I’m wondering if anyone else has experienced something similar to my test results. About 3 months ago I did the standard 8-minute FTP test through trainerroad and ended up with 254W FTP. I’ve done a lot of outdoor cycling since then and feel like my fitness has improved a ton. I do better on climbs, I’m at the front of my group rides, and set several PR’s on big climbs on Strava. Then last night I decided to start back on TrainerRoad and did the 20-minute FTP test (rather than the 8min test) I gave it my all, but ended up with 252W FTP.
My questions are:
Is it typical that people score lower on a 20-minute FTP test than an 8-minute FTP test?
Am I just dillusional about gaining “unquantifiable†fitness in the last 3 months with my outdoor riding?
The good news is that I’m about 6 lbs lighter than before, so that’s something.
I don’t want this thread to get into “What does FTP mean†or “You should be able to hold FTP for exactly 60 minutes†since that’s not what this thread is about. I’m just looking for a baseline that I can test later to see if I’ve improved.
What’re your thoughts on 8-min vs. 20-min test results?
To state the obvious, the two tests are different. The 8 minute test emphasizes shorter power generation and the 20 minute emphasizes holding that power more. Pick one that is closer to your goals, probably the 20min one, and stick to it to have more meaningful data.
The 6lb weight loss is probably at least one reason why you are going up climbs better, it is possible that you haven’t improved your power at all, but you have improved the other side of the w/kg equation.
I can’t say from experience about the 20 min vs. 8 min test, but I would say they’re fundamentally different in the sense that depending on your muscle composition, you could be better at one than the other.
But more likely is just that you lost weight and with that, some power. Weight loss is what you might consider “unquantifiable fitness,” especially on a trainer. However, your overall road speed should increase (and in the end that’s what we’re all looking for) due to the weight loss so that I would consider that a win. Also if you’re still losing weight (ie. not putting in enough calories), then you’re likely not at your absolute limit and if you were before, than that would cause some differences as well.
I would just consider the 20 min test your baseline and try to replicate conditions as well as possible for your next test in the future (which should be 20 min as well).
Another possible reason could be the change from outdoor riding to coming back inside on the trainer. I have experienced an increase in my outdoor FTP over the course of the summer, but then saw an immediate drop once back on the trainer. The high inertia of the trainer can play a role as well as the lack of cooling that occurs inside. I will say that after I have spent time back inside on the trainer my FTP numbers get much closer to what I can do outside. I would suggest using the same technique/procedure whenever you test FTP and if your training is effective you should see improvement.
Plus, a single test does not a dataset make. You have one 8-min test and one 20-min test. To measure progress you need to do the same test, under the same conditions (environmental AND physiological), repeatedly. It doesn’t really matter much which one, except to say that one is more relevant (predictive) to your race distance than the other.
But, I find it pretty easy to “fake it” through an 8-min effort. Much less so when doubling (15-30 minutes) that duration or more.
I don’t “test” per-se, but I do FTP intervals (2-3x20m-30m) every Tuesday on the same road near my house. I do have to account for changing conditions as the seasons progress. But, week over week they are pretty stable. So, I plot avg power over time along with bike CTL and ATL, HR, and outdoor temperature.
Everyone is different. I can make a pretty good 8 minute and 20 minute number, there is no way my ftp is 95% of my 20 minute number though. The best way to test is by doing a 40k TT.
Everyone is different. I can make a pretty good 8 minute and 20 minute number, there is no way my ftp is 95% of my 20 minute number though. The best way to test is by doing a 40k TT.
Everyone is different. I can make a pretty good 8 minute and 20 minute number, there is no way my ftp is 95% of my 20 minute number though. The best way to test is by doing a 40k TT.
Just curious…about the bolded. Can you expound?
This is the exact point in the thread where the topic turns toward “What does FTP really mean?” This happens in all FTP-related threads. Lets not go there
Thanks everyone for the responses so far. Super helpful!
Everyone is different. I can make a pretty good 8 minute and 20 minute number, there is no way my ftp is 95% of my 20 minute number though. The best way to test is by doing a 40k TT.
I’m in this camp too - My phenotype is very much that of a pursuiter.
I use 92.5% of my 20min max to get a better bead on my 1hr power.
I did the 8min test exactly once on TrainerRoad and then never again, since it gave me an FTP estimate so high that it was just blowing my legs off in the regular sessions afterwards. It just doesn’t suit me.
It could be that the OP’s physiology is fairly close to mine, and that they’re just relatively stronger in the 8 minute test.
I definitely stand by the last sentence in ridenfish’s comment. A 40k TT is the only way that you can “know”.
Everyone is different. I can make a pretty good 8 minute and 20 minute number, there is no way my ftp is 95% of my 20 minute number though. The best way to test is by doing a 40k TT.
Just curious…about the bolded. Can you expound?
