I have been discussing and researching this debate the past couple of days. To me, I think you have to run a "farther" distance on a treadmill to get the same workout you do on the road. But looking around online, there's not a lot of hard evidence to be found. Of course, no one at a gym who is trying to get you to pay them a monthly membership fee is going to tell you running on a road is better than running on their treadmill.
I did find this article. It's pretty good, if you have time to read it. Here are a lines I liked from the article:
"six-minute miling pace on a treadmill usually produces lower heart and oxygen consumption rates than same-pace running on the track..."
"There is little doubt that treadmill training is better for fitness than a completely sedentary lifestyle, and there is no question that non-competitive joggers can improve their overall fitness on a treadmill..."
To me, the #1 thing you cannot account for on a treadmill is wind resistance. You can't overstate how important that is, or maybe I should say, how big a difference that makes. From experience, even a light wind makes a big difference if you're running into it.
#2 is the shock and jarring that your body takes on the road. Treadmill running is definitely gentler, and better for your knees, I'm sure.
I just think if you were to run two miles on a treadmill today, and two miles on the road tomorrow, you would definitely feel it more from the road. And those are the main two reasons, in my opinion. It seems like you get a lot more out of breath on the road as well.
Also, on the treadmill, there's really no propelling yourself forward. It is running and all you're doing is stepping, basically. While your grounded foot is on the mill, you lose something, because the mill moves it for you, if that makes sense.
There are two advantages to running on the road, that might make it seem a little easier than the mill. First of all, the change of scenery probably keeps it from being as boring. Secondly, you don't have the natural cooling of the air hitting your body in a gym. Of course, if you're watching TV in a well air-conditioned gym, then those points are no good. lol
Of course, the treadmill has advantages. Besides being a lot less jarring to the body, you don't have to worry about weather. And, you can keep a steady pace. It's sometimes difficult to stay at the same speed on the road.
Lastly, I'm not really sure how accurately a computer can measure distance. I remember we used to have a stationary bike when I lived at home, and I could knock out five miles on that thing in no time. Speaking of, I need to tune up my bike and start riding again.
So, road or treadmill? Well, I'd say whichever works best for you. The main thing from a fitness standpoint is increasing the heart rate and burning calories, right? But I would say to try out both. And don't fool yourself into thinking that just because you knock out three miles on the mill, that it's going to be that easy on the pavement. And if you're training for distance running, I'd say definitely take the road most of the time. However, I think the mill could be used to supplement road training, on rainy days, and also to help pace yourself. Oh well. I hope you enjoyed today's discussion. And keep in mind, all this comes from a road runner. Beep beep. ROFL Oh man, that was the corniest thing I've ever said. I should really delete that. I really should.
"It always seemed such a waste. She always had a pretty face. I wondered why she hung around this place..."