This time of year I'm often asked about indoor bike workouts on a trainer. I would much rather have the athlete training outdoors, but realize this isn't always possible due to weather and short days. The most frequent question I get has to do with how long these rides should be. The potential benefits of riding indoors are not much different than riding outdoors. However, indoor training is much more mentally difficult than riding outdoors for most athletes. Motivation is likely to suffer. I’d much rather coach someone who is highly motivated but has low fitness than the other way around. So I generally make the indoor rides shorter than what the schedule called for had the ride been outside. And after 2 or 3 back-to-back indoor rides I'd prefer the athlete did something else such as run, XC ski, swim, snowshoe, off-road ride on MTB/CX bike, etc. So with this in mind, a general guideline based on periodization that I use for the longest weekly ride indoors with those I coach is as follows…
Base 1: 1-1.5h
Base 2: 1.5-2.5h
Base 3: 2-3h
Build: full duration as if outdoors
If the above is longer than what the rider would normally be doing at that time of year (sprint-distance triathlete, crit racer, etc) then I may still shorten the ride below what is suggested above. Again, motivation trumps fitness.

I would find a 2-3 hour indoor ride psychologically damaging! Everyone is different, and winters are not as severe in Australia, however 90mins is about my personal boredom threshold.
Thank you Joe for sharing all of you knowledge on this site - much appreciated.
Posted by: Andrew | 12/23/2010 at 03:22 PM
Andrew--I certainly understand. For me it's about an hour regardless of when in season. Used to do as much as 4hrs when I lived in Colorado in the winter. Now with my winters in Scottsdale I almost never have to ride indoors. I believe I did once about 2 years ago. Thanks for your comment.
Posted by: Joe Friel | 12/23/2010 at 03:39 PM
I was able to race a 200km team road race in just over 6 hours just on indoor training (1hr x 3) midweek and 2 x 100km on Sat and Sunday outdoors. I love my indoor trainer, it really has its benefits.
Posted by: Lauren | 12/23/2010 at 09:04 PM
On a slightly different note, is there any difference between long rides on a MTB and a tri bike? I go much slower on the MTB because of the heavy weight of the bike. I base the workout on perceived effort. Do you change the recommended time for long workouts based on whether it's a tri bike or a MTB?
I plan to avoid indoor workouts as much as possible this winter (except for swimming). I don't have a trainer and stationary bikes cause hip flexor problems for me now. I was fine a couple years ago, even managing to do some 3-hr. sessions on the stationary bike. Now I get hip flexor tightness within 10 min. on the stationary bike, but never on a regular bike. Maybe I'll do an occasional workout on the spin bikes at the gym.
Enjoy the holidays Joe.
Posted by: Michael H. | 12/24/2010 at 07:06 AM
Since I picked up a computrainer, having the motivating to ride more than 2 hours, and even 4+ hours somedays (last winter), has become much much easier....I wouldn't even touch my regular trainer now. It is definitely worth the investment. Indoor riding is also a good time to tease the mind with music/video stimulation as much as possible, not movies, but bike race videos and trance music mixes...or whatever music you prefer during your workout. The winter indoor rides are also a time for intense visualization....think about those times where you got dropped last year in a race, or not performed at your absolute best...and missed the break (bike racing in my case). Play those scenarios in your mind and visualize yourself performing better in the coming year. When you actually find yourself in that position in your next race, it will be as if you were already there and you will hold that wheel, make the break, and hang on for a sprint win. Right? Then next thing you now, your required time on the bike indoors will have passed and you will find so much satisfaction and be motivated to ride indoors the next time the weather does not permit an outdoor ride.
Posted by: Frank O | 12/24/2010 at 07:07 AM
Michael H--The MTB is a great alternative to road and indoor riding in the base period regardless of your cycling sport. Going much more slowly is to be expected. It can also be much more full-body tiring than road riding. Since overall fatigue may be an issue your longest MTB ride may be somewhat shorter than your road ride.
Posted by: Joe Friel | 12/24/2010 at 07:14 AM
A lot of times in the frozen midwest winter I find myself needing a ride that's longer than what I can do or is advisable outside and longer than what I can stand on the trainer (ie, needing to ride 3-5hrs when it's in the 20s outside). I've found a good solution to this - when it's too cold outside to do all your ride (especially a long one), it's often possible to do 1-2hrs outside and come back and get on the trainer for another 1-2hrs, possibly with some specific work, to cap off your ride. Sure beats the mental burnout of a long endurance ride on the trainer.
