How do I pace a time trial effectively?

Time trial pacing is the art of turning your best possible effort into the fastest possible speed. That means using your power where it buys the most speed and saving it where extra watts barely move the needle. The best pacing plans blend physics, your physiology (FTP, critical power, W’), and the course profile.

The goal: fast speed, not perfectly steady power

Even pacing does not mean flat power the whole way. Because air resistance rises roughly with the cube of speed, an extra 20 watts on a fast descent barely changes your time, while the same 20 watts on a climb or into a headwind can be worth seconds.

• Use more power where speed is limited: climbs, headwinds, rough surfaces, tight sections out of corners.
• Use less power where speed is already high: tailwinds and fast descents.
• Avoid big spikes out of corners or on short rises; surge control saves matches and keeps cadence smooth.

Think of the course as a series of segments. Your job is to move a few percent of your average power from low-payoff segments to high-payoff segments while staying inside a sustainable physiological envelope.

Set your targets with FTP, critical power, and W’

Two practical anchors for pacing are FTP (your best sustainable power for around an hour) and the critical power model, which splits performance into:

• Critical power (CP): the power you can theoretically sustain without drawing down your finite anaerobic work capacity.
• W’ (W prime): your finite “battery” of anaerobic work (kJ) that you spend when you ride above CP and partially recharge when you ride below CP.

Use these to set realistic targets by duration:

• 10–20 minutes: ~105–115% of CP (roughly 108–120% of FTP for many riders).
• 20–35 minutes (10–20 km TT): ~100–107% of CP (about 102–110% of FTP).
• 35–60 minutes (25 km–40 km): ~95–102% of CP (about 97–105% of FTP).

These ranges assume good aero position and a proper TT warm-up. Individual responses vary—use recent race efforts or well-executed tests to refine your personal targets.

Distribute power over the course

Start with a course map and wind direction. Mark climbs, head/tailwinds, technical corners, and any rough sections. Then assign relative power targets around your overall average.

Starts and corners

• Start: 30–60 seconds at ~103–108% of your target average power to get up to speed, then settle. Avoid >120% spikes.
• Corners: Brake early, exit cleanly, and accelerate smoothly back to target. Aim for 5–10 seconds slightly above target, not a 400–600 W sprint.

Hills and headwinds

• Short climbs (≤2 minutes): +5–10% above target power; cap at ~CP + 20–40 W if you want to protect W’.
• Longer climbs (3–8 minutes): +3–6% above target, staying near CP to avoid deep W’ depletion you cannot repay.
• Headwinds: Treat like gentle climbs. +3–8% above target depending on length; longer headwind = smaller bump.

Descents and tailwinds

• Fast descents: -10–25% below target. If you exceed ~65–70 km/h, extra watts are almost free speed wasted—tuck and focus on aero.
• Tailwinds: -5–10% below target; keep cadence smooth and aero tight.

The final kilometre

• With 1–2 minutes to go: lift to ~105–110% of your average target, then kick in the last 30–45 seconds if you have W’ left.
• Finish with a controlled rise, not a fade. If you cannot lift, your earlier segments were too hot.

A simple energy model you can use (CP/W’)

The CP/W’ framework helps you allocate surges. Above CP you spend W’; below CP you partially recover it. A rough planning guide:

W' spent over a segment ≈ max(0, Power - CP) × time (in seconds)  [units: joules]

Example: CP = 280 W, W' = 18,000 J
- 45 s at 320 W: (320 - 280) × 45 = 1,800 J
- 90 s at 330 W: (330 - 280) × 90 = 4,500 J
Total spent so far = 6,300 J (about 35% of W')

Below CP, W’ replenishes over time. The recovery is not 1:1; it follows kinetics that depend on how far below CP you ride and for how long. Practical rules of thumb:

• Plan only a few above-CP efforts totaling no more than ~60–70% of your W’ before the final push.
• Use long descents/tailwinds at 80–95% of CP to claw back some W’ before the finish or the next hill.
• If a surge would push W’ below ~20–30% remaining with more than a few minutes to go, trim it.

In this example you budget most of your W’ for meaningful segments and preserve enough for a controlled finish. If you find you cannot lift in the last minute during practice runs, reduce earlier surges by 5–10 W.

Execution checklist and common mistakes

• Warm-up: 20–30 minutes with 2–3 short efforts to near target power so oxygen kinetics are primed.
• Head unit: Show 3-second power, lap average power, and distance remaining. Use HR or RPE as a cross-check; both lag early.
• Cadence and gearing: Choose a cassette that keeps you in your preferred cadence on climbs and descents to avoid torque spikes.
• Aero first: Hold your position under pressure; a steady aero shape often beats 5–10 extra watts with a bobbing head.
• Fuel and hydration: For efforts ≤60 minutes, arrive topped up; a small carbohydrate sip is fine but do not fumble bottles.

Common mistakes:

• Starting 20–30 W too hard in the first 2 minutes and burning through W’.
• Chasing speed on fast descents instead of tucking and saving watts.
• Ignoring wind direction when setting segment targets.
• Overfocusing on instant power; ride the 3–10 second average and the course plan.

Putting it together: a quick template

1. Set overall target based on duration: e.g., 40k in 60 minutes → ~98–102% of CP.
2. Mark segments: climbs/headwinds (+3–8%), descents/tailwinds (−5–20%).
3. Budget W’: identify 2–4 meaningful above-CP surges; keep ~30–40% in reserve for the last 5–8 minutes.
4. Practice on similar terrain and refine targets by ±5–10 W from how you finish.

With a clear plan, controlled surges, and an eye on your W’ budget, you will convert more of your fitness into speed and finish your time trials fast—and upright—every time.