Power Profiling & Bike Movement: Suffering for Science
On April 28, 2020 Zwift and their eSports verification group, the Zwift Accuracy and Data Analysis (ZADA), rolled out a significant update to their Cycling eSports Rules & Regulations. The update included a requirement that all riders wanting to participate in their Pro-Am Invitational races must provide power profiles for best 10+ minute, 5 minute, 1 minute, and 5 second power efforts outdoors. The rider must also complete a route on Zwift featuring climbs of similar duration while recording live on video. The latter requirement is known as the “Three Sisters Test” for its use of Watopia’s Three Sisters route.
This sounds complex, but for teams like ours, we were well-prepared and truly welcomed the additional steps towards registration for Zwift’s invitation-only events. Requiring these items before races will foster fairer racing, which will be better for both racers and viewers alike! As we set out to prepare for these tests, we thought it would be interesting to compare the outdoor and indoor efforts, and determine whether or not using a rocker plate would help bridge the gap between power production outdoors versus riding with your smart trainer set on the ground.
The Tests
First things first, performing the Three Sisters Test to get ready to register for Zwift’s Pro-Am circuit. The key steps which riders are required to record on video are: a warmup, calibration of trainer and offset of secondary power meter, then the rider is required to complete Watopia’s Three Sisters route. During the ride on this route, riders are required to perform their best efforts on the three timed climbs, and finish the ride with a fifteen-second maximum power sprint.
The three climbs are as follows: Hilly Forward KOM (~1:30 duration), Epic KOM (~19:00 duration), and Volcano KOM (~6:00 duration). The result is a power profile exhibiting a riders ability across a range of efforts, and demonstrating their secondary power source and trainer’s accuracy. As we looked at this test, we knew taking the same format outside, and then redoing on the Saris MP1 would yield an interesting dataset.
The tests laid before our faithful guniea pig, Matt Gardiner:
Three Sisters Test with smart trainer on the ground
Three Sisters Test with smart trainer on the Saris MP1
Three Sisters Test while riding outdoors.
The question we hoped to answer: does bike movement have a significant impact on power output?
Smart Trainer on Ground
First up, Matt went with what he knows best: riding on an unmoving, solid surface. Recording these efforts to submit for his own verification to ZADA, Matt tapered into the test, knowing his future performances in Zwift’s Pro-Am circuit would be measured against it.
With the course set for Zwift’s Three Sisters route on Watopia, Matt invited all 12 of his teammates to a meetup at 4:45 AM on a Saturday—who wouldn’t want to suffer for 90 minutes performing personal best power output for four key durations?! Surprisingly, his teammates agreed, set up their own cameras and power meters, and showed up on time. The meetup began and the team set out to crush the Three Sisters route together. Over the course of 90 minutes, Matt put down the efforts as follows:
Hilly Forward KOM: Duration: 1:28, Power: 586W
Epic KOM: Duration: 19:00, Power: 361W
Volcano KOM: Duration: 5:54, Power: 443W
Sprint: Duration: 0:05, Power: 956W
With the team all pushing each other on the climbs, the motivation ride as hard as possible was huge. At the end of the ride, a massive weight was lifted having completed the hardest piece of the ZADA verification puzzle. Matt loaded the video to YouTube, downloaded the files, and sent it off to vouch for his abilities on the bike and his power meter’s accuracy! All that laid ahead was data gathering for the sake of data gathering. He planned for the next weekend to meet up with teammate and STPC co-founder Matt Brandt and go crush some climbs together!
Outdoors
The week flew by, and the second day of testing, which is also a requirement of the Cycling eSports Rules & Regulations, finally came. The plan for the ride was to gather outdoor data on gradients exceeding 5%. This requirement enables the recalculation of speeds at a given power-to-weight (Watts-per-kilogram). Living in Iowa, Matt has almost no access to climbs, so he met up with Brandt, loaded up the Saris EX-Superclamp rack with their new bikes from The Pro’s Closet, and setting off for Blue Mounds, Wisconsin which is a state park featuring plenty of steep and scenic climbs.
The duo set their sights on a few climbs which fit the criteria for ZADA’s outdoor efforts:
A ~90 second climb: Pinnacle Road Climb
A ~5 minute climb: Baseball Field to Top
A ~14 minute climb: Mounds Park Road Climb
While nabbing some KOMs is always a goal outside, these roads were the USA Nationals Road Race for many years, and have had massive pelotons storming the climbs to finish races. The chance that the pair would contend with the times on the Strava leaderboard were slim, but they weren’t going to let that stop them!