Posted by: Douglas | 12/26/2010 at 03:55 PM
I have a random question for you. I have been hearing a lot about the health benefits of coconut water and was wondering what you thought. I know that some say it is a better replacement than leading sports drinks for replenishing electrolytes after workouts as well as an all around good source of potassium. Your thoughts? Thanks!
Rebecca
Posted by: Rebecca | 12/26/2010 at 06:20 PM
I love indoor ride and thanks for this valuable post! i loved this site and have bookmarked!!
Posted by: Training Needs Questionnaire | 12/27/2010 at 01:57 AM
Rebecca--I don't know. Sorry I can't be of help here.
Posted by: Joe Friel | 12/27/2010 at 07:50 AM
Hi Joe,
Personally I don't really mind riding indoors at all and find it necessary that I do very long rides indoors here in Wisconsin to compete at the top level in Pro Mountain Biking. I just make sure the power meter numbers are right on and play games on the laptop or surf internet etc. This is a special case though, as I need to be in top shape to compete as a Pro in the early spring.
I do have a question though. I am noticing the trainer power output is much lower than the outdoor power output. 5 hour ride inside is 20-30 watts lower on avg than an outside ride, and this is with all thing being equal (cadence, power meter setting, HR, RPE etc.). I have heard similar experiences from other cyclists and we all have theories, mostly about continual drag on the motion. Thought this may make a good topic of discussion. Thanks for all your work in the field, I owe much of my success to learning from your books and efforts in coaching and training!
Posted by: Nathan Guerra | 12/31/2010 at 02:54 PM
Nathan G--What you may be seeing is HR high rather than power low. Cooling is a major issue indoors.
Posted by: Joe Friel | 01/01/2011 at 07:13 AM
Hi Joe, what would be a good parameter measure for HR in indoor training (I don't use a power meter)? I mean, if my outdoor zone 2 is 142-150, when riding indoor I have the sensation such a range would mean more muscular effort (my trainer is Cycleops Fluid 2, which I definitely think works fine). Should I just do an effort, let's say, 10-15 pulses lower, as it would be me instinctive tendency? Best regards and happy 2011!
Posted by: Carlos Cuenca | 01/01/2011 at 12:45 PM
Carlos C--I don't know. But I understand having been there myself. There really isn't any physiological reason why HR would be different on a trainer than on the road. A minor difference is that on the road the bike moves side to side while the body is relatively still, but on the trainer the bike is locked in so your body moves side to side. That affects economy but I doubt if it's enough to make a big difference in effort/HR. The only major difference possibly is that it's hotter indoors. Perhaps you (and all of us) just need more fans.
Posted by: Joe Friel | 01/02/2011 at 01:48 PM
Hello,
if I set annual hours to 400 then from table in your book I got longest rides for Base1: week1-1:50h, w2-2:10h, w3-2:25h. So, all of them can be catted to 1:00-1:30h? Then those rides will be equivalent to other (shorter) day times. Is it ok? Thank you!
Posted by: ieris | 01/06/2011 at 03:37 AM
I have a question about how to compare indoor training rides with outdoor ones with respect to training effect. I have the impression that a 3 hour ride outside is short, while the same 3 hours inside is long. Now, on the one hand, it is pretty clear why: inside I pedal non-stop, outside there are stop signs, downhills, etc. But on the other hand, judging in terms of HR (I don't have power) the efforts are about the same (indeed riding outside my HR is likely to be slightly higher). When replacing a long ride outside with one on the trainer (or vice versa) ought I to perform some sort of calculation to compensate for the differences between the two (or are there really no differences)?
Thanks!
Posted by: Brad | 01/07/2011 at 07:58 AM
Brad--There _may_ be a 10-20% difference when riding indoors (harder). Consider adjusting accordingly. There is no science here. Your opinion is as good as anyone's.
Posted by: Joe Friel | 01/07/2011 at 09:28 AM
Joel - I have been using Training Peaks for the last 18 months and it took me from a couch potato to a top 15 place in my age group in the ITU world series in my first year of competition (2010); so I am a great admirer of your work! I have a question: my HR while training on a turbo trainer is about 10 bpm lower than on the road for the same perceived effort (no power meter). While on the road it's not a problem to do a 6-min interval in z4, on a trainer I can only get to zone 3 even if I push myself very hard. Have you ever experienced this before?
Posted by: Enrico | 02/01/2011 at 09:46 PM
Enrico--Read this and see if it helps any...
http://www.joefrielsblog.com/2011/01/indoor-vs-outdoor-bike-performance.html
Posted by: Joe Friel | 02/02/2011 at 12:36 PM