This is a love story. Originally, I used to snub the treadmill. I fretted about the incline I should set it at to “compensate” for the lack of balls I had because I was running inside. While it is true that treadmill running is different from road running, the difference is not as intense as my beginnner-runner-self believed. I have now learned that the treadmill is my friend. When it’s 10 degrees (before wind chill) and my face chaps from the wind the minute I step outside, a 1.5 hour run may not be advisable. But instead of skipping that run and beating myself up all day, I can put my butt in gear in the basement.
However, there are still differences in running outsides versus running on a treadmill. The changes in terrain and uneven footing you may experience outside is replaced by a smooth track. Because the treadmill is essentially a conveyor belt, your gait biomechanics are altered, putting less strain on your hamstrings. This is because you are keeping up with the tread and not propelling yourself forward as you would be running on a normal surface. Some people have successfully run marathons after having only trained indoors, but it is advised that you mix it up and slowly incorporate more outdoor runs into your schedule as race day arrives. This will make sure that your accessory muscles that help with stability on uneven streets and race routes are ready to go come race day. (You wouldn’t run a trail race without having tried training on a trail with similar rooty and rocky outcroppings, would you?) It will also prepare you for the elements of your outdoor race such as heat, wind, or rain. The impact and intensity of running on treadmills can also differ from that of running outside depending on the deck of your machine. However, in the end, some runs done on the treadmill won’t hurt your training significantly. If you’re more focused on building up the mental endurance for a distance you have conquered before, treadmill runs can definitely help. There is nothing that strengthens your mental willpower than saying yes, I will put in another mile, even if the rest of the people in this gym are staring at me for having been on here two hours already.
If you’re still concerned about what incline to use, Jenny Hadfield from RW explains treadmill inclines:
The incline of a hill is measured as a percentage and so are treadmills. When you increase the level on the incline on the treadmill it is based on percentage not a level. So if you raise the treadmill to 2, it means you are running at a 2% incline (not a level two). Most treadmills can increase incline from 0.5 to 12%. Research has shown that when you set the treadmill at a 1-2% incline, it will simulate the “intensity” of outdoor running (make up for the lack of wind resistance in outdoor running). You’ll often hear recommendations to run at a 2% incline if you run faster. While this is true, and it is important to train to specificity, I believe running at a constant 1-2% incline on the treadmill isn’t the best way to go. One, it’s a mental nightmare. Two, the hills on the half marathon course in Central Park will vary in length and incline. And C, it can really mess with your biomechanics if you aren’t used to running at a constant incline.
Some treadmills even come with a downhill option where you can apply a negative grade. Mine doesn’t. This is a helpful tutorial for making negative grades on your treadmill if you have one like mine. As always though, use caution when modifying your machine.
As Jenny says, incline training is good for burning more calories and mimicking the ups and downs of an outdoor course. The 1% incline myth that many of us have heard, that a 1% incline compensates for the wind resistance that you would experience running outside, is indeed a myth. Air resistance is minimal unless you are running at sprint speeds, negating the need for an obligatory incline during steady state runs:
Although over-ground running creates air resistance, such resistance brings an added aerobic demand only at velocities considerably faster than those routinely used in our evaluations. According to the studies of Pugh (1970), the effect of air resistance starts to increase O2 consumption measurably only at faster paces.
If you’re still not sold on the wonders of the treadmill, studies have shown that it is possible that treadmill running increases the muscular demands on your hip flexors and knee extensors, leading to an increased stride rate in equal road-distances.
Reporting in Medicine and Science in Sport and Exercise, researchers evaluated the kinematics and biomechanics of treadmill running and determined that running on a treadmill increases the muscular demands made on hip flexors and knee extensors. The authors concluded that treadmill running might improve sprint times due to the extra effort of those key muscles. Other studies have shown that the treadmill requires a higher stride frequency because the treadmill pushes the rear leg forward and the advancing leg must plant more quickly. As a result, a faster cadence and shorter stride produces more steps per mile and the cardiovascular demands of running may be higher on a treadmill than outdoors at the same pace.
In the end, I will always choose running outside rather than running on the treadmill. If the conditions are icy or dangerous outside (ie: thunderstorm) I’m not against hopping on the dreadmill, though. Now that I’ve moved my family’s from the oil tank room out in front of the den TV, running on it is a lot more enjoyable. It’s also a great way to get in some miles when you’re trying to bust the winter blues. :)
AND here are some treadmill workouts if you need inspiration: