zones tab which are accompanied by the statement “Not defined in Intervals.icu” or similar. This is nothing to worry about as these are parameters used in the tool to define your HR/Pace/Power models which do not have direct comparison metrics which you can manually set in intervals.icu.
You should (hopefully!) have the numerical values corresponding to your intervals.icu set zone thresholds in the Zones tab still. If you don’t have those though, or my explanation hasn’t hit the mark, I’d be happy to try and help further if you can provide some more detail.
@William_Barnes do you know whey Next Activity_icu v3.00 , dont read anymore hr and power?
With some errors like “Not defined in Intervals.icu” , even with everything is ok
@R_S1, I think I have fixed this issue which occurred due to some more data being included in some of the API calls. I was planning to include a few more updates but time has got away from me! There is now a v3.01 in the usual folder location which should now work as expected. If it doesn’t though, please let me know and I’ll try to fix it in a more timely manner…
Tnaks William looks like this is the issue! work fine now!
Did yuou take off, the “selection” of type of training “yes/no” question?
When tou gonna do another update, if possible include “Alpipe Ski/Nordic ski” and “Indoor rowing/rowing” will be awesome 
I’m coming back to this topic 3 years later and I’m still wishing that Intervals would just tell me what load range I need for today to stay within -10 to -30.
I did the math on the spreadsheet that I created way back when and somehow I got it very wrong - I thought I needed to do a load of 70 to move from -9 to -10. Load 70 moved me to -17 and now I’m too fatigued (and don’t have the room) to do a century I had planned for tomorrow.
I’m back to training for this 160 mile ride in July and it just takes A LOT for a normal, non athlete person to get there.
It would just be really helpful to have on the calendar and the fitness chart to do the math of what training load I need just for today to maintain a form of -10 to -30.
Off topic I’m also sort of curious how long you can effectively remain in Optimal Training form - seems like at some point it would have mixed results.
Hi Jason,
I feel like I’ve posted this before, but maybe not on this thread.
I’m using the usual exponential decay formulae with the normal 42 and 7 day figures, which gives me that new Load contributes 0.023528*Load to Fitness and 0.133122*Load to Fatigue and Fitness decays to 0.976472*Fitness and Fatigue decays to 0.866878*Fatigue overnight.
If you’re going to do some LOAD today, and you want to know how much to do to keep yourself at Form = -10:
Fitness(new) = Fitness(old) + LOAD*0.023528
Fatigue(new)= Fatigue(old) + LOAD*0.133122
You want Fitness(new) - Fatigue(new) = -10. So, substituting:
Fitness(old) + LOAD*0.023528 - Fatigue(old) - LOAD*0.133122 = -10
Rearranging, you get:
LOAD = (10 + Fitness(old) - Fatigue(old))/(0.133122 - 0.023528), or
LOAD = (10 + Fitness(old) - Fatigue(old))/0.109594 [Formula 1]
Similarly, for Form = -30, the formula is:
LOAD = (30 + Fitness(old) - Fatigue(old))/0.109594 [Formula 2]
You didn’t ask for this but, if you’ve finished for the day but you’re going to do some LOAD tomorrow, you need to take account of the decay overnight:
Fitness(new) = Fitness(old)*0.976472 + LOAD*0.023528
Fatigue(new) = Fatigue(old)*0.866878 + LOAD*0.133122
You want Fitness(new) - Fatigue(new) = -10. So, substituting:
Fitness(old)*0.976472 + LOAD*0.023528 - Fatigue(old)*0.866878 - LOAD*0.133122 = -10
Rearranging, you get:
LOAD = (10 + Fitness(old)*0.976472 - Fatigue(old)*0.866878)/(0.133122 - 0.023528), or
LOAD = (10 + Fitness(old)*0.976472 - Fatigue(old)*0.866878)/0.109594 [Formula 3]
Similarly, for Form of -30, the formula is:
LOAD = (30 + Fitness(old)*0.976472 - Fatigue(old)*0.866878)/0.109594 [Formula 4]
So these four formulae are what you need (apart from stopping them going negative).
So, for example, if you look at your current Fitness and Fatigue values, plug them into Formula 3 and plan an activity for tomorrow with the Load it proposes, you should see your form curve hitting -10. It might not be spot-on because intervals only displays rounded figures for Fitness and Fatigue.
You really want intervals to display these for you, and custom activity fields might let you do it, but you really have to have done an activity - you can’t display them at the Fitness level (at the moment).
Hope that helps.
Appreciate this
I want the app to do this math
the copy of load training example file which I thought was based on this no longer calcs accurate values
It’s just not possible at the moment, I believe. For now, you might have to create a little spreadsheet of your own where you plug in your current Fitness and Fatigue values (read from intervals) and get it to calculate the four Loads (Today -10, Today -30, Tomorrow -10 and Tomorrow -30).
I’m not sure what’s going on there.
