Does running on a curved, non-motorised treadmill require more effort and musculature involvement than a traditional, motorised one?
Review by Dr Mike Climstein PhD & Dr Joe Walsh PhD
THE QUICK READ
- The non-motorised curved treadmill originated in Germany in the mid-1970s
This type of treadmill is proposed to facilitate a more natural running style
- Researchers investigated whether running on a non-motorised, curved treadmill required greater energy expenditure than running on a traditional motorised treadmill
- Heart rate, RPE and oxygen consumption were significantly higher on the non-motorised curved treadmill than on the traditional treadmill
- The study lends support to including non-motorised curved treadmills in running regimes for the purpose of variability
- Previous studies have found validity in the use of the non-motorised curved treadmill, but have urged caution on the part of competitive runners for whom the apparatus may impact running gait.
Title: Physiological and Perceptual demands of Running on a Curved nonmotorized treadmill at different grades
Authors: Dr’s Schoenmakers and colleagues, School of Sport, Rehabilitation and Exercise, University of Essex, United Kingdom
Introduction: Do I consider myself athletic (despite my advanced age)? Absolutely. I can still surf, skateboard, rollerblade, cycle (without training wheels), study and teach karate. I do balance board training, have a good jump rope regime and turn the stairs into a workout by running up them (and walking down), hopping up every third step with both legs, or hopping up every second step, alternating legs – all of which is good plyometric training for increasing kicking power. I believe that most athletic-type movements are easy for me to adapt to. Or so I thought.
I have my normal gym training regime (i.e. order of exercises) that I have followed for decades. Although I loathe aerobic exercises like treadmill running, I appreciate the benefits obtained from high intensity interval training, so it’s first on the to-do list at the gym every session. And being the ‘I fear change’ person that I am, I have a favourite treadmill that I run on. It’s adjacent to the wall so I don’t have someone on each side of me while I am training (which is becoming the new normal anyway due to COVID-19 regulations), it is out of direct sunlight so doesn’t heat up mid-day, and is covered by two industrial strength fans that provide perfect cooling without blowing the air directly on me. Yes, I am high maintenance.
Just recently, after a morning teaching at university (metabolic health this semester) I turn up to the gym and someone is on my treadmill! OK, I have to get through this workout as I have research to get on with and no time to muck around, I will do abs, core and stretch first. Twenty minutes or so later and I want to get onto my treadmill, and someone is still on it. But I’ve noticed a new treadmill, very different from all of the others as it’s not flat, is obviously curved and has no power on button. How can this be? No matter, I am a coordinated, can-do anything athletic beast… aren’t I?
Apparently not. I found the curved, non-motorised treadmill to be much harder than a conventional motorised one (at the same running speed), however the real wakeup was when my usual treadmill became available and I quickly stopped using the non-motorised curved one and jumped onto my trusty old friend. OMG, what was wrong with me? I found myself unable to function on the motorised treadmill. Time to hit the weights, get home and read up on this newfangled motor-less intruder into my comfortable domain. This leads us to the subject of this Research Review, the study by Dr Schoenmakers and his colleagues.
The curved, non-motorised treadmill has actually been around for quite some time, with its development originating in mid-1970s Germany. The premise of this type of treadmill is that it is proposed to facilitate a more natural running style in which the user is required to run on the balls of the feet. The movement involves a mix of gravity and friction and, since the foot strike is not perpendicular to the belt, it forces the belt to move due to the curved shape of the treadmill. It supposedly requires more work (i.e. musculature involvement/effort) to move the treadmill belt, compared to running at the same speed on a traditional, motorised treadmill. This type of treadmill is also challenging in that it allows the user to subconsciously change their pace with every step they take, whereas with traditional motorised treadmills the speed is constant. This claim of ‘more work’ is what Dr Schoenmakers and his colleagues investigated.
“This type of treadmill is proposed to facilitate a more natural running style in which the user is required to run on the balls of the feet”
Method: In this study, 10 physically active and fit males volunteered to run for six minutes on both a motorised treadmill and a non-motorised curved treadmill. Participants ran at 10.0 km/h on the non-motorised curved treadmill and also at 10.0 km/h at 1%, 4%, 6% and 8% grade on a motorised treadmill. All testing took place over five sessions. During each session, heart rate, Borg’s rating of perceived exertion (RPE, rated 6 to 20) and oxygen consumption (VO2 ml/kg/min) were measured.
