Tell me if you’ve ever had this conversation with someone:

I can run 6 minute miles forever on a treadmill, but I can’t even come close to that on a track; it’s just so much easier to run on a treadmill, for some reason.

Your mile time aside, everyone knows that running on a treadmill is easier; but why is this? It boils down to a few factors, with the main factor as my main source of hatred for the wretched machines:

1. The treadmill paces you. You can’t slow down on a treadmill unless you adjust it’s speed. Thus, it decreases your natural inclination to slow when you tire.
2. There is no wind resistance. Air, innocuous as it may be, creates drag on your body as you run through it; This makes you run slower.
3. The toll on your muscles is altered by the sweeping motion of the treadmill belt. Because it propels your striking leg backward, instead of you propelling your body forward, your glutes, hamstrings, and posterior chain in general don’t have to work very hard.
4. You get to look at fitness hotties at they walk by (OK, that one is sort of made up, but it might motivate you to keep running hard)

Why Run?

It’s great for your heart, legs, body composition, and postural muscles. It becomes hard just to keep your body upright after logging a bunch of miles or sprints. Running is great, as long as it’s tailored to your goals.

What are Your Goals?

Chances are, you run to lose or maintain weight, increase athletic prowess, strengthen one’s heart, and tone up the leg muscles. Fair enough.

But, if you’re going to run to get better legs, you want to get your money’s worth. This is where the treadmill really sucks – because the treadmill does the work for your posterior chain (referring to the posterior muscles of the low back down to the hamstrings), you don’t tire as easily, and you don’t get much of a workout for your butt and hamstrings. Most, if not every woman, wants a more toned butt. If you’re running on the treadmill, guess what? You’re not going to get it.

This sprinter's leg drives backward into extension...

The posterior chain,(remember – butt, low back and hamstrings) assisted by the quads, is what works to propel your body forward while running. Sprinters have incredibly strong posterior chains, and some of the best functioning and looking legs on the planet. They put their feet to the pavement, not the treadmill.

See how the back leg is straight? That's where most of the work in running is done - driving that leg back and the body forward.

As you look at the above photo of Roger Bannister, the first man to break the 4:00 barrier, you can see two things at work: his left leg is extending by action of his strong posterior chain, thus propelling him forward, while the hip flexors in his swing (right) leg are bringing his knee up and into position to take the next stride. If you run on a treadmill, you basically forgo the leg drive that you would get on the earth, and turn running into a repetitive hip-flexor exercise. Hip flexors aren’t that sexy, and aren’t that important in making you a faster running or better athlete. Make your training mirror your goals – if you want better legs and improved athleticism, running on a treadmill is a waste of time.

You would run faster and longer on the moon, too

To summarize, the reason treadmills suck is that they take the load off of your posterior chain, thus making running easier and less beneficial for your body. Plus, if you do all of your training on a treadmill, then try to run a road race, you will be weak in all the most important places. It’s better to maximize your running time by simply doing it on the ground, without the assistance provided by the machine.

Everything in life is a trade off – if you want to make running easier, then you’re going to get less out of it as well. But if you’re dedicated to improving your body or athleticism, you need to start putting your feet down and push some real earth with each stride.