I started on TR last summer and have made steady FTP gains. I have heard multiple references to “all day pace” on the podcast, but I am unsure which zone that correlates with?
Is there a zone or Intensity Factor that I should be able to plan on using for 110 miles? My FTP won’t allow me to be at the pointy end, but I still want to go as fast as my abilities allow.
Thanks for your patience with the new guy question 
It’s easiest to express as perceived exertion:
First hour; chat to people.
Middle part of the race; settle down to work but enjoy the view.
Last third; dig deeper and deeper until you inhabit a surreal world of effort and nothing else.
For me, an intensity factor of around 0.8 is something I’ve done for 100 miles, but I think for a lot of people you’d look at something between 0.65-0.75 as something sustainable for a long time. I’m not personally aware of anyone having an IF of 0.85 for a century, but that doesn’t mean they aren’t out there, so I’d love to hear from those folks!
Yeah looking back at my centuries, .65 = social, .7-.75=properly hard, .79 highest ever
I think this is good guidance.
Since this is a new length of ride, I would recommend starting at the low end of the range, as it is easier to pick up the pace for the 2nd half than it is to finish after you realize you went out too hard.
Keep in mind that IF is based off of Normalized Power.
I prefer to pace with Average Power and will also hit the lap button after pit stops and descents to reset my lap power.
I’ve hit 0.87 for a rolling century. The actual effort during the ride was tough but I was fuelled well and only the final 30-40 minutes felt hard.
All that said, the following day I was in a hole. Couldn’t get warm and I had zero appetite.
As you say @hubcyclist, this type of effort is well within some peoples ability. I’ve not achieved it since and I’m not sure that I want to.
For me, a solid century effort is 0.80. Ideally, I’d like to keep it around 0.75.
For me its also about keeping my matches, keeping it a steady pace. I’ve went well for a good distance with an IF of 0.8-0.85 but I’ve also hit the proverbial wall at IF of 0.8. If I keep it to IF of around 0.7 or less I can go all day long. If Im wanting to complete a ride at a good speed I tend to keep in the Tempo zone.
I am so glad this question was asked as I am also a newbie hoping to do 100 miles in August. Being new I also had to go look up again what IF means. It was defined as “an all-out effort for an hour”… So is that FTP, or higher or lower than FTP? I am almost completely helpless with numbers, so apologies if this is obvious, but are the decimals referred to above (.75 -.80) a percentage of FTP? But if IF is an all-out effort, I don’t see myself being able to do 75 or 80% of that for 100 miles…? As @Jonmc7583 asks, is there a zone that correlates with that? And thanks again for asking!
IF of 1 is riding at a normalized power == FTP.
IF of .75 == riding at 75% of FTP (mostly accurate if you are keeping a study state, as IF is based on normalized, rather than average power.)
TR puts endurance zone at 55-75%
Tempo 76-87%
.75 might be a bit high since you are new, but .65-.70 is very likely a pace your could hold all day.
Nutrition, and bike fit/comfort also play into all-day efforts as well, but I think .70-ish is a good target.
Thank you @toyman 
! This is an answer I can understand.
Lots of solid responses here. I am happy I was at least on the right track.
I do still have a hard time comprehending the difference between normalized power and average power. But it whoever said they pace more off average than IF, makes sense to me, at least for someone trying to follow a plan for a long ride for the first time.
looking at 65-70% of FTP sure looks like a sustainable number. Maybe will start closer to 65 and then up it if I still feel good halfway or later.
IF is just a measure of your output compared to your FTP. FTP is many times defined as the all-out power you can put out for an hour (this is a slightly simplified definition but close enough). Then IF is your Normalized Power(NP) for a ride divided by your FTP. So if my FTP is 200W and I have an NP of 180W for a ride, then my IF for that ride is 180/200 = 0.9.
It should also be pointed out that an IF of 0.75 for an hour won’t feel 75% as effortful as an IF of 1.0 for an hour, it will just be 75% of the power. For example, assuming I could do my FTP for an hour (IF of 1.0) I can probably do 0.75 for around 5 hours and it will only start to feel hard in the last hour or so. A 10% drop in power might double the amount of time you can go at that power.
IF uses an formula where harder efforts are weighted more then easier efforts. Especially if your doing a hilly ride, average power might not be accurate in terms of effort.
If you are riding this event, I would go for something around een IF of 0.65. Especially if it’s mostly flat that should be a pace you should be able to do for the event.
If you’re racing it, you should aim a bit higher if you want any shot of a good result.
Maybe some pictures will help… The lower dash line is my FTP. The upper dash line is my 5-min vo2max power.
Example 1: 100 mile ride at 80% Intensity Factor:
Power summary:
See the big difference between average and normalized power? You can also see it in the power graph.
Example 2: Steady 2 hour effort at 79% Intensity Factor:
Power summary:
See how on a steady effort the average and normalized power is almost the same? And you can visually see it too.
| Ride | Intensity Factor | Average Power | Normalized Power | Comment |
|---|---|---|---|---|
| Example 1 | 80% | 185W | 219W | big gap between avg & normalized |
| Example 1 | 79% | 175W | 179W | avg & normalized almost the same |
Here’s my last century, 177Km, from 9th of April. It was a 12-man TT format, but we only had 8 starters and lost 1 rider after 3Km.
Do those pictures help?
Holding steady power means average and normalized power are almost the same. Looks like a shaky power line on a timeline graph, but you can clearly see a line.
Highly variable power timeline graph looks like a 2 year old scribbling on paper, and normalized power will be (much) higher than average power.
Normalized power gives you “credit” for all the hard efforts. Because those hard efforts over average power require a lot more heart beats/breathing, and take a toll on your legs.
I usually pace these efforts on heart rate, knowing that shooting for an average in 138-144bpm range will usually net me an IF in the 75-85% range. But I only know that after doing my first 3 centuries back in 2016, and looking back at all my long rides.
I think a key thing for newbies on long rides is to keep a lid on your power on hills, especially early on. I’ve done sportives before where early on everyone is trying to prove how heroic they are on the first hills and it’s easy to get sucked in. 80 miles later you will see a lot of people who are suffering a bit and probably wished they hadn’t burned all those matches…
This is even an issue with more experienced riders. I can’t tell you how many ‘casual centuries’ I’ve done with smallish groups of friends and everyone is doing 450W up every hill at the beginning and then at the end they look terrible and are limping home, barely able to hold the wheel.
I do a lot of long rides and am by no means fast, so I figure I’d share my 200K stats from the past two years since they are probably closer to newbie pacing numbers. (A fast rider does a century in sub 5 hours while us turtles take 7-8 hours. Pacing is very different for those two durations!)
The rides at the top of this list with an intensity of 0.76-0.78 were me KILLING myself while in peak riding form. The rides at the bottom of the list (IF of 0.62-0.66) were chill rides with lots of talking and taking it easy on the hills. The “work>FTP” in the far right column is a good indicator of how much self-flagellation was occurring. I live in hilly terrain, so a certain amount of work>FTP is required to finish a ride.
My recommendation for a newbie doing their first 110 mile ride: Try to keep your steady power at 60% (aka all day pace). The hills will require higher power, but try to keep it limited to 70-90% depending on their length and recover on the backsides. Save efforts above your FTP for your second long ride.
