Run Out of Steam
Pedagogically reviewed by LexFizz Team
To lose energy, enthusiasm, or momentum; to no longer have the power or motivation to continue.
Quick meaning: To run out of steam is to lose your energy, enthusiasm, or momentum, so that you can no longer keep going or finish what you started.
Meaning
To run out of steam means to gradually lose the energy, enthusiasm, or driving force needed to keep doing something. When a person, project, campaign, or conversation runs out of steam, it slows down and loses momentum until it eventually stops or fades away.
The idiom can describe physical tiredness — like a runner who runs out of steam near the finish line — or a loss of motivation and interest. It is also used for plans, movements, and trends that start strongly but then lose their force and fizzle out.
The phrase usually carries a slightly disappointed tone, suggesting that something promising has weakened. The opposite idea would be to “pick up steam” or “gain momentum.”
Origin
This idiom comes directly from the age of steam engines. Locomotives and other steam-powered machines burned coal to heat water and produce steam, and that steam provided the pressure that drove the engine forward. When a locomotive ran out of steam — because the fire died down or the water ran low — it literally lost its driving power and slowed to a halt.
From this very real mechanical event grew the figurative meaning. Just as an engine without steam cannot keep moving, a person or project without energy and enthusiasm cannot keep going. The expression entered everyday English during the 19th and 20th centuries, as steam power shaped daily life across the industrial world. Learners who want to check other figurative expressions can consult general reference works such as the Cambridge Dictionary, which document how such idioms are used today.
The image is easy to picture, which is part of why the idiom remains so common today, long after steam locomotives became rare.
Example Sentences
I started the marathon strongly, but I ran out of steam in the last few miles.
The campaign began with great energy, but it ran out of steam once the funding dried up.
We were full of ideas at first, but by the afternoon the whole team had run out of steam.
Dialogue Example
A: Did you finish painting the spare room?
B: Almost — I did three walls and then completely ran out of steam. I’ll finish the last one tomorrow.
Usage Notes
This idiom is informal to neutral and very common in both British and American English. It works for people, projects, campaigns, conversations, and trends. It is often used in the past tense (“ran out of steam”) to describe something that already lost its momentum, and it usually carries a faintly disappointed tone.
Common Mistakes
Learners sometimes say “run out from steam” or “run out the steam” — the correct form is “run out of steam.” Also, do not confuse it with “let off steam,” which means to release pent-up energy or emotion, not to lose energy. The two idioms look similar but mean different things.
Related Idioms
Practise English Idioms
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Quick Check: Run Out of Steam
2 questions — test what you just learned.
1. What does “Run Out of Steam” mean?
2. Complete the sentence: “We were full of ideas at first, but by the afternoon the whole team had _____.”
Frequently Asked Questions
What does “run out of steam” mean?
It means to lose energy, enthusiasm, or momentum, so that you no longer have the power or motivation to continue what you were doing.
How do you use “run out of steam” in a sentence?
You can say “I ran out of steam halfway through the project” or “The campaign ran out of steam,” meaning the energy or momentum faded away.
Where does “run out of steam” come from?
It comes from steam engines. When a locomotive ran out of steam, it literally lost its driving power and slowed to a halt. The figurative meaning grew from this during the 19th and 20th centuries.
What is the correct preposition in this idiom?
The correct form is “run out of steam.” Avoid saying “run out from steam” or “run out the steam,” which are incorrect.
What is the opposite of “run out of steam”?
The opposite is to “pick up steam,” “gain momentum,” or “build up steam” — to grow in energy and force rather than lose it.
Is “run out of steam” the same as “let off steam”?
No. “Run out of steam” means to lose energy, while “let off steam” means to release pent-up energy, stress, or emotion. They look similar but mean different things.
Is “run out of steam” formal or informal?
It is informal to neutral and very common in everyday speech and writing. It fits casual and semi-formal contexts well.
Can it describe projects as well as people?
Yes. It can describe people losing energy or motivation, and also projects, campaigns, conversations, or trends that lose their momentum and fade out.
What are common collocations with “run out of steam”?
Common patterns include “ran out of steam halfway through,” “quickly ran out of steam,” and “the project ran out of steam.”
What English level is “run out of steam” suitable for?
It is pitched at B1 (Intermediate) level. The words are simple, and the steam-engine image makes the figurative meaning easy to grasp.