The screen that scares people off
You've signed up for coaching. Your first structured workout lands in TrainingPeaks. You open it and there's a coloured chart, a wall of numbers, abbreviations everywhere, and a workout description that reads like a technical manual.
Most riders do one of two things: panic and overthink every number, or ignore the details and just ride by feel. Neither is ideal. The good news is you don't need a sports science degree to read your workout. You need to understand about five things.
The workout description: read this first
Before you look at any number, read the text your coach wrote in the workout description. This is where the session's intent lives.
A good description tells you what the session is for, what the target power or heart rate zones are, and how the intervals should feel. It might say something like: "3x12min at 88-92% FTP with 4min easy between. These should feel controlled and sustainable — not eyeballs out. If the third interval feels significantly harder than the first, you started too high."
That paragraph tells you more about how to execute the session than any metric on the summary screen. Joe Friel — the godfather of structured endurance training — always emphasised that understanding why you're doing a session matters more than nailing every watt. The why keeps you honest about execution.
The three numbers that matter
TSS (Training Stress Score)
TSS quantifies how much training load the session puts on your body. Think of it as a single number that captures both duration and intensity.
The reference point: riding at your FTP for exactly one hour scores 100 TSS. An easy 90-minute Zone 2 spin might be 55-70 TSS. A hard interval session could be 85-110 TSS. A five-hour sportive might accumulate 250-350 TSS.
You don't need to target TSS during a ride — it's calculated afterward. Its value is in tracking cumulative load across a week. Most age-group cyclists accumulate 300-550 TSS per week during a build phase. Going significantly above that without a ramp-up invites trouble.
IF (Intensity Factor)
IF tells you how intense the session was relative to your threshold. It's your Normalised Power divided by your FTP.
Quick reference:
- Recovery ride: 0.55-0.65
- Endurance ride: 0.65-0.75
- Tempo: 0.76-0.85
- Threshold work: 0.85-0.95
- Above threshold / race: 0.95-1.05+
If your coach prescribes an endurance ride and your IF comes back at 0.82, you rode it too hard. This is the number that catches people out. It doesn't matter that the ride felt fine — an endurance ride done at tempo intensity isn't an endurance ride. The training adaptation changes.
NP (Normalised Power)
Average power is a blunt instrument. If you ride 200w for 30 minutes then coast downhill for 30 minutes, your average power is 100w. But the physiological cost was far higher than a flat 100w effort.
Normalised Power accounts for this by weighting harder surges. It better reflects how the ride actually stressed your body. On flat, steady rides, NP and average power are close. On hilly or punchy rides, NP will be meaningfully higher than average.
When your workout says "target 220w NP," hold that as your guide for the effort blocks — not the average across the whole file including warm-up and cool-down.
The coloured zones chart
The graph at the top of your workout in TrainingPeaks shows intensity over time, colour-coded by training zone. Blue and green are easy. Yellow is tempo. Orange is threshold. Red is above threshold.
For structured workouts, this chart is your visual roadmap. You can see exactly when the intervals start, how long they are, and what intensity they target. During the ride, the live version of this chart shows whether you're above or below the target zone.
The most useful thing about the chart isn't tracking the intervals — it's checking the recovery valleys. If the prescription shows blue recovery between intervals and your actual data shows yellow or orange, you're not recovering between efforts. You're just riding hard continuously, which is a different session with different adaptations.
Why following the plan matters more than smashing it
This is the hardest lesson in structured training. Friel wrote about it decades ago and coaches are still having the conversation daily.
When you feel good, the temptation is to go harder than prescribed. You're fresh, the legs are turning, and 280w feels easy when the workout says 260w. So you push to 300w.
Three problems with that.
First, the workout was prescribed at that intensity for a reason. Threshold intervals at threshold develop threshold. Threshold intervals done at VO2max intensity develop something different — and create more fatigue for a different adaptation than what the plan intended.
Second, going harder today borrows from tomorrow. That extra 40w costs recovery time you were supposed to spend absorbing today's work and preparing for tomorrow's session. Now Thursday's key workout suffers because you were a hero on Tuesday.
Third, consistency over weeks matters infinitely more than any single session. A rider who hits 90% of their prescribed targets for 12 weeks will outperform someone who smashes two sessions, skips one from fatigue, smashes another, takes an unplanned rest day, and repeats that cycle.
The plan is the plan. On good days, stay in the zone. On bad days, adjust down — that's also following the plan.
What to do when you can't hit the numbers
Some days you'll open a workout calling for 4x8 minutes at 280w and your legs won't produce 260w. It happens. Fatigue, sleep, stress, nutrition, illness — dozens of variables affect daily output.
The protocol is simple: attempt the first interval at target. If you're consistently 10% or more below target and RPE is high, reduce the target by 5-10% and finish the session there. Note it in the comments so your coach can see it.
What you should not do: abandon the session entirely, or grit through at target power with form falling apart. Modified completion beats heroic failure every time.
The weekly view matters more than the daily view
Zoom out from any single workout and look at the week in TrainingPeaks. The weekly TSS total, the pattern of hard and easy days, the progression from last week — this is where fitness is actually built.
A single session is a brick. The week is the wall. The training block is the building. You don't judge a building by one brick.
If your weekly TSS is trending up 5-10% per week during a build, you're progressing. If it's flat for three weeks, you're maintaining. If it's erratic — 450 one week, 280 the next, 520 the next — the training effect is compromised regardless of how good individual sessions were.
What to do next
If you're following a plan and not sure whether it's actually working — or whether you've been stuck for months doing the same sessions with the same results — the Plateau Diagnostic identifies the specific limiter holding you back. Four questions, four minutes, a specific recommendation at the end. Free.