This is the exact point in the thread where the topic turns toward “What does FTP really mean?” This happens in all FTP-related threads. Lets not go there
Thanks everyone for the responses so far. Super helpful!
THE reason I asked in the first place is…isn’t that the formula (95%) for a 20 min. test?
Everyone is different. I can make a pretty good 8 minute and 20 minute number, there is no way my ftp is 95% of my 20 minute number though. The best way to test is by doing a 40k TT.
Just curious…about the bolded. Can you expound?
This is the exact point in the thread where the topic turns toward “What does FTP really mean?” This happens in all FTP-related threads. Lets not go there
Thanks everyone for the responses so far. Super helpful!
THE reason I asked in the first place is…isn’t that the formula (95%) for a 20 min. test?
I certainly didn’t mean to derail your thread.
Doh, looks like we’re going to the forbidden zone. Just like all political arguments end with someone being compared to Hitler, every FTP thread ends up in a discussion of what FTP really means, or if someone can actually hold calculated FTP for 60 minutes. It was bound to happen! haha
The 20-minute FTP test has you go all out for 20 minutes, then takes 95% of the average power and says that’s your ESTIMATED FTP, or what it thinks you can hold for 60 minutes. The poster above is saying he doesn’t think that formula is accurate for himself since he doesn’t think he can hold 95% of his “20 min average” for 60 minutes.
Based on the comments above, it sounds possible that I just have strong 8-minute power compared to 20-minute power, so even if I’m more powerful than before, it may not be clear since I didn’t do the same test both times.
Everyone is different. I can make a pretty good 8 minute and 20 minute number, there is no way my ftp is 95% of my 20 minute number though. The best way to test is by doing a 40k TT.
Just curious…about the bolded. Can you expound?
This is the exact point in the thread where the topic turns toward “What does FTP really mean?” This happens in all FTP-related threads. Lets not go there
Thanks everyone for the responses so far. Super helpful!
THE reason I asked in the first place is…isn’t that the formula (95%) for a 20 min. test?
I certainly didn’t mean to derail your thread.
I’m mostly messing around about the derailing the thread, so hopefully it doesn’t come off as harsh.
If FTP topics keep going in that direction it probably means more discussion is needed for a consensus, which is what these forums are for.
Everyone is different. I can make a pretty good 8 minute and 20 minute number, there is no way my ftp is 95% of my 20 minute number though. The best way to test is by doing a 40k TT.
Just curious…about the bolded. Can you expound?
This is the exact point in the thread where the topic turns toward “What does FTP really mean?” This happens in all FTP-related threads. Lets not go there
Thanks everyone for the responses so far. Super helpful!
THE reason I asked in the first place is…isn’t that the formula (95%) for a 20 min. test?
I certainly didn’t mean to derail your thread.
**The poster above is saying he doesn’t think that formula is accurate for himself since he doesn’t think he can hold 95% of his “20 min average” for 60 minutes. **
!
First test I was 190 lbs, now I’m 184.
My power to weight ratio isn’t impressive for a cyclist, I know.
I wrestled in high school and college and focused a LOT on weight lifting. I don’t have a typical cyclists body but it’s changing quickly.
Now I’ll derail my own thread: I got a Dexa Scan done last week and found out I have 13% body fat, and that my right leg is 2 lbs HEAVIER than my left. Jeez!
Just a thought, some of your gains in speed may be attributable to improvements in core strength and your ability to hold a quality position on the bike as you develop through the season.
You had a 2.3% increase in w/kg (2.95 → 3.02). Plus like mentioned you may just be better at an 8 min test than a 20 min test. Physiology and psychology bruh.
What is your goal? What do you want to be good at? 8 min efforts? 20 min efforts? HIM efforts? I would judge your improvement based on what you want to be good at. Otherwise the 8 & 20 min tests are just to make sure your power targets for your interval training are optimized. For this reason, I am starting to lean more towards the 8 min test to make sure my VO2 intervals are optimized. I figure out my target HIM race effort out on the road during simulations.
Everyone is different. I can make a pretty good 8 minute and 20 minute number, there is no way my ftp is 95% of my 20 minute number though. The best way to test is by doing a 40k TT.
Just curious…about the bolded. Can you expound?
This is the exact point in the thread where the topic turns toward “What does FTP really mean?” This happens in all FTP-related threads. Lets not go there
Thanks everyone for the responses so far. Super helpful!
It’s really not derailing your thread, irreverent of how you measure & quantify FTP the extrapolation of power at different duration is always an estimate.
Some riders can go well above FTP for 8 minutes, some can hold a significant percentage of their FTP for over an hour.
When you change the protocol from 8 to 20 minutes you’re not just getting a read on your FTP, but also what your power curve looks like.
Fundamentally you can use your FTP to guess what power you can hold for 8/20/60/90/… minutes, but you won’t know if you can till you do.
