Stationary 101

Typically you will try to keep to your optimum cadence, which is around 90 rpm. You usually use your gears to vary your intensity to the required level. If your trainer has variable intensity it is often easiest to find a setting which allows you to get to your desired intensity range just using your gears.

An exception to the above is where your specifically training for fast leg speed or varying your leg speed. This should be part of your program. Mtb'ers ride with a higher range of cadences compared to other forms of cycling such as road, and the ability to suddenly increase leg speed helps your acceleration.

Working at low cadence isn't normally part of a program, for me it gives me sore knees.

Good luck - the indoor trainer is true "hall of pain" stuff but it really has the potential to pay dividends

how long should i be spining for minutes or hours or km..

The.flying.al makes a good suggestion with that program/book.

Don't make the mistake of just sitting there and staying at one zone. Also you need to work out if your trainer is equivalent to a flat ride or a climb, and does it ramp up as you go faster - or does it have adjustable settings.

Suggestions for a session in a training program is set out below. Note that this can vary depending on where you are in the program as you work towards peaking and tapering for an event. The example is for a session on a stationary non-adjustable FLUID trainer. To raise or lower HR is a matter of changing gears to achieve the HR*cadence desired for the session. Note that where you are in your training program will determine the level of intensity you aim for and when you want to peak. Don't forget to taper as you get close to an event. (MHR = Max Heart Rate - DON'T use 220-age!)

Example
Total exercise time: between 60 and 180 minute (this varies depending on fitness and where in training program you are)s
1) General pace @ 90-100 RPM @ 75% MHR
2) Increased effort 6X5KM (or time equivalent) efforts @ 80-85% MHR @ 95 RPM. These efforts can vary from 3 efforts of 3km (or time equivalent) to 2*10km to 6*5km through to 2*20 and other variations as you develop fitness.
3) Recover after each increased effort for 5 minutes @ 70% MHR @ 85 RPM then into second effort or general pace. Again the recovery phase time can vary depending on where you are in the program but 70% MHR is appropriate. Note that it may take awhile for your HR to reduce to 70% after an effort and if use a short recovery time you may not get the HR down to 70%. But that is ok.

Some points:
Always use a slick tyre if using an mtb.
Always have one or two fans on you, even in air con.
Always take fuel (drink and food) as you would when racing or riding.
The RPM above assumes the riders efficient RPM is 90 to 95.
Max HR is known or accurately estimated, eg Males - MHR = 202 - (0.55 x age), Female - MHR = 216 - (1.09 x age) http://www.brianmac.co.uk/maxhr.htm

Of course if you don't like 2 or more hours on the trainer try the 30 sec sprint model, but it is HARD . Set the general effort then after warm up do 5*30 seconds sprints, working up to 100% effort as you progress, 2 minute recover back at general then sprint. http://sportsmedicine.about.com/od/sampleworkout...

HTH

I love training related posts, and usually get carried away, so I'll limit it to one comment re RPM and spinning.
On the road, 95-105rpm is optimal - on a smooth surface, with steady, regular gradient, with closely spaced gear ratios. As such, doing that sort of thing on the trainer is good - for your road riding, general fitness, and pedalling skills.
MTB riders rarely, if ever, are able to maintain such a high cadence, even on a fire-road.
If you are training a bit for MTB, dont be afraid of including some low cadence / high force efforts too. MTB racing is super explosive and requires massive moments of force (imagine turning a switch-back, up a hill, and having to raise your front wheel over a root at the same time - not gonna be 100rpm!).

If you must ride an indoor trainer make the most of it and get your self some spinnerval dvds.

http://www.everestsports.com.au/spinervals/index...

There is a fitness series for those just looking to get fit or drop weight and a competition series that focus more on getting fast.

if you can get a couple of different ones so you can work on one thing for a few weeks ie base fitness, and then switch it up with some strength, endurance or fast twitch stuff

If you are training a bit for MTB, dont be afraid of including some low cadence / high force efforts too. MTB racing is super explosive and requires massive moments of force (imagine turning a switch-back, up a hill, and having to raise your front wheel over a root at the same time - not gonna be 100rpm!).

Actually I find I spin and higher cadence on the MTB. As a bigger guy I find it much easier to be spinning at a high cadence to accelerate out of a corner than it is to push a big gear at lower cadence. But it's so personal best to work out what works for you