Trying to understand Wattbike plot
rumbataz
Posts: 796
I've rejoined my old gym this week and tried out one of their new Wattbike machines. I was told to try and achieve a horizontal figure of 8 on the display. However, the left part of the 8 was lower than the middle marker. The right part was actually not bad.
So there's obviously something I'm not doing right in my pedal stroke with my left leg.
Anyone familiar with Wattbike gym equipment who can shed some light on how I 'fix' my left-leg pedal stroke?
So there's obviously something I'm not doing right in my pedal stroke with my left leg.
Anyone familiar with Wattbike gym equipment who can shed some light on how I 'fix' my left-leg pedal stroke?
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Yep. Don't worry about it. It just means one leg is slightly stronger than the other. Like it is with nearly everyone.Insta: ATEnduranceCoaching
ABCC Cycling Coach0 -
I don't think Wattbike can actually measure left/right power independently anyway, so any plot it gives you won't mean much, if anything.
Either way, as NapD says, a power imbalance is perfectly normal.0 -
Okay, thanks all.0
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Download the Wattbike guide from their site - it gives a good summary of the pedal graphs.All the gear, but no idea...0
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You are after a sausage not a figure of 8. For some reason a lot of PTs are telling clients to aim for a figure of 8. The better informed say a peanut. But Wattbike clearly shows this is not the goal.
https://wattbike.com/uk/guide/cycling_tests/pedalling_technique_test/what_the_polar_view_shapes_mean
They are fun things to play on and can at least be accurately set up unlike a typical spin bike.0 -
My apologies, the PT did mention trying to get a peanut display. Once on the bike I forgot what he had told me and decided to try for a horizontal figure of 8. Regardless, the left hand side was lower not matter what I tried.0
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That article is belief based nonsense.You are after a sausage not a figure of 8. For some reason a lot of PTs are telling clients to aim for a figure of 8. The better informed say a peanut. But Wattbike clearly shows this is not the goal.
https://wattbike.com/uk/guide/cycling_tests/pedalling_technique_test/what_the_polar_view_shapes_mean
They are fun things to play on and can at least be accurately set up unlike a typical spin bike.0 -
[url=http://www.bikeradar.com/forums/viewtopic.php?p=19715169#p19715169]Alex_Simmons/RST[/url] wrote:
That article is belief based nonsense.You are after a sausage not a figure of 8. For some reason a lot of PTs are telling clients to aim for a figure of 8. The better informed say a peanut. But Wattbike clearly shows this is not the goal.
https://wattbike.com/uk/guide/cycling_tests/pedalling_technique_test/what_the_polar_view_shapes_mean
They are fun things to play on and can at least be accurately set up unlike a typical spin bike.
Alex - are you able to expand on this comment please - I am genuinely interested
Cheers
Martin0 -
There is a school of thought that says the wattbike polar view is unproven as a cycling aid:
viewtopic.php?f=40011&t=12964858#p188164450 -
Yeah, I'd be interested too as I'm planning to use the Watt bike over the winter.[url=http://www.bikeradar.com/forums/viewtopic.php?p=19715169#p19715169]Alex_Simmons/RST[/url] wrote:
That article is belief based nonsense.You are after a sausage not a figure of 8. For some reason a lot of PTs are telling clients to aim for a figure of 8. The better informed say a peanut. But Wattbike clearly shows this is not the goal.
https://wattbike.com/uk/guide/cycling_tests/pedalling_technique_test/what_the_polar_view_shapes_mean
They are fun things to play on and can at least be accurately set up unlike a typical spin bike.
Alex - are you able to expand on this comment please - I am genuinely interested
Cheers
Martin
My understanding is that the bike was designed along with British Cycling, so I'd expect them to know their stuff.A fanatic is one who can’t change his mind and won’t change the subject - Churchill0 -
If the Wattbike gave a truly independent left/right leg plot, if you took your left foot off the pedal (for instance) you would expect the left reading to drop to zero. Give it a try...0
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Yeah, I'd be interested too as I'm planning to use the Watt bike over the winter.[url=http://www.bikeradar.com/forums/viewtopic.php?p=19715169#p19715169]Alex_Simmons/RST[/url] wrote:
That article is belief based nonsense.You are after a sausage not a figure of 8. For some reason a lot of PTs are telling clients to aim for a figure of 8. The better informed say a peanut. But Wattbike clearly shows this is not the goal.
https://wattbike.com/uk/guide/cycling_tests/pedalling_technique_test/what_the_polar_view_shapes_mean
They are fun things to play on and can at least be accurately set up unlike a typical spin bike.
Alex - are you able to expand on this comment please - I am genuinely interested
Cheers
Martin
My understanding is that the bike was designed along with British Cycling, so I'd expect them to know their stuff.
I'm not Alex (!) and i'm sure when he has time he'll write a better reply
, but simply
1) the Wattbike doesn't measure power from each leg independently, so any plots it comes up with are bunkum, and,
2) there is no evidence that people should be pedalling in any specific way other than that which allows them to generate the highest power over the duration(s) they're interested in. The only decent evidence on pedalling shows that better cyclists stomp down more and pull up less than less good cyclists
RicCoach to Michael Freiberg - Track World Champion (Omnium) 2011
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Check out our new website https://www.cyclecoach.com0 -
It's pretty self explanatory. The article presents a series of belief-based statements regarding pedalling and provides no evidence regarding the claims made. It's marketing nonsense, presumably made by someone not familiar with actual research on pedalling dynamics and performance.[url=http://www.bikeradar.com/forums/viewtopic.php?p=19715169#p19715169]Alex_Simmons/RST[/url] wrote:
That article is belief based nonsense.You are after a sausage not a figure of 8. For some reason a lot of PTs are telling clients to aim for a figure of 8. The better informed say a peanut. But Wattbike clearly shows this is not the goal.
https://wattbike.com/uk/guide/cycling_tests/pedalling_technique_test/what_the_polar_view_shapes_mean
They are fun things to play on and can at least be accurately set up unlike a typical spin bike.
