Treadmill is easier - it does half the work for you. I like it if i'm feeling lazy or sore, cause i can just turn it off and be done if something starts hurting. But outside is definitely the better workout so i guess that's the preferred choice. The boredom isn't an issue to me. I just turn on my ipod and zone out on a treadmill.
Roadwork is higher impact and will toughen up your shins and leg muscles more, on the other hand it can cause injury. Wind and drag also make a difference when running outside. Also it's true that you are propelling yourself forward more, so you're contracting different muscles. I have a sore ankle sometimes and have to hit the treadmill, if you use a 2% incline it's meant to replicate the intensity of road-running more accurately. The bio-mechanics of running slightly uphill is different though, so I wouldn't solely rely on a teadmill if I were you.
I prefer to run outdoors. I find running on a treadmill mind numbingly boring and not as challenging as running outside. I am lucky that I live near the beach so can run along the promenade with great views and 2 laps of my nearest park is almost exactly a mile so find it easy to keep a set pace by using the park.
I have went back to the treadmill.... for now. Until I get my running up and then I will go back to outside. When I stopped running for a while and went straight to running on the sidewalk I was getting shin pain and minor shin splints and could only run like once a week or less. But I remember prior to that last time I was running like 2 to 3 times a week fine and I first started on the treadmill then moved outside and didnt have shin problems. So I think I will start on the threadmill for a bit because that doesnt bother my shins then go back to running in the park.
Running on the road is much harder. On a treadmill you should set the gradiant to 1 or 1.5 or you're basically running "down hill". Even then it's still easier. Running on the road will give you more benefit, but will be higher impact and give you a higher risk of injury. The treadmill can be used as rehab if you have niggling strains. Both have pro's and cons, but assuming you're healthy the road is best.
Im starting my Amateaur career back after not training for nearly 4 years,and I have to start on the treadmill.I weigh 270 pounds.Treadmill is good for when you are out of shape.Now if I run outside I have less stamina because my kness and legs start hurting.Roadwork is by far harder and has more benefit.I remember Emanuel Steaward saying that Jermaine Taylor did a lot of treadmill running for his 1st fight with Kelly Pavlik(he said this in the pre-fight conversation on the Taylor-Pavlik 2 PPV)rather than go running outside with their group and he cited that as a reason for his underperformance.
No,I have fought at 178 and at crusierweight(well yes its called heavyweight in the amatears) I dont want to fight as a super heavyweight becasuse its just not an in shape weight for me.Im quicker and have way more power and stamaina at LHW
Outdoors, with the treadmill I keep looking at the time and getting bored. While outside time seems to fly.
i prefer outdoors. like some people have already said, i feel like the treadmill does alot of the work for you. if youre tired you can always put your legs on the sides, let the belt run, and still get "6" miles out the way. Real road work wil mean that you will have to run a certain amount of time or distance and if youre tired, your ass is still gonna have to walk or run back! so i think mentally and physically actual roadwork is tougher