Mind-blowing footage shows Michael Phelps swimming compared to an average person

Watching the Olympics is always very impressive, but sometimes it's possible to get a false impression of the level of the athletes.

See, when you have the best athletes in the world for any given sport all lined up to compete, it can give an inaccurate impression that they're somehow average, instead of world-class.

Luckily, there is a very easy way to break this illusion.

That is of course to pit one of these super-humans against against a hapless victim.

Sorry, I mean, 'average person'.

And that's just what one video did between swimmer Michael Phelps and an average swimmer.

Now, I'm sure you don't need me to tell you that Phelps is something of an icon.

But there's good reason for that.

The swimmer has a vast wingspan, meaning his arm strokes are more powerful, and double-jointed ankles which give his kicks greater range.

Not only that, but his body reportedly produces half the lactic acid of a regular athlete.

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Lactic acid is the chemical which makes your muscles ache when you exercise. Less of this effectively means that Phelps' muscles don't fatigue as quickly, so he can maintain his top speed for longer.

Even by Olympian standards, Phelps is extraordinary.

One video shows the man who has been called 'the greatest swimmer of all time', going up against a regular swimmer.

The challenger begins their swim in a small pool, while Phelps walks in the waist-deep water observing them.

And by all accounts, the challenger seems like a perfectly okay swimmer that you would see at your local pool.

Then, Phelps takes to the water, and the difference becomes immediately apparent.

The first thing you notice is just how calm the Olympian is in the water. While the other swimmer thrashes in the water and makes quick strokes, Phelps' strokes are long and slow, and the momentum of each one carries him much further.

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But the moment which really shows up the difference is when they go head to head.

Competitive swimmers use a technique called the 'dolphin kick' at the start of some races. This is where you undulate your lower body so that your feet act as a single 'fin'.

It's tricky to master, as it requires good lower body strength and flexibility in your leg and ankle joints to use effectively.

While the average swimmer begins front crawl very early, Phelps is already halfway down the pool before he even starts the main stroke.

So, just in case it wasn't clear just how extraordinary Michael Phelps is, this makes it abundantly clear.

Perhaps every Olympic event should have an average person competing, just to reinforce that even the people at the bottom of the table are incredible athletes.