I mean a average human can run at his full speed for 15 to 20 mins before getting tired. Trained athletes can go on running for much more time without tiring out.

Do Superheroes like Quicksilver or Flash ever get tired due to excessive running?

  • Depends on the hero. Flash pre-SpeedForce got tired and needed lots of rest, post-SpeedForce he's always charged up. Commented Feb 19, 2015 at 13:30
  • In the latest episode of The Flash, Barry actually says "that was a lot of running" and is visibly exhausted from it. So yes, they do get tired.
    – Robert
    Commented Feb 19, 2015 at 20:59
  • 4
    Is it just me, or is the statement, "...a average human can run at his full speed for 15 to 20 mins before getting tired" just totally crazy? Most people would have trouble maintaining a sprint for more than a minute.
    – D34DM347
    Commented Oct 7, 2015 at 20:04
  • 2
    At a sprint most people would gas-out after a few seconds, not minutes.
    – Morgan
    Commented Feb 22, 2016 at 16:19
  • Flash needs to eat a lot.. Like too much. When he skips meals, his stamina decreases.
    – user931
    Commented Oct 13, 2018 at 17:13

2 Answers 2



According to Marvel's previously posted bio, Quicksilver did have limited endurance prior to his new Terrigen Crystal-based powers.

Quicksilver possessed superhuman speed, and could travel on foot at speeds exceeding the speed of sound for hundreds of miles before tiring;

Since getting his new powerset, he still has limited endurance.

His molecular speed that he generates displaces him out of the mainstream time/space so that he is able to propel himself into the future. He can leap from thirty seconds to up to twelve days, and remain for several minutes to several hours before being recalled to his present time once his body tires, or he can return at will before his time is up.

The Flash

Most (maybe all - and there's a lot) of the versions of The Flash are listed as having Superhuman Endurance, which is described as

Sometimes called "enhanced endurance", Superhuman Endurance is a term used to describe the ability of some characters to never get tired. Their bodies metabolize at a rate that far exceeds normal humans allowing them to continue in their task for an incredible amount of time.

I can find no reference to the comics versions of The Flash becoming fatigued.

The exception, however, seems to be the current live-action version, who does become fatigued at times. It can be noted, however, that this version of Barry Allen is still in training and has been increasing his maximum speed and endurance through the course of the show.

  • TV Flash doesn't seem to tire from running so much as the physical exertion afterwards. e.g. he zips back and forth from Central City and Star[ling] City and isn't winded, but subsequently fighting someone wears him down. Mostly, he just gets hungry.
    – KutuluMike
    Commented Feb 19, 2015 at 14:11
  • 2
    One major exception that should be added to this answer: unusual exertion. The Flash is routinely shown to be winded after having to seriously "step up" his speed, or run an unusual distance (like around the world 12 times or something). Innumerable instances in the comics and cartoons have him running as fast as he possibly can to get a bomb out of range of civilians before it goes off, or something similar, and when he finally does, he's shown bent over and panting. He seems to be able to "jog" infinitely, but sprinting or exerting himself does consistently wear him out.
    – Nerrolken
    Commented Feb 19, 2015 at 17:36
  • @MichaelEdenfield, actually, in the most recent episode, Barry has to create a vacuum to save himself, for a reason I won't reveal. After he has succeeded, he is visibly exhausted and even states breathlessly "that was alot of running".
    – Robert
    Commented Feb 19, 2015 at 21:02
  • Off the hat I can think of a few instances of Flash having to catch his breath after extreme bursts of speed, like @Nerrolken pointed out. After escaping Omega beams (Justice League #5, 2011) for instance.
    – Jenayah
    Commented Oct 13, 2018 at 16:55

Why do we get tired on running:

What exactly is the mechanics behind getting tired?

  1. Muscle tissue breakdown: Exercise strains and breaks certain amount of muscle fibers with each iteration. We feel our muscles tired because there isn't enough active muscle tissue. This is basically how exercising works. The muscle builds up stronger next time.
  2. Accumulation of metabolites: Muscles are unable to function after working out because they are swimming in waste products of the biochemical process that enables them to concentrate. These need to get metabolized before the muscle can work normally again.

Now Speedsters like QuickSilver, & The Flash have heightened metabolism & regenerative abilities. Reference Indicates this.

Now considering their abilities, let us look again at our reasons for fatigue.

  1. Tissue breakdown: The Speedsters enhanced regenerative capacity will overcome this, by regenerating newer muscles fiber lot faster than in normal human beings.
  2. Accumulation of metabolites: The Speedsters' enhanced metabolism will help them process & get rid of these waste products so that their muscles can be perfectly functional faster.
  • They also, rather obviously, run faster than normal human beings. Their regenerative capacity and enhanced metabolism would need to be proportionally better just to keep up and allow for such strain, but they could in theory still be tired after 20 minutes of their super run.
    – Deltharis
    Commented Feb 19, 2015 at 12:59
  • Not really... If that were the case you would see both The Flash & Quicksilver spending much of their time on a hospital bed & hooked up to 20 bags of Dextrose IV.
    – Stark07
    Commented Feb 19, 2015 at 13:52
  • @Deltharis - do you have any references to either of the speedsters getting worn out within 20minutes or so? Pretty sure time traveling will require a lot more than that.
    – Stark07
    Commented Feb 19, 2015 at 13:52
  • Hey, I don't think they do get tired. It's just that the argument presented in your answer doesn't prove that they don't.
    – Deltharis
    Commented Feb 19, 2015 at 13:55
  • @ash_k29 in the flip side, that enhanced metabolism means they will burn through their digested energy stores much more quickly and need to stop and refuel; it's not strictly what the OP is asking but the distinction between "too tired to move" and "too hungry to move" is pretty nitpicky.
    – KutuluMike
    Commented Feb 19, 2015 at 14:09

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.