Power on Trainer Vs the Road
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MarkyV posted 9 weeks ago.
A few quick thoughts here to perhaps focus the questions at hand.
First, don't worry about speed on the trainer... depending on the tension where the rubber/drum roller meet anything can happen. Watts are watts. Concern yourself with those.
As for the power disparity betwixt the trainer and open road the most liklely culprit (totally my perception here but anyway) is that on a trainer the resistant is CONSTANTLY there so in order to maintain cadence you basically have to keep constant pressure on the pedals the whole way around. Out on the open road you've got momentum on your side and can place more emphasis on down stroke (mashing) as that is the most effective pedaling stroke and not having to fight a slowing of the cadence.
Make sense?
MarkyV Racing and Coaching
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JamieM posted 9 weeks ago.
I agree with that. The one thing I would add is that riding on the trainer you'll have a tendency to heat up faster and have less ventilation to cool off. Outdoors will enhance sweat loss, which will cool you down, allowing a greater amount of work at a given heart rate.
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cjhoffmn posted 9 weeks ago.
Both suggestions make sense.
The slowing of cadence and constant pressure really seems to be key - as I was thinking that one of the reasons was that somehow the trainer slows down faster than my bike does on the road. In other words - that suggestion makes perfect sense given the way it feels. The loss of momentum for me seems big.
The heat up problem is another one that makes sense - I tend to run hot as it is. I didn't have a good workout on the trainer tonight and I really was heated up and I probably lost some serious water weight. I couldn't hold anywhere near the wattage I held on Saturday, and yet my HR wasn't really spiking either. It just all seemed harder, which could point to an overheating issue - it was perfect out on my ride Saturday.
For Reference, for the outdoor ride I'm referring to, it was exactly and hour long, my normalized wattage was about 20% higher than my average wattage, and the IF was 1.15, and the TSS was 136.5. The FTP I had set off the trainer was clearly too low, as I never really pushed myself on that ride. However, if I tried to ride tonight on the trainer at the normalized wattage from the outdoor ride I would have keeled over instead of finishing an easy/endurance ride.
I guess maybe I'm just getting adjusted/adapted to sensing the differences between riding conditions because I have the real objective data?
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MarkyV posted 9 weeks ago.
Yup... a big difference from indoor to outdoor riding. A blend of psychological and physiological factors that make riding hard indoors really really suck.
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I've been riding almost exclusively on my Trainer since January and added a PowerTap in March. I've been dutifully collecting and analyzing my data since I added the PT and can certainly see how helpful its going to be in changing my workouts.
But I have noticed something strange that I'd love to see if others have noticed or dealt with. When I first setup my trainer, I couldn't help but notice how hard I had to pedal to keep the same speeds I had pushed outdoors. I figured it was just the adjustment to a stable and true platform and that well, I simply wasn't in that great of cycling shape. I also figured it was the "always on" nature of a trainer - never a moment of rest for the legs...
When I got the PT, I was, well a bit surprised at how low my power readings were, but I figured it was more of dispelling the myths of how strong I *thought* I was vs how strong I actually am...
I racked up a fair number of miles on the PT and was getting pretty good at analyzing it. I've spotted some weaknesses, bought a copy of "Training and Racing with a Power Meter" and learned alot.
I've performed several rides on the trainer designed to really push myself and determine FTP etc. Two in particular were really hard efforts aimed at really seeing how hard I could go for 5 sec, 30 sec, 1m, 2m, 5m 20m and 30m etc. I turned in reasonable powers and started to get a sense of my FTP.
Then I went for my first outdoor ride this weekend, a simple endurance ride, well, I just simply blew everything away. My bike really felt very speedy under me, much easier to pedal than on the trainer, and my speeds were off the charts compared to the trainer. I surpassed my peak power records in some cases by better than 15%. In fact, my overall Max power was 25% higher than on the trainer - and when I did the super sprints on my trainer for the 5 sec and 30 secs, I really had jumped out of the saddled and run it really hard.
In some senses, y, I'm pretty happy, I think my winter training is paying off, on the other hand, I'm a bit puzzled. It seems that the difference between the ride on the weekend and all the training rides can't be just because I was amped up to get outdoors. My HR was certainly higher than the training rides, but it just so much easier to pedal and keep the bike moving.
It struck me that one thing might be the wheel circ setting. When I did the roll-out to set the circ, I was on the bike. But on the trainer, my weight won't be compressing the wheel. Could a few centimeters difference in Wheel Circ make that big of a difference?
Anyone experience something like this before, or have any ideas?