# How to equate trainer time to road time?



## velorider

Does anyone know a general rule of thumb that equates time spent on the trainer to time on the road? For example, 45 minutes on the trainer equals 1 hour on the road. I honestly have no idea other than the trainer time is more efficient cardiovascularly than the road time.


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## spade2you

There is no real rule. There's time and intensity. If you spend x amount of time at y watts, indoors or outdoors doesn't really factor in. Obviously if you're drilling it for 2 hours outside, a light pace for an hour inside isn't equal and vice versa.


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## Drew Eckhardt

velorider said:


> Does anyone know a general rule of thumb that equates time spent on the trainer to time on the road? For example, 45 minutes on the trainer equals 1 hour on the road. I honestly have no idea other than the trainer time is more efficient cardiovascularly than the road time.


It's very simple.

Tr * Ir^2 = Tt * It^2 where 

Tr = time on the road
Ir = intensity factor on the road (Normalized power divided by your one hour threshold power)

Tt = time on trainer
It = intensity on trainer

On the road you might run out of gears down hill and spend time at traffic lights resulting in a lower intensity factor. On the trainer you might not be able to ride as hard thus resulting in a lower intensity factor. On the road you might find it easier psychologically (perhaps because there are a lot of minor variations in power output). On the trainer you might have airconditioning so you go harder than you would outdoors when you live someplace hot.


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## Poncharelli

One of Chris Carmichael's books mentioned:

50 minutes trainer = 60 minutes outside. 

He said he came up with that after studying numerous power files over the years.


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## Ghost234

What I've found for myself is that at intensity; time on the trainer = twice as long outside. 

Doing a 300w threshold interval for 10mins inside will have me on the edge of my seat, heart rate just above threshold breathing extremely hard. 
I go outside and I have that EXACT same physiological reaction but after 20 minutes of the same wattage. 

Its been like this for me for 2 seasons now. But n=1, so don't think it applies to everyone.


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## pretender

Time on the road is spent living life; time on the trainer is subtracted from your life.


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## Drew Eckhardt

Ghost234 said:


> What I've found for myself is that at intensity; time on the trainer = twice as long outside.
> 
> Doing a 300w threshold interval for 10mins inside will have me on the edge of my seat, heart rate just above threshold breathing extremely hard.
> I go outside and I have that EXACT same physiological reaction but after 20 minutes of the same wattage.


Increased heart rate and breathing are just side effects that aren't telling you anything directly about the training that's going on in the parts of your legs you use for road cycling (growing bigger and more plentiful mitochondria and capillaries). Perhaps the reduced flywheel effect means you use your muscles less efficiently indoors.

Via Coggan's metrics the indoor session at half the length and the same intensity would have half the effect of the full length out-door interval.

I'd guess much of Carmichael's rule-of-thumb delta comes from the time you spend not pedaling out doors due to traffic, curves, etc. On today's ride 11% of my time was spent not pedaling. On my last trainer ride the number was 0.17%.


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## Alex_Simmons/RST

Ghost234 said:


> What I've found for myself is that at intensity; time on the trainer = twice as long outside.
> 
> Doing a 300w threshold interval for 10mins inside will have me on the edge of my seat, heart rate just above threshold breathing extremely hard.
> I go outside and I have that EXACT same physiological reaction but after 20 minutes of the same wattage.
> 
> Its been like this for me for 2 seasons now. But n=1, so don't think it applies to everyone.


Alex's Cycle Blog: Turbocharged Training


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## loudog

what ive found is that time on the trainer beyond 1 hour = pure misery to the 10th power. buy warm clothes, steel studded tires and a mountain bike and ride all winter long.


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## trip221

pretender said:


> Time on the road is spent living life; time on the trainer is subtracted from your life.


Love it! Now if I can only get over my fear of riding in the dark!


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## MR_GRUMPY

I adjust the resistance so that I get a similar HR for a similar speed that I do outside.

I then call it even.

I find that I can't do intervals when i'm dressed like Nannook of the North. Steady state riding is fine outdoor, but if I'm going to do hard stuff, I prefer the trainer. Trainers are great in a 40 degree garage, when it's 30 degrees out. After 5 minutes, I'm down to bibs and a jersey.


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## scottzj

I know one thing, today I did the trainer for the first time this season due to a foot injury and I sweat like a mad man. I was totally soaked from head to toe, thank goodness I had towels under the bike and on my bars haha. The spinning was much easier on the trainer, however I felt like I still got a killer cardio workout too.


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## Stephan

Been on the trainer the last half week and I realized I never sweated so much. Who knows maybe its just in my head, but riding on the trainer seems to take more effort. I was going to start a post about it, but this post seems to answer my questions. I noticed that to get the same speed and cadence as on the road I have ride in a easier gear, but I sweat like a pig. Still learning, but I realize its easier to stand on the pedals outside too.
Movation can be harder inside. Even watching TV it gets boring quick. I am trying to spend my time on the trainer doing more intervals and working on my cadence (smooth pedal stroke). Right now its about 1 hour 10mins max. Outside 1.5 to 2 hours easy.

Stephan


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## stevesbike

unless your trainer has some neutrino-based time contraction accessory, 45 minutes on a trainer = 45 minutes outdoors.


