Chapter 05Field Notes
The science behind your riding, one principle at a time.
Every ride is more than hard or easy.
You finish a ride with a feeling about what it was. Hard. Easy. Productive. Maybe exactly what you needed. But feeling isn't fact. Training Impact tells you what you actually hit and how hard you hit it. So you know, not just by feel.
01 · What two dimensions do for you
"Was that a good ride?" Finally has an answer you can count on.
Every rider knows the feeling after a ride: tired, satisfied, not certain what it did. Chapter 03 outlined the six engines. Chapter 04 explained the dose. Together: what was built, and what it cost. That's Training Impact.
Recovery, Endurance, Tempo, Threshold, VO2max, Race, or Mixed.
Primer, Maintain, Build, Overload, Deep Load, Event Load.
Sunday · 3h 29m · 195 TSS
Diva Loop + lil Extra
Type
Endurance
Load
Overload
Load 4 / 62.1× your fitness
Tuesday · 1h 10m · 88 TSS
Trainer · 5×4 min
Type
VO2max
Load
Build
Load 3 / 61.4× your fitness
Saturday · 2h 05m · 178 TSS
Club crit
Type
Race
Load
Overload
Load 4 / 62.3× your fitness
Three rides. Three engines. Two landed at Overload, one at Build. A week you can read without opening a single power file.
02 · Bouts, not averages
The average of a ride hides the ride.
Diva Loop averaged an Intensity Factor of 0.75. Easy day, on paper. But inside it were fourteen separate efforts above threshold, and when you average those in with the rolling between them, they vanish. To judge a ride honestly you have to find the efforts and measure them one by one. That is Work Intensity Factor, or Work IF.
1.06
Work IF · the efforts only
Intensity Factor of the fourteen efforts alone, with the rolling between them cut out.
0.75
Overall IF · whole ride
Intensity Factor of every minute, efforts and rolling averaged together.
Overall says easy. The efforts say above FTP. Both are true, and only Work IF tells you what the ride did to your legs.
Bars show % of ride in each zone; the solid fill is the qualifying dose, the minutes that drove the classification.
One continuous effort held in a zone, long enough to matter. FORM counts them, times them, and reads the ride from them. Diva Loop: 4 work intervals, 14 sprint bouts, 5.1 minutes of real Z4+ dose. That's the ride. The average was the scenery.
This is also why Anaerobic and Sprint aren't types of ride. They're bouts inside a ride. A Race has sprints. An Endurance ride can have anaerobic digs. The Type says what the ride was for; the bouts say what happened inside it.
03 · The Classifier
Two axes meet. One verdict.
Every ride is classified automatically from its bouts, zones and intensity: one Training Impact verdict, and how confident FORM is about the verdict.
Training Impact
Diva Loop + lil Extra
Type
Endurance
Load
Overload
Load 4 / 62.1× your current fitness
01Why this classification
Aerobic base work, 66% easy at IF 0.75. Mitochondrial and fat oxidation gains at low recovery cost, the foundation the plan is built on.
Tap any ride in the log and this card opens: the verdict, why, and how sure. A ride that could be two things reads low, and FORM says so.
04 · Two names that confuse people
Mixed isn't a shrug. Race isn't a zone.
Mixed
Several engines, none dominant.
Tempo climbs, a threshold pull, a sprint for the sign. Several engines got a real dose and none won. Mixed is a description, not a mistake. Group rides often are.
Race
Named for what it was.
A race is a hundred bouts stitched together with coasting. Overall IF says one thing. Work IF says brutal. Race is its own type, sized on the load ladder like everything else.
Mixed · Build · Saturday
"Group ride. Tempo on the climbs, one long pull at threshold, a sprint. Mixed at Build. Good day. Don't apologise for it."
Race · Deep Load · Sunday
"Overall IF 0.91. Work IF 1.18. The average called it a hard tempo ride. The bouts called it what it was. 3.4× your Fitness. Monday is off."
05 · The block
Pick a window. Read it as one thing.
Rides don't work alone. Fitness is built in blocks, so FORM reads them in blocks: the past 14, 30, 60 or 90 days, whichever you pick. Everything on this page is computed over that window.
Load Density · past 30 days
Chapter 04 sized one ride against your Fitness. Load Density does it for the whole block: every TSS you deployed, over every day of Fitness you had. Over 100% means you spent more than your capacity.
06 · The pattern
One ride is a fact. Thirty is a pattern.
Count the rides into a grid, engines down the side and load across, and the block stops being a list. It becomes a shape, and the shape is what a coach reads.
Endur9422·· Tempo······ Thresh······ VO2max·3···· Mixed··1211 Race···21·
What the coach sees · 29 rides, 30 days
"Your base is built. Seventeen aerobic rides, four of them a real dose. Your top end is racing, not training. And the middle of the ladder is empty."
- Two whole rows are blank. No Tempo, no Threshold, for a month. Whatever FTP you have is coasting on last season.
- VO2max only at Maintain. Three sessions, none big enough to move the engine. Exposure, not development.
- Races are doing the hard work. Five Race and Mixed rides at Overload or above. That's where the intensity lives, and races are a bad place to train.
07 · The mix
Where the hours went. Two ways to count them.
The grid counts rides. Hours tell a different story, and FORM splits them along both axes.
Training Stimulus Mix
Which engines got the hours
Your body doesn't care where the stimulus came from, so neither does this. Trainer intervals and a 14% climb land in the same bar.
Relative Load Mix
How big the doses were
The same hours, sorted by rung. This is where a block that looked easy turns out to be 27% Overload or harder.
None of this needed a power file. It needed the rides, named and counted. Chapter 07 uses the same block to compare what you planned with what you did.
08 · The fine print
Five things that are always true about Training Impact.
The two dimensions never touch
What the ride was and how big it was are separate facts. Any Type can carry any Load.
Bouts beat averages
The verdict comes from the efforts that qualified, not the minutes that happened to add up.
Mixed is a result, not a fallback
It means several engines got real dose and none dominated. That describes a lot of good riding.
Confidence is part of the verdict
FORM tells you how sure it is. When it's low, take it as provisional and let the debrief settle it.
It's fixed at roll-out
Judged against the Fitness you had that morning. Getting fitter later never regrades an old ride.
You've always known how a ride felt. Now you know what it did.
Chapter 03 named the engines. Chapter 04 sized the dose. This chapter put both on every ride you'll ever do, and showed you how to read a month of them. The next question is the one every athlete asks on Monday: how good will I be on Thursday?
Next chapter: Mostly easy. Sometimes fierce. Polarization, and the shape the fastest athletes converge on.
Field Notes · Chapter 05 · Every ride is more than hard or easy.← 04Next · Chapter 06 · Mostly easy. Sometimes fierce. →