What does "I can run flat out for a half mile before my hands start shaking" mean?

It was said in The Bourne Identity.

I am not a native English speaker. I know the meaning of the individual words, but have never heard the expression "run flat out" before.

  • General Reference - flat out - at top speed; "he ran flat out to catch the bus" Jan 29, 2014 at 6:04
  • I have retracted my earlier closevote. per comments under binarysubstrate's answer, although I still think the headline question (what does it mean here?) is GR, the etymology of how the idiomatic flat-out came to have two now-distinct senses (at top speed and bluntly, truthfully) seems less clear-cut. Jan 29, 2014 at 13:38

3 Answers 3


Flat out is an expression used to describe one of three things, depending on the context:

  1. Doing something as hard or as quickly as you can: e.g. I worked flat out to finish the assignment.
  2. Doing something without hesitating or any second thought: I flat-out disagree with your view.
  3. Lying down completely stretched out: After winning the race, I was exhausted and collapsed flat-out on the ground.

In this case, it's the second or the first use, depending on the context, though in either case he's making a statement about his physical condition. The speaker is saying one of two things:

  1. He can run as quickly as he can for half a mile before his hands start shaking
  2. The speaker can, without a moment's hesitation, run half a mile, without a warm-up, before his hands start shaking.
  • You're not 100% wrong, but it's misleading to suggest that #2 might apply at all in OP's context, let alone to mention is first. Besides which, your paraphrasing "He can run as quickly as he can" simply isn't a credible utterance. Jan 29, 2014 at 6:10
  • Thank you. I believe that #1 makes more sense in the context of the movie. Jan 29, 2014 at 6:24
  • Yes, #1 is the correct interpretation. The protagonist has an erased memory and is surprised to find out he has great physical training. Running flat-out for half a mile would send most people gasping for air :)
    – oerkelens
    Jan 29, 2014 at 9:01


Flat-out is an idiom which can be used in several contexts as already written by @newb. In the context of the original question it means to go at a maximum speed. Merriam-Webster offers several definitions online (listed under "flat out" and "flat-out") including:

  1. informal (chiefly US): Absolute and complete.
  2. Greatest possible. Maximum.


@ws2 indicated flat-out may have originated with automobiles and specifically references having your foot flat on the accelerator pedal, similar to the phrase “Put the pedal to the metal.”

@oldcat indicated the origins may derive from horse racing where a rider or jockey must lie as flat as possible during a race to decrease wind resistance.

Intuitively both of these ideas seem plausible. However, if any origin is officially recognized, I haven’t found a reference to it yet.

(Rewritten based on comments.)

  • I'm afraid that's totally the wrong sense wrong for OP's context. Jan 29, 2014 at 6:06
  • Don't be daft. Of course it has a definition. Probably several, but the dictionary I linked to under the question gives two. The one which I copied into my comment is the one that applies here. Yours is the other, which doesn't. Jan 29, 2014 at 6:14
  • I don't know what I'm supposed to do with that link. Would it help you to know that OED definitely has the relevant definition, but appears not to explicitly include your honestly, bluntly sense at all. Which I'm sure is in any case a derivative of at top speed -> quickly -> directly -> bluntly -> truthfully (nothing to do with "lying flat, spread out, on the ground"). Jan 29, 2014 at 6:35
  • 1
    @FumbleFingers I haven't looked up the OED, but I always assumed 'flat-out' started in the age of the motor car. It is about having your foot flat on the accelerator pedal, isn't it? Australians, when overworked, will say 'I'm flat to the boards with so-and-so job'.
    – WS2
    Jan 29, 2014 at 7:17
  • 1
    There could be another derivation of flat-out from horse racing. To achieve top speed the rider lies as flat on the horse as possible to decrease wind resistance.
    – Oldcat
    Jan 30, 2014 at 1:34

The only form that clearly makes sense is the Australian version that dates at least as far back as WWII: "Flat out like a lizard drinking." The implication of speed is from the lizard's tongue rapidly lapping up the water, which gets totally lost when shortened to just "flat out."

  • 1
    But that is not the original version. The expression "flat out" dates back to at least 1932, from England according to the OED. And it makes sense etymologically by itself because we also say "go all out".
    – Laurel
    Nov 7, 2019 at 2:30
  • (1) The question asks “What does ‘flat out’ mean?”  It means “at top speed”.  How is your answer to the question of meaning any different from the one that has been posted twice before?  (2) Are you claiming that this is the source of the idiom?  How does that make sense?  Why would anybody say “Flat out like a lizard drinking” unless “flat out” already meant “at top speed”?  (3) Are you saying that the “car” and “horse” explanations don’t “make sense”?  If so, why not? Nov 7, 2019 at 4:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.