Some three years ago, I approached two of the professors at the University of Nebraska Omaha (UNO) about conducting the first American study - at least to my knowledge - of the physiological effects of riding an electric-assist bicycle compared to a standard bicycle.
Intuitively, you would expect that there would be less physical fitness benefit to riding a bicycle that is partially propelled by an electric motor than riding one without a motor, in other words a standard manual bicycle. In that assumption, you would be wrong.
That's the preliminary findings of a study just now wrapping up as part of Taylor La Salle's master's thesis for the Exercise Physiology program at UNO. Fifteen student volunteers, (8 males, 7 females), two Currie Technology iZip Path electric bicycles, and many kilometers later, we now have confirmation of what other studies in Australia and Europe earlier demonstrated: you do get exercise riding an eBike.
How much? A lot more than Taylor La Salle or his professors, Drs. Berg and Slivak imagined.
While he is still wrapping up his research and preparing to defend his thesis in a month or so, La Salle participated in a University poster session today at the campus library, along with dozens of other graduate and undergraduate students on a myriad of different topics. The title of his poster is "Physiological demands riding an electric assist bicycle." Since I was responsible for arranging Currie to donate the two eBikes, I was keenly interested to see what his research uncovered.
Standing next to his poster, one of the bikes parked in front of him, La Salle explained to me the protocols for his tests. The first one was the decision to use the same bike for both the electric and non-electric segments of the course. The test rides were conducted outside using a route of city streets that wound east of the campus, one portion of which included a long, uphill climb from Happy Hollow Blvd up Harney Street to around 52nd St.. The distance the volunteers rode - twice - is 3.5 km in length. The average time to complete each ride, one using pedal assist, the second without assist, but on the same bicycle, took about 12-minutes.
The bike was instrumented with a Garmin GPS that also collected heart rate. Both pedals are fitted with strain gauges to measure torque and cadence. Each rider wore a device to capture heart rate and a mask to record oxygen intake.
La Salle explained that he chose the 3.5 km course in part because the American College of Sports Medicine (ACSM) recommends brief, 15-minute, daily workouts to stay fit : the more the better. La Salle reckoned that someone commuting to work riding 3.5 km or thereabout every day would get two workouts, one in the morning, one returning home in the evening.
After collecting, tabulating and analyzing the data, La Salle reached three key conclusions:
(1) The actual amount of energy expended by the riders was nearly identical for both modes: electric-assist and manual.
(2) The biggest difference was in the time it took to complete the circuit; on average riding the eBike took around 1 minute less than in the non-electric mode.
(3) Significantly, all the riders rated their perceived exertion (RPE) using the ACSM's scale as being easier using electric mode made. If riding the bike in manual mode was rated 15, riding it in pedal-assist mode was a 10. That's a huge difference in rider perception between the two modes.
So, in effect, as a group, they completed the course sooner, felt better at the end, and yet burned virtually the same amount of energy.
That no one expected.
La Salle recognizes that having the volunteers riding the same admittedly heavy bicycle (the test bikes both weigh over 50 lbs.) for both runs, rather than allowing them to use a lighter road bike, might have some affect the results of the study. It was a decision he feels makes sense, especially since most bikeshare bicycles, for example, are comparably heavy. There is a B-cycle bikeshare dock on campus not that far from the Library.
La Salle plans to include one more female volunteer to make it 8 men and 8 women in the study. He will finish his thesis and then look for the right journal in which to publish his findings. After that, he is looking for a place to make use of his knowledge.
I wish to personally thank, Taylor, Drs. Berg and Slivka, the University, and Larry Pizzi at Currie Technologies for helping make this study happen. It took time to get here, but the outcome has been well worth waiting for.
Posted By: Bill Moore [06-Mar-2015]
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