Tapering

Tapering is the 1–3 week unloading period before a race: volume drops by 40–60% while intensity is kept, so fatigue clears and fitness shows on race day.

Definition

“Tapering” is the deliberate reduction of training load in the last one to three weeks before an important race. It follows the build phase or a final peak week and is the last of the training phases before the event.

The goal is not rest for its own sake but revealing fitness: the fatigue accumulated during the build should clear without fitness declining. That is why volume is cut while intensity is maintained.

Why it matters

Fitness and fatigue overlap. At the end of the build phase, fitness is at its highest, but visible performance is dampened because fatigue masks it. Tapering exploits the fact that fatigue disappears faster than fitness.

The meta-analysis by Bosquet and colleagues (2007) puts the performance gain from a well-planned taper at around 2–3%. That sounds small, but over a half distance it equals several minutes. Too little unloading wastes this gain; too much costs fitness.

Structure and signals

Feature	Typical value
Duration	7–10 days for short races, 2 weeks for half and full distance, rarely 3
Volume	`−40–60%`, progressive or in steps
Intensity `Z1/Z2/Z3`	`70/10/20`, share is kept, sessions get shorter
Frequency	at most `−20%`, the rhythm is preserved
Last hard session	4–6 days before the race, short

Signs the taper is working: legs feel snappy, output in short race-pace segments rises while heart rate falls, HRV climbs above the range of the build phase, sleep and mood improve.

Signs it has gone on too long: heaviness does not disappear but is replaced by sluggishness, short intervals feel unusually hard, or heart rate at easy pace is strikingly low while perceived effort is high. Then either the reduction was too steep or the phase too long.

How obseed measures it

obseed compares the load of the taper weeks with the average of the previous four weeks and shows the reduction as a percentage. What matters is that intensity stays anchored to the thresholds measured in your diagnostics: a race-pace session that actually takes place in Z2 instead of at VT2 does not preserve fitness.

In parallel, obseed tracks resting heart rate and HRV from your wearable. Rising HRV above baseline with falling resting heart rate is the expected pattern. If it does not appear, the reduction may be too small or the fatigue sits deeper than planned.

The success of “Team Norway” at the 2022 Ironman World Championship in Hawaii, where the athletes rode nearly the full bike distance at race intensity one week before the event, shows how individual tapering can be. Without years of lead-up and full recovery options it cannot be copied in amateur sport, but it should certainly be measured.

Example

Two-week taper of a triathlete before a half distance, build volume 12 hours:

Week	Volume	Reduction	Key sessions
Race −2	8 h	`−33%`	Bike 3 × 10 min race pace, run 4 × 5 min at VT2, long session 2.5 h
Race −1	5 h	`−58%`	Bike 2 × 8 min race pace on Tuesday, run 3 × 3 min on Wednesday, easy only from Thursday

Distribution in both weeks 70/10/20. The day before the race, 30 minutes easy with three short strides so the body keeps its rhythm. After the race, the recovery phase begins.

References

Mujika, I. & Padilla, S. (2003). Scientific bases for precompetition tapering strategies. Medicine & Science in Sports & Exercise, 35(7), 1182–1187.
Bosquet, L., Montpetit, J., Arvisais, D. & Mujika, I. (2007). Effects of tapering on performance: a meta-analysis. Medicine & Science in Sports & Exercise, 39(8), 1358–1365.