They began the ride heading out to the Pinnacle Road Climb. Knowing they just needed 90 seconds to compare to our prior Static Test, they didn’t contest the entire 2:30 KOM. Hitting the base of the climb, they lapped their Garmin’s and went to work for 90 brutal seconds. The result: 616W — a full 30W more than he’d produced just 6 days prior. Upper body draped over the bars, standing mid-climb 5 miles from the next effort, Matt knew he was in for a lot more pain.
They descended back towards the next KOM: Mounds Park Road Climb. The ascent from the North side of the park to the peak is an undulating road which averages 5%, but features steep pitches up to 13%. They hit the climb and set off at a steady, hard effort. Working to motivate each other by taking turns on the front to keep the pace high. After 8 minutes, Matt looked down and saw he had been averaging 415W, punching well above his abilities. Wheezing aloud to Brandt, “I’m—wheeze—over pace”, which Brandt replied between exasperated gasps, “me too.”
Matt hit the last rolling descent on the climb averaging 390W after coasting into the turn towards the final climb—a 3:30 effort at 10% gradient. Working against the constant resistance of the climb, he averaged 420W up the final pitch, putting his average for the 13:31 climb at 400W. While the effort was 5:29 shorter in duration than the Static Test’s Epic KOM, the power was a significant 39W higher.
All that remained for the day was two efforts: a 5 minute climb and a maximum power sprint! The Matt’s descended through the park in order to come back up the steepest side; a sustained 5-minute grind at 8% gradient. They hit the start and got to work, with the previous efforts still lingering in their legs. Matt crested the top of the ascent, looking down at his Garmin to see an average of 459W for 4:52. While a full minute shorter than the Three Sisters test, he produced a significant 16W more.
Rolling around the top of the park at an easy pace, catching his breath and relieved to have the difficult efforts completed, all that remained for the day was to hit peak power for a refreshingly brief 5 seconds before packing up the bikes and making the 5 hour drive home! The pair started down the descent to the first flat section, turning back towards the climb and accelerating with everything they had—lurching forward, Matt hit a maximum wattage of 1,128W and sustaining 1,064W for 0:05, besting his previous test by a massive 108W!
Relieved to having the efforts in the bank, they rode back up to the car, hit “save” on their Garmins, and waited for the data to sync to Strava and TrainingPeaks. Once it appeared to be backed up, they loaded up the car and started the journey home!
Smart Trainer on Saris MP1
Having spent the weekend recovering from the outdoor testing, Matt set his sights on finishing the testing as soon as possible in order to be in the same form as the other efforts. He set up his Saris H3 trainer strapped onto the MP1 and gave the test one last go. Having completed the outdoor effort just 4 days prior, and the initial test 6 days before that, he was no stranger to what laid ahead: pain and suffering.
On this final virtual adventure on the Three Sisters course, teammates Chris Beck and Matt Brandt joined for the fun. The three pushed each other, dropped each other and Matt and Beck both begged Brandt to go easier multiple times. On the MP1, Matt put down the following efforts:
Hilly Forward KOM: Duration: 1:28, Power: 597W (+11W over Test #1)
Epic KOM: Duration: 19:00, Power: 366W (+5W over Test #1)
Volcano KOM: Duration: 5:00, Power: 434W (-9W over Test #1)
Sprint: Duration: 0:05, Power: 998W (+42W over Test #1)
With Beck and the Matt’s pushing each other on each climb, the efforts were truly to exhaustion. Without question, Matt began the day under a great deal of fatigue, which showed clearly on Volcano, where he cut the climb short once he had hit the 5 minute mark. However, a few key takeaways became clear during the final test.
The Data & Key Takeaways
Having gone through all the tests in a relatively short window, while there may have been lingering fatigue in the efforts, Matt’s form was nearly the same from test to test. Here’s what we learned:
Matt’s power outside exceeds his indoor efforts
Bike movement = more power
The MP1 actually improved indoor power production
Power profile testing is hard. Like really hard.
On the one case where the MP1 power production fell short was the Volcano (VO2max) on the Three Sisters Test. Given the test was last in a 10-day window of testing, Matt’s fatigue level was a bit too much to sustain a high-quality VO2max interval. The trend displayed by the other efforts (0:05, 1:30, 14:00, and 19:00) shows that the MP1 allows for riders to generate more power by moving the bike more closely to how you would outdoors.
Check out all the charts:
The final two graphs (14:00 and 19:00) will stand out for a few reasons. The 14:00 climb is included because that is the duration of the longest outdoor effort (13:31 actual duration). On the Three Sisters Test indoors, this is comparable to the Epic KOM climb from the base to the exit of the tunnel just before the first mid-climb descent and rollers. The 19:00 climb excludes outdoor power numbers because there just is not any climb that long in the Midwest United States.
How do your indoor and outdoor efforts compare? Does bike movement make a difference for your power production? Let us know in the comments!