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## Pablo

People have a hard enough time comparing certain road time with other road time.


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## Wookiebiker

stevesbike said:


> unless your trainer has some neutrino-based time contraction accessory, 45 minutes on a trainer = 45 minutes outdoors.


True...However when you ride outside there are plenty of times when you are coasting (i.e. resting) while on a trainer you are pedaling the entire time.

For instance: Tuesday I did a 3 hour and 47 minute ride...of the time moving I spent 21:26 of it not pedaling at all. So technically I could have got a very similar workout only doing 3:26 on the trainer.

Also, since I was riding with others, a fair amount of that time (1 hour and 2 minutes) was done at a recovery pace (or lower) even though we were riding at a high endurance pace...on a trainer it has less variation in speeds, so again the total workout may be harder on the trainer than on the road...so less time on the trainer can again equal a greater time outdoors.

So 45 minutes on a trainer doesn't really equal 45 minutes outdoors...Unless you can get conditions where you have zero stops, no wind (even when moving) and it's flat with zero inclines or declines.


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## Schmack

For me, time on the trainer is much more effective for specific workouts, especially cardio. I get way more out of an hour of tempo intervals on the trainer than I do on the road. This consistency of ride and cardio aspects are much easier to control. That and when I get on the road, I am so jazzed that all training plans seem to go out the window, so I guess it is much easier for me to focus throughout an entire workout on the trainer.

Don't really know that I have a comparison to equate the difference.


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## stevesbike

Wookiebiker said:


> True...However when you ride outside there are plenty of times when you are coasting (i.e. resting) while on a trainer you are pedaling the entire time.
> 
> For instance: Tuesday I did a 3 hour and 47 minute ride...of the time moving I spent 21:26 of it not pedaling at all. So technically I could have got a very similar workout only doing 3:26 on the trainer.
> 
> Also, since I was riding with others, a fair amount of that time (1 hour and 2 minutes) was done at a recovery pace (or lower) even though we were riding at a high endurance pace...on a trainer it has less variation in speeds, so again the total workout may be harder on the trainer than on the road...so less time on the trainer can again equal a greater time outdoors.
> 
> So 45 minutes on a trainer doesn't really equal 45 minutes outdoors...Unless you can get conditions where you have zero stops, no wind (even when moving) and it's flat with zero inclines or declines.


I agree - I was half joking re the time contraction device. More seriously, I would suggest the OP not even try to base training load on time, or an estimate of time on the road vs. the trainer. Obviously, a power meter with kJ would let you compare objective work, or a metric such as training stress, etc. You can spin a small gear with little resistance on a trainer, which would make a time period on a trainer even less work than a light ride on the road. Choose a goal for the workout and ignore time (and ignore miles on the road as well) as a training load metric...


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## tommyrhodes

When planning my indoor workouts I try not to base it so much on time. The only workouts i really base on time are endurance rides for the most part. There's no way in hell i'm doing an endurance ride inside unless a jon and kate plus 8 marathon is on. 
Typically, i have my set interval goals, ie 5 minute intervals. I'll get on the bike, warm up, do the intervals, cool down and get off. No total time, and its the exact same thing as doing the intervals outside since your not coasting during the work period of intervals anyway.
But then again, i'm not really that fast so maybe I'm doing everything wrong.


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## spastook

pretender said:


> Time on the road is spent living life; time on the trainer is subtracted from your life.


Ya I'll second that one. I keep a Schwinn Spinmaster in my workout room but use it primarily as a clothes rack. When conditions make it my only choice I'll suffer on it for and hour or so. As far as a formula vs. actual road miles? I'd guess 60 minutes on the trainer = 90 minutes on the road but I guess that depends on the individual. I'd honestly rather have a root canal than have to ride my trainer on a daily basis.


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## BostonG

scottzj said:


> I know one thing, today I did the trainer for the first time this season due to a foot injury and I sweat like a mad man. I was totally soaked from head to toe, thank goodness I had towels under the bike and on my bars haha.





Stephan said:


> Been on the trainer the last half week and I realized I never sweated so much. Who knows maybe its just in my head, but riding on the trainer seems to take more effort. I was going to start a post about it, but this post seems to answer my questions. I noticed that to get the same speed and cadence as on the road I have ride in a easier gear, but I sweat like a pig.


You’re sweating a lot because you are inside on the trainer and there are no weather elements in play. When you’re riding on the road, the wind evaporates a lot of that sweat and keeps you a lot cooler, which may be why the trainer seems strenuous in a different way than regular road riding. Vendors sell a product that you attach to the head tube and stretch to the seat tube and it runs the length of the top tube to catch your sweat. I think I just broke a record for using the word “tube” in one sentence.

I know it sounds weird to do in the winter but after you warm up, turn on a fan. If you turn it on high and close your eyes, you can feel like you’re descending!


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## scottzj

BostonG said:


> Vendors sell a product that you attach to the head tube and stretch to the seat tube and it runs the length of the top tube to catch your sweat


Haha yes you did! Oh and I bought one of those devices from my LBS for around 24$ and it even has a flap that goes in the front of the bars to hold remotes and other things haha. I just have a TV tray that is next to the bike with food, drink, remotes, phone and spare towel.


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