WHO THIS IS FOR
IS THIS YOU?
The rider timing a peak
You've got a target event and want to arrive fresh rather than fried.
The rider confused by the form line
Your TSB is negative and you're worried something's wrong — it usually isn't.
THE ROADMAN VIEW
The Roadman view
TSB is the most actionable number in the whole system, because it tells you not how big your engine is but whether you can use it right now. It's simply fitness minus fatigue, and that subtraction is the whole game of peaking. Through a hard training block your fatigue outweighs your fitness, TSB sits negative, and your legs feel heavy — that's correct, not a problem. You can't build without carrying fatigue.
The magic happens in the taper. Cut the volume, keep a little intensity, and your fatigue (ATL) falls fast while your fitness (CTL) barely moves. The gap opens, TSB climbs through zero into positive territory, and the form you built all those weeks finally surfaces. Watching that line lift into the green is the cleanest confirmation you're peaking by design rather than by luck — and it's the single best antidote to the taper panic that tells you to add a session.
The honest caveat: too much of a good thing is still a problem. Push TSB far beyond about +25 and you've usually shed so much training that the engine has started to shrink — fresh but flat. The target is a band, not a maximum. Land in it and you race at your best.
EXPERT EVIDENCE
WHAT THE EXPERTS SAY
- Joe FrielCo-founder of TrainingPeaks, author of The Cyclist's Training Bible
Form is the relationship between fitness and fatigue, not fitness alone. The reason a taper works is that fatigue clears faster than fitness fades, so a well-timed reduction in load lifts form into a positive range right as the event arrives.
Hear it: The Training Secret To Going FASTER After 40 | Joe Friel
PRACTICAL APPLICATION
DO THIS WEEK
Expect negative TSB while training hard
Through a build block, TSB sitting negative and your legs feeling heavy is normal and correct. Don't try to keep form positive while you're still building.
Use the taper to lift it
In the two weeks before an event, cut volume while keeping a little intensity. Watch ATL fall, CTL hold, and TSB climb toward your target band.
Aim for the band, not the ceiling
Target roughly +5 to +15 for race morning, leaning higher if you're a masters rider who sheds fatigue slowly. Beyond about +25 you've usually over-tapered.
COMMON MISTAKES
WHAT CYCLISTS GET WRONG
MISTAKEWorrying that a negative TSB means something is wrong.
FIXNegative TSB during a training block is exactly right — it means you're carrying the load that builds fitness. Form comes when you taper.
MISTAKETapering until TSB is sky-high.
FIXPast about +25 you've shed too much training and arrive flat. Aim for the +5 to +15 band, not the biggest possible number.
FAQ
FREQUENTLY ASKED QUESTIONS
What TSB should I aim for on race day?
Is a negative TSB bad?
How is TSB calculated?
What does positive TSB feel like?
Can TSB be too high?
Is TSB the same as form?
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