CyclingEnduranceIntermediate 185 min

Cycling durability: 2 h 30 endurance and 2 × 10 min at threshold

A cycling durability session: 2 h 30 of endurance at 60–70% of FTP, then two 10-minute efforts at 95–100%, ridden on tired legs. 3 h 05 in all. For training your ability to produce power after hours in the saddle.

Written by Pierre Halloo · Updated 25 October 2026

Session profile6 blocks

At a glance

Duration: 185 min
Main target: 95–100%FTP4 Z4 · Threshold
Time at target: 20 min
Estimated load: 142
Structure: 140′ at 60–70% FTP
Level: Intermediate
Equipment: Power meter

The session in detail

FTP

Time in zone

Z125 min
Z2140 min
Z420 min

What the targets mean

The session's targets, in watts for three reference FTPs
Target	Zone	Time	FTP 200 W	FTP 250 W	FTP 300 W
95–100%	4Threshold	20 min	190–200 W	238–250 W	285–300 W
60–70%	2Endurance	140 min	120–140 W	150–175 W	180–210 W
50–60%	1Recovery	15 min	100–120 W	125–150 W	150–180 W

Put this session on your bike computer or watch

Wattson works out the targets from your FTP and sends the session to your Garmin, Wahoo, Coros or Suunto.

Try this session

What this session is for

Your thresholds measured on fresh legs don't last all day: over a long effort, the power you can sustain drops, faster for some riders than others. Researchers call the ability to limit that drop 'durability'. And it's often after three or four hours that a road race or a mountain sportive is decided.

Putting two threshold efforts at the end of the ride gets you used to working in that state, and shows you your real level late in a race. The concept is well established; whether this kind of session improves durability has not been shown. No standard training format was found.

Who it's for

Riders preparing for long races or sportives, with a solid endurance base: 3-hour rides should already be familiar. You need a recently measured FTP to set the endurance and the final efforts.

When to do it

It's your long ride of the week, not an extra session: once a week or every other week is a common guideline in the weeks before a long event. Keep the next day easy. To progress, lengthen the endurance part towards 3 hours.

How to do it

Warm-up
10 min
10′ at 50–60% FTP
10 minutes at 50–60% of FTP, or 125 to 150 W for an FTP of 250 W. The endurance ride serves as the warm-up: nothing more needed.
Main set
140 min
140′ at 60–70% FTP
2 h 20 of endurance at 60–70% of FTP, or 150 to 175 W. You should be able to talk. Eat and drink throughout, as on event day: roughly every 20 to 30 minutes. Running short of carbohydrate would distort the final efforts and raise the risk of bonking.
Main set
25 min
2 × 10′ at 95–100% FTP, 5′ recovery
Two 10-minute efforts at 95–100% of FTP, or 238 to 250 W, with 5 minutes at 50–60% between. They'll feel harder than usual at the same power: that's the point. If you can't hold the target, finish at 90% rather than abandoning the effort. Note your average power and heart rate: they're your benchmarks for next time.
Cool-down
10 min
10′ at 40–55% FTP
10 very easy minutes at 40–55% of FTP. Eat within the hour: you've ridden more than three hours.

How it should feel

The endurance stays easy for a long time, then your legs get heavier in the last hour. The first threshold effort is a shock: the same power as on fresh legs feels far more costly. The second is a mental game. Guide: 3 to 4 out of 10 for the endurance, 8 out of 10 on the final efforts.

Common mistakes

Not eating

Without carbohydrate for 2 h 30, your final efforts mostly measure your lack of fuel, not your durability. Eat and drink regularly, as in a race.

Riding the endurance too hard

Endurance ridden at tempo leaves you empty for the final efforts, and the ride turns into a three-hour hard session. Stay at 60–70%: the fatigue should come from duration, not intensity.

Doing the efforts too early

Two threshold efforts after an hour is a normal ride with intervals. The whole point is to do them late, on legs that have already been working for a long time.

Treating it as an extra session

Durability replaces your long ride of the week. Added to an already busy week, it tires you enough to spoil the sessions that follow.

When to skip it

Before you start

A recently measured FTP.
Familiarity with 3-hour rides.

Skip it if

You're coming back after a break, or your endurance base is still short.
A hard session or race is planned for the next day.

Origin and evidence

Level of evidence

Limited evidenceLevel 2 of 5

The concept of durability was formalised by Maunder and colleagues (Sports Med 2021): the time of onset and magnitude of the deterioration in physiological characteristics over prolonged exercise. A 2025 review (Hunter and colleagues) points out that nutrition and environment strongly influence these measures. No standard training format for durability was found: this session is a Wattson choice, from the endurance duration to the final efforts, as is the advice to finish at 90% if the target doesn't hold. It isn't established that this kind of session improves durability. Bottom line: good evidence on the concept, weak on the format.

Sources

Maunder E. et al., Sports Med 2021
Hunter B. et al., revue sur la durabilité, 2025

Frequently asked questions

What is durability in cycling?

It's your ability to limit the drop in performance over a long effort. Your FTP measured on fresh legs doesn't count for much after four hours on the road: a 'durable' rider keeps more of it. The term was formalised by researchers in 2021.

What power for this session?

For the endurance, 60–70% of FTP: 120 to 140 W for an FTP of 200 W, 150 to 175 W for 250 W, 180 to 210 W for 300 W. For the final efforts, 95–100%: 190 to 200 W, 238 to 250 W, 285 to 300 W.

Does this session really improve durability?

That hasn't been shown. The durability concept is solid, but no study has established how to train it. The session at least has a practical use: it shows you what you're worth late in a race, and teaches you to eat and pace over a long day.

Should I do it outdoors?

It's easier: three hours on the turbo is a long time, and the road is closer to the event. On a turbo the session is still doable, with plenty to drink and good airflow. The watt targets are the same.

Take it up a level with Wattson

An intuitive workout editor to build cycling and running sessions in no time, then sync them to your watch or bike computer: Wahoo, Garmin, Suunto or Coros.