Alex - are you able to expand on this comment please - I am genuinely interested
Cheers
Martin
That's not to say it's a bad trainer, just one need be very careful when interpreting such plots. They don't tell you what they claim to tell you.0 -
You also need to be careful with the calibration, they can be well out if not taken care of by the gym.Insta: ATEnduranceCoaching
ABCC Cycling Coach0 -
Fat chance down at my local gym, then!You also need to be careful with the calibration, they can be well out if not taken care of by the gym.
Been considering going over to the one at the Chris Hoy velodrome though. This thread, and a few others, may have just made my mind up for me.A fanatic is one who can’t change his mind and won’t change the subject - Churchill0 -
I will say in its defence that I produce more power with a sausage than a figure of 8 and my HR is only slightly up.0
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I will say in its defence that I produce more power with a sausage than a figure of 8 and my HR is only slightly up.
So you produce more power when your HR is higher?0 -
I said slightly higher
I'll have to look at the data to be sure,but HR is maybe 2-5% up and power maybe 20%+ up. of course this is anecdotal. Lots of other dimensions to consider.
If you focus on pedaling in circles you actually get a circular plot, the sausage is where you have a smoother push. The argument being made against, as far as I can understand is that the best cyclists don't do this.0 -
I produce more power with a sausage
Behave.0 -
LOL.
I actually find it really useful to use the Wattbike in the gym for 10-20 minutes. It gives me a chance to observe my pedalling technique, cadence, power output, heart-rate, etc., all without falling off the bike.0 -
LOL.
I actually find it really useful to use the Wattbike in the gym for 10-20 minutes. It gives me a chance to observe my pedalling technique, cadence, power output, heart-rate, etc., all without falling off the bike.
The point is though - with reference to pedalling technique - it's not telling you what you think it is.0 -
LOL.
I actually find it really useful to use the Wattbike in the gym for 10-20 minutes. It gives me a chance to observe my pedalling technique, cadence, power output, heart-rate, etc., all without falling off the bike.
The point is though - with reference to pedalling technique - it's not telling you what you think it is.
Therein lies the rub. It's reporting a net value from both cranks combined.
e.g. say at any instant the power (or torque applied) was 100 units. That 100 units could be made up of 90 from left and 10 from the right, or it could be the result of 110 from the left and -10 from the right. I think everyone would agree that each represents significantly different pedalling actions. Yet the Wattbike does not distinguish between these significantly different pedalling actions since it can only report the net downstream force from both crank arms.
To assess pedalling technique, you really need to have at a minimum independent crank measurements.0 -
How do they get away with their claims of accuracy then?
It certainly seems to "know" if you put more force on one side over the other.0 -
How do they get away with their claims of accuracy then?
It certainly seems to "know" if you put more force on one side over the other.
Yeah, I played around with this for 30 minutes last night - getting the shape to change between left and right. I was even pedalling with one leg at one point and the display was reflecting this.
So, at a simple level, I could see different efforts between left and right pedals being shown. I guess the overall power shown is aggregated but I'm sure that left and right crank torque is measure.
Also, there appeared to be two types of Wattbikes in the gym: a Trainer bike and a Pro version (according to the graphics on them). I haven't had a chance to understand the differences between the two yet.
What I focused on yesterday was my foot position - ball of foot relative to pedal axle - to see where the 'sweet spot' was.0 -
If calibrated, there's no reason to suspect the net force data is inaccurate. The data however is the combined data from both cranks. That's the point. It can be perfectly accurate net force data, however net force data is never going to inform you about actual pedalling actions.How do they get away with their claims of accuracy then?
It certainly seems to "know" if you put more force on one side over the other.0 -
[quote="[url=http://www.bikeradar.
Yeah, I played around with this for 30 minutes last night - getting the shape to change between left and right. I was even pedalling with one leg at one point and the display was reflecting this.
When pedalling with one leg, what type of shape was on the screen ?0 -
It can work out that you are not pushing with the other leg, maybe based on when the power is applied in the stroke, but if you go one legged you'll get a big circle on one side and a fullstop sized one on the other.
If you sprint and back off - you can even get a square.
The whole benefit of the wattbike profile is being able to chat to fit girls in the gym about their peanuts and sausages - great ice breaker
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It was a large circle on one side when I attempted to pedal on one leg. There was a very small circle on the non-pedalling side but hardly anything to speak of.
If I remember in the future, I'll take my camera-phone with me next time and snap a few photos of the graph/plot (Polar view) against different types of pedalling. It might make for an interesting discussion in this thread.
Whilst the overall power output is aggregated between left and right legs, when viewing the Polar view (which is the graph/plot that is supposed to be a peanut shape) you do get percentage power/effort for left and right legs also shown.
I'm still trying to understand the horizontal axis as my left leg forms a circle on the Polar view that is lower down on the X-axis. The right leg, whilst not as powerful as my left leg, forms a circle that is level with the X-axis.0 -
The whole benefit of the wattbike profile is being able to chat to fit girls in the gym about their peanuts and sausages - great ice breaker
I had an entire aerobics class to drool over for 30 minutes last night whilst I was pedalling away on the Wattbike! It's amazing how much more exertion you can manage when in the company of a bevy of beauties!0
