The Intermediate plan is the ideal progression for riders who have been following the British Cycling Foundation plan or who already been devising their own training and have a reasonable base of cycling fitness. You might be aiming to complete a 100 mile sportive, increase your sportive speed, try your hand at or progress at road racing or improve your time trialling performance. This plan will address the physiological and technical requirements to succeed in all of these goals.
If you are concerned that a plan may be too challenging for you, begin by only completing the core sessions and then, as you find your level and become stronger, you can maybe start to add in some of the bonus workouts. Conversely, if you start on the intermediate plan and find it too easy, switch onto the advanced plan or vice versa. If the core workouts of the intermediate plan seem too much for you maybe consider working through the foundation plan first or even start out following the beginners' plan.
Read more about the Intermediate 12 week plan and who it is suitable for - http://bit.ly/intermediateandadvancedplan