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Workout Intensities Explained

Pick an intensity, get the best structured session for it, and have it on your watch or bike computer in seconds.

Workout intensity is the type of session you want today — recovery, endurance, sweet spot, threshold, VO₂ max, or speed. The six sections below explain each one. On WattX, you choose it in the generator: pick sport, intensity, and duration, and the full workout is built for you — warm-up, work and recovery in the right order (not a random pile of hard minutes), cool-down, and targets in min/100m (swim), watts (bike), and min/km (run). Same zone logic as the rest of the platform, on your watch or bike computer in seconds.

On a WattX Race Plan PRO, the plan label is the intensity (e.g. VO₂ max, threshold). The generator may vary structure inside that band — classic intervals vs micro-blocks, steady threshold vs a descending ladder — while keeping the physiological target aligned with the label.

Each intensity lines up with your Training Zones, from CSS, FTP, and FT on Threshold Testing or the Race Vault.

On WattX

On the generator, choose sport, workout intensity, and duration — your structured workout is ready for your device in seconds.

Bike % FTP below is shorthand; swim and run use the same zones as min/100m and min/km in the generator — see Training Zones.

The Six Workout Intensities

1 · Recovery
~55–65% FTP · Z1–Z2

Active recovery — blood flow without load.

Finish fresher than you started. Day after quality; recovery weeks.

2 · Endurance
~60–75% FTP · Z2

Aerobic base — the foundation of long-course fitness.

Conversational but purposeful. Bulk of base and Ironman volume.

3 · Sweet spot
~88–93% FTP · Z3

Raise the aerobic ceiling efficiently.

2–4 × 10–20 min steady, or occasional descending ladders (88–94% FTP, top rung scales with session length). More stimulus than threshold, lower cost.

4 · Threshold
~95–105% FTP · Z4

Lift sustainable race pace.

3–5 × 6–12 min steady, over-unders, or hard-start reps — or occasional descending ladders (92–100% FTP). Hard but repeatable.

5 · VO₂ max
106%+ FTP · Z5

Expand maximal oxygen uptake.

Mostly 3–6 min at ~105–120% FTP with 1:1 active recovery; ~¼ of sessions use short micro-intervals or 30/15 blocks instead. Peak phase more than base.

6 · Speed
Short Z5 bursts

Neuromuscular power and economy.

Mostly 15–30 s neuromuscular bursts with long recovery; ~30% use longer 45–90 s anaerobic repeats. Targets scale with rep length. Sprint plans use more of this.

How the Week Fits Together

Which intensities dominate depends on distance, phase, and the session’s job — each maps to Zones above.

SPRINT
More Z4–Z5
OLYMPIC
Balanced mix
70.3
Heavy Z2 base
IRONMAN
Z2 dominant

Base emphasises endurance; build adds sweet spot and threshold; peak brings VO₂ and speed; taper cuts volume. Season structure: Race Planning Explained.

Coaching yourself? One or two hard sessions per week across all sports; pair quality days with Brick Sessions when rehearsing race day. On a structured plan PRO, your Plan Page sets each day’s session.

Thresholds First

Structured workouts are only as good as your CSS, FTP, and FT. Test regularly — see How to Test Your Thresholds for protocols — or use a clean race in the Race Vault as your threshold read. Retest or sync every 4–8 weeks so sessions stay on target.

FAQ

How do I choose a workout intensity on a given day?

With a structured training plan PRO, each day’s session is already set on your plan page — matched to phase, volume, race distance, and your thresholds. Without a plan, train by feel and listen to your body.

What is the difference between sweet spot and threshold?

Both are workout intensities. Sweet spot sits in upper Z3 (~88–93% FTP on the bike) with lower fatigue cost. Threshold targets Z4 (~95–105% FTP). In a training plan, both fit well in build phases, but threshold is usually more taxing.

Can I do VO2 max in all three sports?

Yes, but recovery cost differs — swim is demanding but non-impact, bike is most manageable, run requires the most recovery and carries the highest injury risk.

How long should a recovery session be?

30–45 minutes is usually enough. Longer easy work adds fatigue instead of clearing it.

Where does strength fit?

Strength is great for functional durability and complements cardiovascular training. Use the generator for simple, efficient strength workouts — short sessions, few movements, on purpose.

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