SRM Wattage on Trainer VS. On Road

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Rich_W
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by Rich_W

Weenie Folk -- Need some help on this one. I've read opposing views on this. Is your output while on a fixed trainer the same as on the road.

Doing my 2 x 20 intervals indoors feels a heck of a lot harder than on the road. 275 on the trainer feels like at least 325 on the road.

Any insights or discussion would be appreciated.

by Weenie


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Taz
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by Taz

I don't own a power meter but I have the same feeling with heart rate.
A certain percentage on the trainer feels a lot harder than on the road.
My solution:
Avoid the trainer.

mayhem
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by mayhem

There are several issues that can make riding a trainer feel harder than riding on the road. Primarily they are cooling issues, inertial loading and motivation.

1) Do you have a big fan (or two) blowing directly on your chest and head? What's the air temp of the room?

2) Not much do be done unless you get something like a Kurt Kinetic with the heavier flywheel.

3) Not much to be done.

Typically people are able to narrow the gap between road and trainer wattage but I suspect a lot of that has to do with motivation.

cswi9367
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by cswi9367

also, the ability to move your body around the bike as well as move the bike in some motion rather than a fixed position really makes a difference.

unit
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by unit

This really gives some great insight into how effective RPE is for training doesn't it?

Obviously watts is watts, and what you feel is perception. 275 on the trainer is no harder than on the tarmac, but you probably perceive the two differently because you are more comfortable on the road than on the trainer. If you road the trainer more, you would likely start to feel that the workout was no harder indoors (not that you really want to this time of year though).

Just to clarify though...we are talking about the same power measurement device and the same metric, right? If you are using average power on the road vs actually holding the power for the entire interval on the trainer there is your answer right there. Also do not make the mistake of thinking that two different PMs are properly calibrated/accurate/precise unless you have verified it yourself.

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Rich_W
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by Rich_W

There are no environmental factors that are bothering me. I have a ceiling fan cranked in the room, along with two huge box fans blowing on me.

I do buy the rocking the bike factor. As for the data collection... we are talking the same metric. I am using my SRM in both case... I always do the offset calibration before the workout.

My problem is the terrain near my home is very inconsistent. Lots of short ups and down... impossible to maintain a 2x20 on the down hills.

The coach I'm working with suggested moving my 2x20 efforts indoors to create a consistent load.

But daymn they are hard work! I do think I am better off doing them indoors... regardless of perception... my legs feeling like four bags of cement as opposed to the usual two...

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spaniardclimber
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by spaniardclimber

I had the same problem, I think the problem was temperature, humidity, and the traine inertias. Anyway, doing your 2x20 indoors in a trainer is a very good training, despite a lower wattage.
(Also I was able to produce way more power uphill than on the flats)

Ypsylon
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by Ypsylon

unit wrote: If you are using average power on the road vs actually holding the power for the entire interval on the trainer there is your answer right there.


But wouldn't the result be the other way around?

Steady 275 Watts is definetly easier than doing 30sec 250 / 300, if your FTP is 275. If you use NP it might be a tad easier on the road, depending on what type of rider you are.

If I get the cooling (and the music) right, I put out the higher avg on the trainer, as I don't have the small drops in power I get from varying terrain outdoors. But yeah, it's freaking hard mentaly.
"Nothing compares to the simple pleasures of a bike ride," said John F. Kennedy, a man who had the pleasure of Marilyn Monroe.

Geoff
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by Geoff

There is no question that intervals indoors can be hell on earth.

I believe that temperature and air movement are the biggest factors, but right up there is the fact that (with the exception of giant flywheels like the SRM trainer has) the load generated by the trainer is more constant than the road (even my interval course, though constantly uphill, has different grades). The mental aspect is probably the killer, though. Painful.

Tug Boat
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by Tug Boat

When I started doing my intervals on the trainer, my coach soon realized that I was not using the trainer correctly. I had the resistance way too high, which for me meant too much pressure on the tire from the roller. She suggested I back it off to where the wheel took a couple (maybe 7) seconds to spin down when I stopped pedaling. I found that to be much more manageable.

I think the reason is that there wasn't enough inertia from the drive train during the dead spots in the pedal stroke. So whenever I approached the dead spots, I had to push much harder there than on the road. I still hate doing intervals on the trainer, but my numbers match up much closer to those I generate on the road.

TB

Geoff
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by Geoff

The problem with that is the tension NEEDS to be high for intervals, otherwise you get too much slippage. You might be OK for 2x20s, but as you increase power, the tire slippage will drive you insane.

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ryan_sherlock
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by ryan_sherlock

I broke my collarbone recently and have had to do indoor work on the Turbo trainer and have noticed the same things. 380W outdoors felt like 320W indoors (same SRM bla bla bla).

I have been on the Turbo for almost 3 weeks now and the RPE/power issues has closed down a lot. For me, I think the major issues that caused the difference are:
- Motivation (getting better at that one)
- Pedaling Inertia (what Tug Boat mentioned) - I think I'm pedaling in circles a bit better now
- Less upper body movement (no tugging on bars etc... mostly due to my collarbone)

frd
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by frd

When I had a powertap I felt the same. X watts on the rollers felt much harder than the same X watts on the road.

However I use Kreitler rollers, not a trainer, so I must spin fast.
This means it's more like riding on the flats than climbing, and I feel the same difference in RPE/Power between these terrains.

erty65
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by erty65

unit wrote:This really gives some great insight into how effective RPE is for training doesn't it?

Obviously watts is watts, and what you feel is perception. 275 on the trainer is no harder than on the tarmac, but you probably perceive the two differently because you are more comfortable on the road than on the trainer. If you road the trainer more, you would likely start to feel that the workout was no harder indoors (not that you really want to this time of year though).

Just to clarify though...we are talking about the same power measurement device and the same metric, right? If you are using average power on the road vs actually holding the power for the entire interval on the trainer there is your answer right there. Also do not make the mistake of thinking that two different PMs are properly calibrated/accurate/precise unless you have verified it yourself.
My heart also perceives that it`s harder indoors, i.e. my heart rates is in the "right place", but the watt numbers are lower than outdoors.

Indoors:
Image
When the power dropped at around 1:21-1:22, i considered quitting, before making a last effort.

Outdoors:
Image

by Weenie


paintrain
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by paintrain

intervals on a trainer suck! get some rollers- they feel more like the road and consequently are 'easier'. You can also move around because your wheels aren't fixed. I always do my 2x20s on the rollers.

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