While logging miles over the next few months – you will have the option of lacing up and heading outside or gearing up inside to hop on the treadmill. I get asked about the difference between running on a treadmill versus outside on the regular – so today we dive into some science to see exactly what the difference is!
The number one concern is mechanics! Does someone change the way they run? This has been heavily debated for decades and we have seen a shift in data as technology has improved and treadmills have evolved. The most recent research shows very small changes in running mechanics when comparing treadmill running to outdoor running. There is some research that demonstrates a shorter stride length and increased cadence with treadmill running but this is sometimes caused by hovering too close to the console or holding on. If using a treadmill, be sure to use proper form. The mechanical belt of the treadmill does assist with indoor running because it brings the supporting leg back under the body (hip extension) during the support phase while outside you would have to propel yourself forward.
Overall, keep in mind that treadmill running tends to be identical repetitions of the same kinematics while outdoor running involves regular changes in surface, direction, pace, and stride length. Even though no scientifically significant differences present, the experience is not the same.
Is there a difference in the injury risk? This is very interesting because the softer surface of the treadmill results in reduced forces on the muscles and bones – but will also result in a reduction in bone strengthening as compared to outdoor running. This is an important note if you do all of your training runs indoors – and then run a half marathon on the pavement. It is important to note that treadmill and outdoor running both help improve bone strength compared to exercises like the elliptical and bike.
The most important factor when it comes to risk of injury and running whether it be indoors or outdoors is an appropriate strengthen training program. Incorporating a strength training program will help improve your alignment, strengthen your muscles in all three planes of motion (essential!), and help absorb the forces while running.
Is one harder than the other? At identical speeds, running on the treadmill has a decreased energy cost as compared to outdoor running. This can be attributed to lack of wind resistance, consistent terrain, and the movement of the mechanical belt. When running indoors, the environmental conditions remain the same and there is no wind resistance or changes in terrain that require the body to utilize more energy. You can provide some variety by changing up the incline on the treadmill to increase the metabolic cost of the exercise.
So what should you do if you are training for a race? Training for a race is a lot like studying for an exam – you want to practice what you are going to face on test day! Your race is going to take place out on the road and you need to prepare your body for anything that will arise on race day. This includes inclement weather, fueling plans, pacing strategies, and the physical demands of pounding the pavement.
The weather will always be unpredictable and the only way to be ready is to run in all conditions (that are safe ofcourse- I recommend skipping any lightening or ice!). You not only learn how to mentally prepare but you also learn what clothing is appropriate for the various conditions. There is also something empowering about being out on the road when everyone else is taking cover.
Fuel and hydration plans vary depending on the distance and person but you need to know what works for you. The best way to calculate your needs is my replicating your race day and monitoring the way you feel. Make adjustments. Retest. This is how the best runners master their fuel plans.
The biggest reason why you need to hit the road is for pacing purposes. Pacing is a fundamental skill that is critical for all runners to practice. It’s easy to “set and forget” on the treadmill but you never learn how to listen to your body and evaluate the effort of the pace. We’ve become overly dependent on mph and splits instead of our breathing, stride, and exertion.
And as a bonus, you get a little dose of Vitamin D!
Is there a difference on my endurance between the two? Most people I interact with find running on the treadmill to be mentally exhausting. The treadmill didn’t get its nicknames “dreadmill” and the “human hamster wheel” from nowhere. When you run outside there are typically changes in scenery, changes in direction, and a sense of exploration. You lose that when you take it indoors and complete your workout by running in place. More times than not you end up checking the clock for what feels like 10 minutes but in reality it’s been 30 seconds. If you do have to complete a treadmill workout – I would recommend performing an interval workout or find your favorite tv show to help the time pass!
Cardiovascular endurance will benefit from both indoor and outdoor workouts. Sometimes a treadmill workout is the best option whether it be for convenience, safety, timing, or maybe you like to zone out and that’s okay! You will still reap the countless health benefits from your aerobic workout.
The take home message – if you are training for an outdoor race it is essential that you hit the pavement as part of your training. However, the treadmill can provide great adaptations as well if you are tight on time or it fits your schedule better. If you are running on the treadmill – be sure to not hover over the console and play with changing the incline to give you some additional resistance. But most importantly – have fun!