You've done the work. Twelve weeks of it, maybe sixteen. The long rides, the threshold blocks, the early mornings on the trainer when the rain was sideways. And now you're two weeks out from the event you built all of it for, and a quiet panic sets in. You feel like you're not doing enough. You want to cram one more big session in, just to be sure.
Here's what nobody tells you about the final fortnight: it's the part most amateurs get wrong, and it's the part that decides whether all that training actually shows up on the day. The taper isn't where you build fitness. It's where you reveal it. And the cleanest way I know to get it right is to stop tapering on feel and start tapering off the Performance Management Chart in TrainingPeaks.
Three numbers, one decision
If you log your rides with power, TrainingPeaks gives you the Performance Management Chart — the PMC — and it runs on three numbers. Get comfortable with these and the taper stops being a guessing game.
CTL — Chronic Training Load. This is your fitness. It's an exponentially weighted average of your training stress over the last 42 days, so it moves slowly. Months of consistent work push it up; a couple of easy weeks let it drift down. Think of it as the size of the engine you've built.
ATL — Acute Training Load. This is your fatigue. Same idea, but over the last 7 days, so it moves fast. A big weekend spikes it; a few rest days drop it like a stone. Think of it as how tired you are right now.
TSB — Training Stress Balance. This is the gap between the two — yesterday's CTL minus yesterday's ATL — and it's your form. When TSB is deeply negative, you're buried under fatigue. When it climbs positive, the fatigue has cleared and the fitness is still there. That positive number is the feeling of fresh, snappy legs, quantified.
A taper, read through the PMC, is one sentence: hold CTL roughly steady, let ATL fall away, and watch TSB swing positive for race day. That's the whole thing. Everything else is detail.
What the chart should look like
Picture the two weeks before your event on the chart. Your CTL line is near its seasonal peak — that's the fitness you've banked. Your ATL line, through the hard final block, has been sitting above it, which is why your TSB has been negative and your legs have felt heavy. That's normal. You can't build fitness without carrying fatigue.
Now you start the taper. You cut the volume hard — 40 to 60% off your normal weekly hours — but you keep the intensity. The long rides shrink. The easy junk miles disappear. What stays is a couple of short, sharp efforts to keep the system primed.
On the chart, the ATL line drops fast because you've pulled the volume. The CTL line barely moves, because 42 days of averaging means two quiet weeks only nudges it down a point or two. And as the gap between them opens up, the TSB line lifts off the bottom, crosses zero, and climbs into positive territory. You watch your form arrive, day by day, on the screen.
That visible climb is the single best antidote to taper panic I've found. When the voice in your head says you're losing fitness, do more, the CTL line is right there telling you it hasn't moved. The freshness you're feeling isn't fitness draining away. It's the adaptation finally surfacing.
The numbers that matter for race day
So where do you want to be on the morning of the event?
For most riders, a race-day TSB of around +5 to +15 is the sweet spot. Positive enough that the fatigue is gone, not so positive that you've thrown away training. There's good evidence behind the broad shape of this: the Bosquet meta-analysis in Medicine & Science in Sports & Exercise found the strongest taper effect came from a two-week taper with volume cut 41–60% and intensity held — worth roughly 2–3% in performance. On a 60-minute climb, 3% is nearly two minutes. That's not a marginal gain. That's the difference between a result and a story about what might have been.
If you push TSB much beyond +25, you've usually gone too far — you've shed so much load that the CTL line has started to sag and you arrive fresh but flat, with no snap. The art is landing in the band, not overshooting it.
And here's the part that matters for the riders I work with most. If you're a masters rider — and a lot of you reading this are the wrong side of 45 — you almost certainly need the higher end of that range. Older riders shed fatigue more slowly. The same volume cut that brings a 28-year-old to +8 might only bring you to zero. When I had Professor Stephen Seiler's principles in mind building masters plans, the recurring theme is that recovery is the variable that changes most with age, not the work itself. So if you're 52, plan your taper to land TSB around +12 to +18, and don't be afraid to rest more than feels comfortable in the last four days.
The three mistakes the chart catches
Almost every botched taper is one of three errors, and all three are visible on the PMC before they cost you anything.
Tapering too early. You get nervous, back off with three weeks to go, and the CTL line starts bleeding down well before the event. You arrive fresh but detrained — form is high, but the engine has shrunk. The fix is to hold your training until roughly two weeks out and trust the chart, not the nerves.
Tapering too aggressively. You don't just cut volume, you cut intensity too, and you stop riding hard entirely. The body reads this as detraining. Leg speed goes, the top-end snap disappears, and you turn up flat. On the chart your TSB might look gorgeous, but the quality is gone. Keep the intensity. A 2x20 threshold session becomes a 2x10. A 4x4 VO2 session becomes 2x4. Short, but sharp.
Not dropping fatigue enough. This is the most common one. You taper in your head but not in your training — you keep sneaking in volume because stopping feels wrong. ATL never falls far enough, TSB stays stuck near zero or negative, and you race tired. If you're 48 hours out and the chart still shows negative form, that's the chart telling you to rest, hard, right now.
A fortnight, in numbers
It helps to see it concretely. Say you finish your last hard block with a CTL of 70 and an ATL of 85. Your TSB is sitting at around -15 — buried, legs heavy, exactly where a final build should leave you. The fitness is banked; the fatigue is masking it.
Week one of the taper, you cut volume to 60% of normal. Over seven days your ATL falls fast — down to the low 60s — while your CTL barely moves, dipping a single point to 69. The gap opens, and your TSB climbs to around +5. You already feel the difference.
Race week, you cut to 40% of normal volume, keeping only a couple of short, sharp openers. ATL keeps dropping into the high 40s, CTL eases to 67, and on race morning your TSB is sitting around +15. That's the band. Fitness almost entirely intact, fatigue cleared, form clearly positive. You didn't guess your way there — you watched it happen, day by day, on the chart.
How to actually run it
Here's the simple version you can apply to your next target event.
Two weeks out, your CTL should be at or near its peak — that's your last week of full training. From there, cut weekly volume to about 60% of normal in week one and 40% in race week. Keep one or two quality sessions each week, shortened but at full intensity. Fill the rest with easy spinning and rest days. Do not add anything. The work is done.
Then watch the chart. You want to see ATL falling steadily, CTL holding within a point or two, and TSB climbing toward your target band as race day approaches. If the form line is lagging, rest more. If it's already well past +20 with days to go, you've over-tapered — add a short, sharp session to bleed off a little of that excess freshness.
The riders inside the Not Done Yet community run their whole build and taper through TrainingPeaks for exactly this reason. The taper is the moment in the season where seeing the numbers beats feeling your way through it. You stop asking am I fresh enough? and start reading the answer off the screen.
You did the hard work weeks ago. The taper is just the discipline to let it surface. Get the chart right, and you'll stand on the start line knowing — not hoping — that the legs are there.
Want the build that earns a taper like this? The tapering guide covers the session-by-session protocol, and reading your training data is the field guide to CTL, ATL and TSB if those acronyms are still new. If you'd rather have the whole season built and adjusted around your data, come and find us on Skool.