Results: Unlike me, all participants had no difficulty running on both the motorised and non-motorised curved treadmill. As predicted, the heart rate, RPE and oxygen consumption were significantly higher on the non-motorised curved treadmill than on the traditional treadmill, with the following results recorded:
TABLE: Increases in ‘work’ on curved non-motorised treadmill compared to different grades on traditional treadmill
|Grade on traditional motorised treadmill||Increase in oxygen consumption on curved treadmill||Increase in heart rate on curved treadmill||Increase in RPE on curved treadmill|
When the runners were at 10.0 km/h and 8% grade on the motorised treadmill, the values for oxygen consumption, heart rate and RPE were near identical to running at 10.0 km/h on the non-motorised curved treadmill. In short, the greater the incline on the traditional motorised treadmill, the closer the energy expenditure got to that of the curved non-motorised version.
“Heart rate, RPE and oxygen consumption were significantly higher on the non-motorised curved treadmill than on the traditional treadmill”
The authors concluded that the non-motorised curved treadmill elicited higher oxygen consumption, heart rate and RPE at all of the inclines except for 8% which elicited a similar result to running level at the same speed (10.0 km/h) on the curved non-motorised treadmill. The authors attributed the higher values recorded on the non-motorised curved treadmill to its unsteadiness. The authors recommended the use of the non-motorised curved treadmill to complete alternative running training sessions and to emulate uphill training sessions.
Pros: This is a good, practical study which lends support to including non-motorised curved treadmills in your running regimes for the purpose of variability. Previous research by Edwards and colleagues (2017) support the findings of higher cardiorespiratory costs using a non-motorised curved treadmill. They found that when running for six minutes (females 9 to 15 km/h; males 10.5 to 16.5 km/h), heart rate, RPE and oxygen consumption were higher on the non-motorised curved treadmill as compared to a motorised treadmill. Interestingly, the researchers also found that lighter runners were required to work at a higher relative intensity due to having to overcome the treadmill belt resistance on the non-motorised curved apparatus.
However, for competitive runners, caution should be exercised. A study by Hatchett and colleagues (2018) investigated the effects on running on a curved treadmill with regard to running gait. These researchers found significant changes in running stride length, step length, increased stride angle and an increased imbalance score.
I found the curved treadmill output screen to be very good, in that it provided me with speed (km/h), watts, time and distance. Although my initial encounter with it shook me out of my comfort zone, I’m determined to give the curved treadmill another shot and plan to incorporate a couple of weeks of high intensity interval training on it into my regime. Let’s see if my fitness improves.
Cons: It would have been beneficial for the researchers to also have investigated the direct comparison at lower intensities, such as walking and power walking between a traditional motorised treadmill and the curved, non-motorised treadmill. It appears that, based on this study, a curved treadmill is similar in energy expenditure to running on a normal treadmill with an incline. It may be that the higher energy expenditure is also influenced by running on an unfamiliar surface and goes down slightly as the runner adapts to it. The biomechanics of running on a regular treadmill is different to those of running on normal ground or a running track. It should be remembered that curved, non-motorised treadmill running also has different biomechanical requirements (Hatchett et al., 2018) than normal running. Therefore, caution should be used in extensively using a curved or non-curved mechanised treadmill to train for sports performance, especially running performance.
- Hatchett, A., Armstrong, K., Parr, B., Crews, M., & Tant, C. (2018). The Effect of a Curved Non-Motorized Treadmill on Running Gait Length, Imbalance and Stride Angle. MDPI Sports. 6(3):58-67.
- Edwards, R., Tofari, P., Cormack, S., & Whyte, D. (2017). Non-motorized Treadmill Running is Associated with Higher Cardiometabolic Demands Compared with Overground and Motorized Treadmill Running. Frontiers in Physiology. 8(914):1-11.
Dr Mike Climstein, PhD FASMF FACSM FAAESS AEP
Dr Climstein is one of Australia’s leading Accredited Exercise Physiologists. He is a faculty member in Clinical Exercise Physiology, Sport & Exercise Science at Southern Cross University (Gold Coast). email@example.com
Dr Joe Walsh, PhD
Joe is an exercise science researcher. He has worked in a number of large international research teams with study findings presented around the world. In addition to working in the university sector, he is a director of Fitness Clinic Five Dock and Sport Science Institute. sportscienceinstitute.com