This week was better hitting the 20 mile target with good runs out on the road. Each week im just about making the target of 20+ miles a week i set for myself when i started to plan for next year. I'm aiming to keep this up until December. Then after new year the miles will increase, incrementally as I get closer to the 100 in July, with futher recces and events inbetween.
This mileage might seem low to some, but it is the mileage I ran earlier this year to prepare for the Calderdale Hike, The Wall Run and Lakeland 50, all of which I improved on more than I expected. Also through a bit of luck (im now seeing it as this) my circumstances at home dont allow me time to overtrain, hence the reason (touch wood) i rarely get injured. This has been and will continue to be a steady progression for me into the ultrarunning world and hopefully i can remain injury free.
This is the question i need to answer, below are parts of a study summarised on a site asking a similar question.
Stride Length and Rate
A study by Elliot, B.C., Blanksby, B.A. Medicine and Science in Sports looked at these two factors.
No significant differences were recorded in stride length, stride rate, support time or non-support time on a treadmill compare to outdoors for men or women when jogging at velocities of between 3.3 and 4.8 m/s.
As speeds of running increased over 4.8 m/s on a treadmill compared to outdoors: stride length decreased, stride rate increased, and the length of time the support leg is on the ground increased.
So at these higher speeds you are taking shorter strides and getting longer ‘rest’ time each time one of your legs is on the ground. This is countered however by an increased number of strides per minute.
Propelling Your Body
This is the kicker here. The main difference between treadmill running and outdoor running lies in how your legs have to carry your upper body.
Outdoor running, your leg muscles mostly work on propelling you forward. Treadmill running, because the belt is moving under you, your leg muscles mostly work at re-positioning your legs to keep you stable.
This affects how much work your individual leg muscles need to do.
Treadmill running, the rearward moving belt decreases the need to pull your upper body forward and so requires less work from your hamstrings than outdoor running. However, your hip flexors (right at the top-front of each leg) have to work harder to provide stability as your planted foot is dragged back (literally) under your body.
(Source: Dave Schmitz PT, LAT, CSCS, PES Health Services at Columbia)
So in treadmill running we have a situation where the hamstrings are less-used and the hip flexors are more used than when outdoor running. This will have an influence on energy output. Hamstrings are b-i-g muscles in the overall scheme of your body – in fact, they are your biggest of all muscles. They use up a lot of energy to expand and contract during each stride. Hip flexors are much smaller and so would intuitively require less energy to squeeze in and out.
Studies estimate that the energy expenditure required by your leg muscles is 3% greater for outdoor running over treadmill running (running at 4.0 m/s).
We use our legs in different ways on a treadmill.
Total Energy Difference
Combine this with our knowledge that overcoming wind resistance outdoor running requires a 5% increased effort (at 4.0 m/s)
And the end result is running at 4.0 m/s you can expect to be working somewhere around 8% harder outdoor running than treadmill running.
So how can you make treadmill running require the same level of energy use as outdoor running?
A 1996 study in the Journal of Sports Science – taking into account the above factors – concluded that a 1% treadmill grade most accurately reflects the energetic cost of outdoor running.
So if you want to match the energy required outdoor running, put your treadmill on a 1% incline.
Other Factors
Aside from energy expended, there is one important factor that makes treadmill running easier than outdoor running:
The treadmill surface is always softer than a hard sidewalk or road surface. That makes it a whole lot easier on all your joints, and without joint pain you can run for longer and be much happier about doing it.
Let’s see. If you set your treadmill to a 1% incline you’re going to get the benefits of the same energy output (and so calories burnt) as outdoor running, plus your joints will be much better protected.
The Mental Challenge
There is one aspect, not related to energy requirements, that effects how easy your run will be.
As I see it, being distracted when running makes things a whole lot easier. Distractions include listening to music or watching tv while you workout. When you focus on something else rather than your body, you don’t notice your body so much. This helps to alleviate any running discomfort. This is why running with someone or in a group is much easier than running by yourself. There is no better way to distract you from what you are doing than my conversing with someone.
Listening to music distracts from effort
But focusing on external distractions can also take away from the actual intensity that you can go to and the overall exertion that you feel. And sometimes (most of the time) actually feeling that effort and intensity is a large part of the fun. Like for my daily 1 km time-trials (which I’ve been experimenting with since the motorway run) I run without my ipod so I can focus exactly on the level of exertion on my body.
To wrap this all up, we can say that treadmill running with distraction (people, tv, music) is going to feel easiest and require slightly less energy. Outdoor running with no music is going to feel hardest, but you will benefit from expending more energy (and likely burning more calories).
So basically the above and other studies are saying it is much easier to run faster on a treadmill than outside as you are assisted by the belt. I'm of the complete opposite view. I run faster when outside. I think this is more of a mental thing, it's miles better to run outside, wind in your face, inspiring scenery and so on. For a 10k for example I can't get anywhere near the 41.01 time (my pb for that distance) on a treadmill . I put this down to mental fatigue opposed to physical. As however far I run on the treadmill during the week it's nothing like getting out on the road or trail. It's basically a means to an end, ensuring I get some miles in during the week in addition to at least 1 long run at weekend.
If its a chore to run then and you don't enjoy it and are just doing it for the end result then I guess you will need the distractions to get through the run mentally. I'd much rather run outside with no music, I think the difference here is that the perhaps author is thinking that the runners are running even though they may not want to and dont enjoy it. It's far better running with no distractions, the rhythm of your feet striking the ground is enough for me, getting lost in my own thoughts and before I know it miles and miles have passed.
With the above brief study it makes a point that the biomechanics are different when running on the road than on a treadmill, and that when on the road you are using all your energy to propel yourself forward. This goes against what I have read elsewhere in part, regarding technique and form for efficient running. I don't run barefoot but the technique is sound, leaning slightly forward at the ankles, not the waist and keeping strides short and under you, and contact with the ground to a minimum. The foot should strike ball of foot first, and not the heel. The heel strike sends unecessary force to parts of your legs, back and upper body that dont want and arent effecient at disperisng said forces. The forefoot or midfoot strike should be directly under your centre of gravity The leaning forward allows you to be almost gravity assisted, with the lifting and replacement of the legs keeping you from falling forwards which can also be described as running.
Stu Mittleman, a member of the USA ultrarunning hall of fame is a treadmill advocate, see the link below for a correct use of a treadmill video.
http://marathonmastery.com/treadmill-training/ <http://marathonmastery.com/treadmill-training/>
So my thoughts are now that as long as good form is maintained when on the treadmill, and i get out at weekends either on the trails or road there doesnt seem to be any great problems running on a treadmill, plus it also keeps my weekly mileage to the level i need to be doing for next years events.
