I HATE the 4DP

I don’t hate it, I just don’t do Full Frontal.

I’ve done it once, appeared that I’m a Time Trialist with a ‘sustained weakness’. I doubt this will ever change, so I’m ok with that. I’ve prepared a couple of times for FF and life got in the way of proper preparation, so I have postponed it numerous times and eventually just didn’t do them.

Like you, I don’t race. I don’t even do group rides. I don’t care about sprints or 1min efforts. MAP means something for me as the hills here are short and steep. FTP is a base number for all the workouts. Therefore, I only need to do Half Monty every once in a while. So I have decided only to do FF when I really feel like it and have two weeks to sacrifice for it (1 week prep, 1 week recovery)

In short: Find a way that works for you. If you don’t like Full Frontal, don’t do it. Life’s too short to hate.


You quit, I guess…


The reason I asked @Edaudman was to get his understanding as to what he perceives as a fail and his why thereto.

@CPT_A Quitting a 4DP is not failing, that’s just giving up. That’s not having the foresight to see that I need to draw a line in the sand of where I am physically and mentally, and anything hereafter is going to be an improvement should I follow a plan.

Having the expectation of reaching an magical number after test and being defeated therein is also not a fail, its a realization of where one is at. That is a beautiful thing knowing that a weakness is an unexplored strength and the road to uncovering it is the journey we call cycling training.

Quitting is not necessary failing, that’s why I don’t guess and rather ask.


As someone older than you are, I would say that your atrial tachycardia is the issue, not your age. I did my last FF last month.

On the other hand, if you do not feel that a FF corresponds to what you need, then do not do it. I find I need a benchmark to make my training more focused, especially because as you age recovery becomes more important.

The 4DP AC number only makes sense within the FF, because it is not a pure 1 minute effort measure, it is a measure of you ability to recover from sustained efforts. I suppose you could do n x 20s to measure that.


If you don’t like it and it’s not for you that totally OK. We all have to find what works for us.
It’s made me stronger and fitter as I’ve got older and in a way that I find entertaining and engaging. Quite literally can’t get enough :grinning:
Each to their own… I hope you find your happy training place


I think one of the ways Sir Neal has mentioned to get an accurate AC number outside of FF is to do The Trick in level mode and take your average power for the 3rd interval.

So, you could do the first two sprints in FF. Do HM. And then to The Trick. All on separate days. And that would give you a close enough approximation of your power numbers to use in your 4DP profile for your workouts.


Haaa. I set my all time 1min power record in the 3rd interval of the Trick (in level mode).
I did FF 2 days later and my AC recording was 93% of that record. (I probably had a bit of fatigue given the 2 day gap).


My stats from a hill climb late summer. The climb took me 2 mins and 32 secs. My 1 min power then according to FF was 332 watts ( 5.44wats per kilo) My average 1 minute on the climb was 384 watts ( 6.5 watts per kilo, not to mention the other stats!

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Yep, your numbers there definitely makes sense.

In Full Frontal the AC is measuring not primarily your 1 minute power, but your ability to do that 1 min effort after you recover from all those other efforts done before. Because you could easily do better 1 min power in isolation. So it’s more a measure of recovery than pure power. And then that’s how it’s used in your workouts.

So, not surprising your 1 min power from your hill climb is higher than your AC from FF.

Now, if you did that hill climb 3 or 4 times and THEN took compared your 1 min time from your 3rd or 4th effort, that would be better comparison.

So when you do Fight Club or HHNF or Cobbler and you’re asked to do an AC sprint at the end of a huge effort, the workout can simply then give you a target of 100% of your AC value knowing that you hit that power while fatigued. Rather than trying to do some percentage calculation of your all-time PR 1 min power that you may or may not be able to hit based the difference in recovery abilities of different riders.

So while it’s not an apples-to-apples comparison, it fulfills a specific purpose in your workouts based on how it’s derived in FF. And that helps make it work better for more riders. Rather than doing a % calculation which would be less accurate for more people.


Here’s a good recent post from Sir @David.McQuillen.KoS in a related thread that links to 2 episodes of the Knowledge podcast where they discuss 4DP.


I agree with @emacdoug.

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That’s why I try to do it, to give me an accurate baseline for training in the winter. But it’s not just the tachycardia, but it’s the extensive commitment to prep and pacing needed to successfully complete it. In the long term, since I don’t compete athletically, I’m probably good with just the FTP, MAP, and cHTR that the Half Monty provides. It’s just I’d like know the AC and NM abilities for those few time I need them.

I did wind up doing the Half Monty with no issues. On to my winter plan


You got it. Or you continue to plod on at levels significantly below your true abilities to arrive at levels that inaccurately represent your abilities because of the pacing required. And since your training plan is based on these results, it results in ineffective training plan.


It’s a miracle anyone managed to push themselves before HR monitors, power meters and apps existed. You can actually turn off the erg mode, and do what most amateurs do every weekend, get on the bike and one in a while prove to yourself what you can do, indoors as well! Your best NP on Thin Air is something you can safely think of as FTP, certainly well enough for tracking changes and gauging IF on other 90% level endurance workouts relative to that. If you can’t hit quite the same IF on MAP-like workouts then you correct those a little (there’s your 4DP), but you pay attention to your best on them, on days you’re going for it, and how that changes. This really isn’t rocket science.

The suff workouts are great, and with a power meter, give a great way to monitor progress and great activities to get in volume without boring technical interval workouts and testing. I found it more convenient when they used to all be pegged similarly close to 100% of something we could call FTP, but it still works. Just turn off erg mode and aim for 20 watts higher sometimes.


Completing HM gives you an excellent pacing guide for FF. But regarding the 5 and 20 minute intervals, you can do negative splits on those.

Start below your HM numbers and increase every 2 minutes, finishing each interval as hard as you can safely do.

Keep an eye on your heart rate, you should be hovering around your LTHR from HM. A bit lower at the start of each interval and finishing a bit above.

Also, even if you take it a bit easier on FF’s 5 and 20, so long as you’re reasonably close to your HM values, it will give you a fatigued 1 minute AC component. Thus, when paired with your HM results, it will provide full 4DP values.

I HATE the 4DP!! just completed FF for the 3rd time (took a year off since the last one which I hated so much!) Picked up some tips along the way…First I need a longer warmup before starting. “Igniter” at 80% did the trick. Next, some experimenting with Level Mode on “Open 15” helped with finding the best gears for the different intervals. Results were improvements across the board which was pleasing. Looking forward (?) to suffering with fresh numbers…maybe not tomorrow! :sunglasses:


I always need some extra warmup before FF. I usually do the Pre-Ride Warm-Up yoga immediately prior to getting on the trainer to do FF.


Yep, the pre-ride activation yoga is a great warm up for all the high intensity sessions.

Personally i don’t feel like extra on the bike warmup is needed for FF. Usually a long warmup is required when you are a bit stiff/sore/fatigued, which should never be the case going into a FF.


I’ll often feel like I need an extended warmup after a day of sitting at a desk. If I tried to do FF then, I would almost certainly throw in some extra on-bike warmup. I’m otherwise ready for the test, but need some extra time getting muscles moving and blood flowing.


I typically do FF early in the morning. So that usually requires some spinning to wake up first. But when I do FF later in the day I don’t do any kind of warm up.

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