Wattage. Shouldn't it all be the same?

[laupsi]

For those road purists out there this may not be a question for you.

Training indoors due to poor weather, daylight, etc... and doing interval training at 300 watts. Does 300 watts indoors equate to 300 watts outdoors? Same bike, wattage meter, person, different perceived rate of difficulty. Riding 300 watts indoors equates to about 350 watts outdoors IMO. Why?

[54ny77]

Three zero zero bike-a-watts? Great scott!

http://allsportcrossfit.com/wp-content/uploads/2012/10/gigawatts.jpg

[EDS]

For those road purists out there this may not be a question for you.

Training indoors due to poor weather, daylight, etc... and doing interval training at 300 watts. Does 300 watts indoors equate to 300 watts outdoors? Same bike, wattage meter, person, different perceived rate of difficulty. Riding 300 watts indoors equates to about 350 watts outdoors IMO. Why?

For me, the big issue indoors is overheating.

[christian]

Yeah, it's the heat.

For the same watts, RPE and HR will be higher indoors. Huge box fans and Vornado fans and ice cold drinks helps, but it's one of the big reasons I struggle to do 60+ minute workouts indoors.

[laupsi]

For me, the big issue indoors is overheating.

not doing for periods of more than 3-5 minutes of a clip before recovery. this is very difficult for me mind you and it's almost unbearable to do more than 2 sets indoors; HR wise, temp wise, fatigue wise, all of the above.

Outdoors, and granted I usually cannot find a hill long enough for a 5 minute interval at a steady 300W, but the overall effort, regardless of the time, doesn't "feel" as extreme.

[Mark McM]

For me, the big issue indoors is overheating.

The human body is only about 25% efficient, so to put 300 Watts on the pedals, the cyclist is burning closer to 1200 Watts. Isn't that the power rating of a typical microwave oven?

[krismac23]

From what my coach tells me from training indoor versus out Doris the differance in the resistance in a trainer. The trainer resistance is constant, hence why the bike stops quicker when you coast. You don't get the benefit of coasting inside, theirs no momentum to keep you going. All this equates to indoors being harder in its own way. But it doesn't mean indoor trainning is better. You can't simulate real world road feel like terrain and etc.

[laupsi]

From what my coach tells me from training indoor versus out Doris the differance in the resistance in a trainer. The trainer resistance is constant, hence why the bike stops quicker when you coast. You don't get the benefit of coasting inside, theirs no momentum to keep you going. All this equates to indoors being harder in its own way. But it doesn't mean indoor trainning is better. You can't simulate real world road feel like terrain and etc.

thanks this is good information and I totally agree. never the same as when I have time to ride outdoors regardless of the effort.

[carpediemracing]

Watts as measured by the powermeter will be the same. The strain gauges etc react to force regardless of whether the bike is indoors, outdoors, on a trainer, on the road.

What makes the difference is that a trainer/rollers/etc isn't like being on the road. You can't rock your bike, for example, and when you do your instinct is to rock in reverse of how you rock the bike outside. This is why the Kurt Rock and Road is popular.

Another is inertia. The trainer can't replicate the inertia you have outside. This is why heavier flywheels are popular. There's an element of pedal-coast that you miss on the trainer - you can't relax your legs mid stroke regularly on a trainer because you'll slow. On the road, with you and your bike rolling along, you can coast a bit more. For example out on the road I often soft pedal down a slight grade and then "pick up" the pedals as the road flattens out. I can make a pretty steady effort in a big gear. There's no replicating that on a trainer.

Finally there's the actual contact point between the bike and whatever (road, trainer, etc). On a trainer you're limited to about 1000-1100w for a typical roller. This is why devices like the Lemond trainer exist - they replace the slippery contact point with one that's not so slippery.

As far as overheating... I find riding the trainer much more comfortable than riding outside for much of the year. In the winter it's cold outside, in the summer it's hot. I have one big fan, sometimes two, and my best 10 and 20 minute efforts have been on the trainer.

[MattTuck]

The great irony is that riding trainers indoors is best suited for short interval workouts (and as noted above) not long steady state workouts. It is ironic because the winter is allegedly the time when you should be doing longer low intensity work.... oh well.

[Vientomas]

Does wind resistant play a role? None while stationary indoors.

[laupsi]

The great irony is that riding trainers indoors is best suited for short interval workouts (and as noted above) not long steady state workouts. It is ironic because the winter is allegedly the time when you should be doing longer low intensity work.... oh well.

it's Spring!

[shovelhd]

Inertia, lack of proper cooling, CO buildup in the room, high intensity form goes away. My coach derates 7%, to me it's more like 10%.

[laupsi]

Inertia, lack of proper cooling, CO buildup in the room, high intensity form goes away. My coach derates 7%, to me it's more like 10%.

okay then so it's pretty much a consensus; riding indoors affects ability based on several factors. glad it isn't just me! :)

[firerescuefin]

Does wind resistant play a role? None while stationary indoors.

..but you're not overcoming it indoors..so no.

[fuzzalow]

Inertia, lack of proper cooling, CO buildup in the room, high intensity form goes away. My coach derates 7%, to me it's more like 10%.

Now there's the discovery. Instead of boosting hemotocrit by sleeping in an altitude tent, go one better - workout in an O2 depleted room. The programs workout intensity is self limiting - go too hard and you pass out.

[wallymann]

...is in the ramp-up of resistance on a trainer not matching the real world in many cases.

very good fluid resistance trainers, like the kurt kinetic, which match real-world ramp-up of rolling resistance very well for riding on flat ground in still air conditions. so they're great for getting into shape and building a solid aerobic base, which is the hardest thing to do for time- or weather-challenged cyclist.

but trying to get a resistance unit load to ramp-up and mimic any sort of gradient will take something extra.

there are computer-controlled magload trainers like the TACX, but IMO those are worse than the KK resistance unit -- i've owned both. even though they're computer controlled, they change settings on a mag-load resistance unit in "steps" which means the slope/curve of the ramp-up is not smooth or consistent as it would be in the real world.

[jh_on_the_cape]

If measuring power at the rear hub or BB, this does not matter when doing intervals (not coasting). You are putting out power to overcome something outdoors or indoors, wind resistance or indoors it's whatever is in the guts of the trainer.

The real reasons it is harder on a trainer is what people have mentioned: you are less efficient due to overheating etc.

Has anyone ever tried putting the trainer outdoors on a nice day with a mild breeze? I realize that this is silly (unless you are... on ship?), but would test the idea about heat, CO, etc. That would isolate the differences arising from the trainer itself.

From what my coach tells me from training indoor versus out Doris the differance in the resistance in a trainer. The trainer resistance is constant, hence why the bike stops quicker when you coast. You don't get the benefit of coasting inside, theirs no momentum to keep you going. All this equates to indoors being harder in its own way. But it doesn't mean indoor trainning is better. You can't simulate real world road feel like terrain and etc.

[slidey]

Umm, not quite sure this is entirely true. For me, rollers helped with tempo...i.e. sustained long intervals (60-75mins) of Zone 3 effort, but did nothing for my snap i.e. jumping on moves in a race, etc. Why you ask, well that's because that's how I setup my training on the trainer...going steady, and long at a high threshold.

What I guess I'm saying is that you can develop your strengths on a trainer/road based on your workout regimen. However, I've found training on the road to be more realistic or easy to relate to, for obvious reasons.

The great irony is that riding trainers indoors is best suited for short interval workouts (and as noted above) not long steady state workouts. It is ironic because the winter is allegedly the time when you should be doing longer low intensity work.... oh well.