Triathlon Taper Calculator
Enter the fitness and fatigue you already track — CTL and ATL — plus the peak weekly TSS you're coming down from, and get a week-by-week taper that lands your race-day form (TSB) in the sweet spot of +15 to +25.
Taper length
Projected race-day form (TSB)
+23
Target sweet spot: +15 to +25
Race-day CTL
65
fitness
Race-day ATL
42
fatigue
Your taper schedule
Volume drops week over week while fatigue clears faster than fitness, lifting your form into the race-ready band. Hold short, sharp intensity through the taper so you stay race-sharp, not sluggish.
How to use it
- 1Enter your current CTL (fitness) and ATL (fatigue) — read them off your dashboard or the Fitness, Fatigue & Form chart.
- 2Set the peak weekly TSS you're tapering down from.
- 3Choose a 1-, 2-, or 3-week taper.
- 4Read your projected race-day form (TSB) and the week-by-week TSS schedule that gets you there.
A good taper sheds fatigue faster than fitness
Your form (TSB) is fitness minus fatigue — CTL minus ATL. Fatigue is a 7-day moving average and fitness is a 42-day one, so when you cut volume, ATL collapses roughly six times faster than CTL fades. That gap is the whole point of a taper: a few light weeks let fatigue evaporate while you keep almost all the engine you spent months building. This calculator rolls both averages forward day by day so you can watch that gap open and land your form where it should be on race morning.
It's the same taper solver that builds your plan
PaceBeats runs this exact projection when it shapes the final weeks of your season — rolling your CTL and ATL through each taper week and scaling the load until race-day TSB hits the target band. The schedule you see here is a faithful preview of how the coaching engine tapers you, not a generic percentage chart bolted on for SEO.
Aim for +15 to +25 TSB, not zero training
Detraining is real: stop training entirely and CTL slides while ATL bottoms out, leaving you flat and over-rested above +25. Taper too little and you toe the line still buried in fatigue below +5. The +15 to +25 band is the freshness most age-groupers race their best on, so this tool scales your taper up or down until your projected form lands inside it.
How the math works
The calculator seeds a descending taper from your peak weekly TSS — for a two-week taper, 60% then 40% of peak — and rolls your CTL and ATL forward one day at a time with the same exponentially-weighted moving averages the dashboard uses: a 42-day time constant for fitness and a 7-day constant for fatigue, with each week's TSS spread evenly across its seven days. Because fatigue decays about six times faster than fitness, cutting volume opens a positive gap and your form (TSB = CTL − ATL) climbs. It then scales the whole taper ±8% per pass, up to three passes, until projected race-day TSB lands inside the +15 to +25 band. This is the identical EWMA and taper-solver logic PaceBeats runs when it builds the last weeks of your season, so the schedule here mirrors how the engine would taper you.
Built and reviewed by the PaceBeats coaching-engine team. Every calculator runs the same sports-science math that powers the app's adaptive plans.
Common questions
How long should my triathlon taper be?
Match the taper to the race. A sprint or Olympic needs about one week; a 70.3 settles best on a two-week taper; an Ironman usually wants the full three weeks because its training load is so deep that fatigue takes longer to clear. The longer the event and the bigger the block you're coming off, the more taper you need — set the length here and watch where your projected form lands.
How much should I cut training volume during taper?
Cut volume hard while holding intensity. This tool drops to roughly 50-60% of peak weekly TSS in the first taper week and 40-50% by race week, keeping short, sharp efforts so you stay race-sharp instead of going sluggish. The key is shedding TSS, not skipping quality — that's what drives fatigue down without letting fitness slide.
Next step
Turn these numbers into an adaptive plan.
PaceBeats uses this exact math — and your training history — to build and adapt your swim, bike, run, and strength week after week.