I came across this infographic that illustrates a small study that confirms what many of us perceive: Indoor training is harder than outdoor training.
I’m curious of anyone can comment on why this is (I personally don’t think it’s a mental thing, but could be wrong). Do you have experience with this topic Jonathan_Baker or anyone else here?
A lot of it is down to cooling….you need some pretty strong fans going indoors to overcome the additional heat your body is generating.
For me it’s a function of cooling, distractions (the benefit of them outside as the scenery changes) and the feeling of making progress (outside). To combat these I have 2 of the Lasko fans (still could use more cooling), music and executing the workouts on Zwift. Even if I’m doing them in ERG mode, just the perception of moving through the (virtual) world helps, and passing other people or seeing them pass me helps. An odd thing for me is that too much distraction is a negative. If I’m trying to watch a bike race (on mute), Zwift running in the background, and music, then that’s too much. May be just a me thing.
It’s cooling. Similarly I find slow climbing efforts harder than the same watts on the flats.
My own thoughts:
I’m sure there are other factors, that make riding indoors as “fun” as its. With that said, interactive trainers and the software available to control and provide visuals has made the experience a lot better. In 198x (I can’t remember the exact year) I bought my first trainer. It had a tiny roller that was actually toothed, not smooth. The little turbine cage was, uhm, little. I’ll bet the whole rotating part of the trainer weighed maybe a pound. There was no flywheel. I’ve had farts that had more inertia than that thing had, and no, I don’t mean rotational inertia either. The moment of inertia of that setup was so close to zero, the it could be nearly exactly calculated by linearizing it. After all, its linear inertia was zero.
Good point on the whole trainer/inertia discussion. That’s been my line of thinking here too, beyond the obvious cooling/movement downsides of being locked on an indoor trainer.
Most of us are conditioned to riding outside. Jumping on a trainer can feel completely foreign from a muscle-memory perspective. Riding at threshold on something like a LeMond Revolution vs a RevBox is a night-and-day experience. (And by “different,” I mean you’ll want to yeet the RevBox into the bin after a few minutes).
Fast-forward to the modern era of trainers, and ride feel/inertia still varies a lot between models. Add virtual shifting into the mix, and things get even messier because the flywheel speed is tied to cadence, not gear selection.
I think this gets to the heart of my question. The fact that there is much less ‘roll’ (i.e. inertia) on a trainer at a higher wattage than out on the road seems like it would make it more difficult. The LeMond trainer (which has a wonderful feel) is a great example of this difference compared to a magnetic trainer.
Apart from cooling, which is probably the biggest factor by a kilometer, one’s choice of gear ratios makes a difference, too. Even factoring out ride feel, even outdoors it matters whether I climb or on a false flat. My self-selected cadence is different and I think I can put out more power on a climb, provided there is enough of a breeze to keep me cool.
On the trainer my average (self-selected) cadence is 5–10 rpm higher than on the road, for instance, I spin a lot more. At 98–103 rpm my pedal stroke is different than at, say, 70–80 rpm. My pedal stroke need not be as “round”, because I can simply rely on the flywheels/wheels rotational inertia rather than on the smoothness of my pedal stroke.
I wouldn’t count out psychology, too, being on a trainer is much more monotonous and there is no sense of progress apart from your interval timer. Although I reckon this is more of an issue for longer efforts. I feel much safer on a trainer for sharp, short efforts since all I need to pay attention to is power and not dying. 
I bought a Feedback Sports Omnium trainer to take with me when I was traveling while preparing for Unbound. I had a pretty healthy travel schedule and couldn’t afford gaps in my training.
The second I got on the Omnium, I was yanked into the past of crappy magnetic and wind resistance trainers. No “road feel”, no wheel momentum, etc. Honestly, anything over a Z2 effort was unpleasant.
That is NOT a knock on the Omnium. For what it is, it is a great trainer. But the difference is stark!
I’ve avoided indoor trainers for decades. But there was a time when I did ride indoors on rollers. As noted by others, the cooling thing is a big big issue. For me, other factors include boredom. That’s mentally taxing, as was staying focused on rollers for 45-90 minutes at a time.
Yeah, my Ave HR on rollers is definitely influenced by spikes caused by drifts to the edges when I lose focus for a second or two.
I don’t think I buy this. Apart from the matter of heat dissipation, I think riding a stationary bike is easier in some ways.
On the other hand, there aren’t any hour-long climbs where I live, but I can ride the Stelvio in my garage.
I agree that it is harder. For me, it’s because I pedal constantly (wanting it to finish sooner?) whereas on the road I can have a bludge occasionally & enjoy the cooling effect of the wind. The other things you have to concentrate on whilst out on the road also help to take your mind off most other things other than steep climbs of course!
This is my understanding as well. Inertia makes a huge difference to some people, you actually get a whole load of people who have better numbers on the turbo as well (I am definitely not one of them).
I seem to remember a lengthy discussion with Coogan etc on this subject on TTF (UK TT forum), the shape of peoples pedal stroke was also suspected to be a significant factor - which would make sense in the context of inertia. I’ve also noticed this outside, friends of mine are super strong uphill but struggle to apply the same amount of power on the flats. The angle of riding uphill effective alters your power phase which works really well for some riders pedal stroke, riding uphill also tends to be at a lower interia.
My indoor sessions now are sweetspot / endurance based stuff only. Any really hard intervals are done outside, as I know I’m significantly stronger outside so the physiological response is higher i.e. they work better as I’m working at my actual limits, rather than the ceiling imposed by being indoors.
I was just going to say this. I agree 100%!
Just putting my scientist hat on, the first thing I thought of was “where are the error bars and were these differences statistically significant?”.
The absence of such data makes me think the differences are not “significant” and so my response is, there’s nothing to discuss apart from sloppy data gathering.
EDIT: Found the original article. Paper is behind a pay wall, so hard to tell but the abstract states:
Across all maximum mean power test durations, the trimmed mean power was higher outdoors compared with indoor testing (P < .05).
So we can say results were statistically significant.
I am someone who does ~80% of my rides indoors but anything higher than tempo (maaaybe sweet spot) needs to be done outdoors to hit my #s. However, I can do my best 3-4hr power on the trainer / hitting levels that are near impossible outside (Due to streadyness but also ability to focus really hard when I get fatigued indoors)
I’m not sure why it is … but I’ve worked for 8ish years to try and fix it. I’ve installed an AC unit, gotten 3 fans, rocker plate, different bikes and none of it matters. Just can’t seem to hit the #s
If I had to guess, it’s about distractions outdoors (wind, focusing on not killing myself) and then ability to really thrash / rock the bike outsidey
Le Mond Revolution user here reading this cooling off from a Trainer Road session. Any current trainers that have similar ride feel? I’ve been thinking about getting something newer since the lack of through axle compatibility means I have to use an old bike and although I have a speed sensor on it, the “dumb” nature of the trainer means it doesn’t work as well with interactive platforms. I’ve tried a few others over the years, but none felt as much like a real ride as the LeMond.
