Determing miles for spin class or trainer ride

There's really no consistent way to do this--for this reason I log my cycling in time rather than distance (although I make sure to know distances for long rides to ensure proper training to a distance, since that's what races are marked in).

If you get a bike computer ($20 or so for the cheapies), that will register miles on your trainer.

Then, you could pick what seems to be an average distance that you manage to cover on an average ride on average terrain, and just apply that to time you spend doing indoor cycling.

I have a $35 cyclocomputer on my bike that measures speed, cadence, distance, time, avg speed, etc.  It's always on the bike, whether on the trainer or outside.  If you figure out with the cyclocomputer your average speed inside or out, you can use that as a rough estimate of distance in spin class.

Brian

 i understand that sentiment.  i can't even log it if i don't have a distance.  it drives me insane as well so don't feel alone.  i don't even try to get past it anymore.  i can't wait to see if you'll attempt the do-it-yourself sensor move, that'll tell just how badly you want to know those miles.

I do the exact same thing.  I usually underestimate my miles by a couple just to not inflate the totals.  The way I see it, my heart only knows how fast it's beating and for how long.  My heart doesn't know squat about miles.  So as long as I'm doing the time in my right HR zone, I'm good.

IMO, the only thing good about logging miles is to have some kind of record to reflect on or brag about.  I'm sure I probably have 10%-20% more miles in reality than shown in my logs - but that's not a big deal to me.

BTW - having a computer sensor on the rear wheel of your bike on the trainer does not work IMHO.  So save your money if your are going to buy and extra.

On trainers, you can set the resistance from easy to hard.  If you set it too easy, you can put your bike in the big gears and get the wheel flying at a certain HR - as if you are doing 30 mph.  OR you can set the resistance to something really hard and then push a small gear at the SAME HR  - and it will look like you are doing 7 mph.

So if you do the same amount of work (consitant HR for 1 hour, let's say).  The first example has you going 30 miles, the second is 7 miles.  So which is right?

Taking your average speed based on typical road conditions when you ride outside and assuming you are doing the same pace if you are riding at approximatly the same intensity is probably more accurate IMO.

I'll completely disagree with that one ....... same logic behind running on a treadmill .... would you tell people not to log the miles they run there???

Yes, the onus is on the rider to ensure that they get as close to road feel as they can.  For me that is the hardest setting for the resistence which based on my experience translates very well to the road, so I am fairly confident in putting the miles in the log accordingly.  In fact on the hardest setting I actually am a tick slower than I would be on a similarly flat route on the road with light winds, so it is even more of a confidence booster when I can spin a 39 x 15 at 100+ rpms for a 1/2 hour easily (20.5 mph or so).

First response, I didn't say NOT to log miles, there are just more accurate ways for a beginner to estimate IMO.  Also, my plan has me running based on HR and time.  So in reality, it probably doesn't matter to me if I log miles either (but I do).  I can set the treadmill at 0% incline and run faster/farther in an hour at a given HR than if I set it at 15%.  So which is right?  I have found that 1%-2% seems to simulate a flat outdoor conditions.

Second response - I think I mentioned that if you tune your trainer to reflect outdoor conditions, you would have decent numbers, like you have done.  But a beginner may not know how to do that...  Just saying....

Easy, your distance traveled is zero.

Yes .. always the best method!!