After determining your goals for the year, the next step is to select the races that will allow you the best chance to attain your goals.  For example, if one of your goals is to run a specific trail marathon personal record (PR) time, then look for races that are at the appropriate altitude and course elevation profile that enable you to achieving your goal.  This might be a trail marathon that features a generally downward elevation profile similar to the Deadwood Marathon in South Dakota.

Examine the year long racing calendar and determine supporting races for your goal this year.  Supporting races may have shorter lengths or less aggressive terrain, but will nevertheless prepare your body for your goal achievement races.  Ensure there is enough recovery time between races.  A common mistake is to end up with a race schedule that starts very early, ends late, and has you racing on every weekend...this is typically a prescription for disaster leading to mental burnout prior to your key races of the season or worse: over-training injuries.  Beyond enduring the mental stress of a packed racing calendar is the very real chance of injuring yourself either through over-use or from an acute injury because of fatigue. 

Building a Base: The concept behind supporting races is to slowly move up the stress-response curve.  There is a fine line between applying enough stress to elicit the optimal response (increased performance due to positive physical adaptations to stress) and too much stress which can lead to injury and burnout. Progressive stress takes the form of building the aerobic base in the early months of the season.  This is where you slowly build up a base of long runs at slower speeds to increase your running endurance base.  The length of your long run is dependant on your goals for the season, but the general guideline is to increase no more than 10% of your distance per week.  If you are training multiple disciplines (as you must for adventure races and other multi-sport races), examine the total volume of training and limit yourself to an average 10% increase from week to week.  In cycling, spin at a higher cadence and do not push big gears too soon.  A general guideline is to spin 750-1000 miles as a base prior to moving into strength and pushing larger gears.  The base phase should take anywhere from 8-12 weeks depending on such variables as current fitness state and amount of training time available to you per week.  Supporting races during the base phase provide the correct distances albeit at lower speeds, and act as progress checks against your plan and fitness objectives.

Sample base building phase workouts [example week]:

The key training event in the base building phase is the long run.  In the early weeks and months, depending on your fitness level, the long run is the central theme for each training week and transitions to every other week or third week as you extend your long run mileage into ultra distances (greater than a marathon).

The next phase of training focuses on building strength from the foundation you developed in the base phase.  The total training volume may decline and more rest days may be required as you progress towards higher intensity but shorter workouts.  These might be hill repeats, or hill surges of 60 to 90 seconds with 30 seconds of rest (light jogging), working up to 12 or 14 repetitions.  Supporting races in this phase might be running or biking hill climbs or time trials like the Mount Evens Hill climb.  During the strength building phase, you can alternate hill repeat training on the weeks you do not plan on long distance running.

After the base and strength phases comes the speed phase in which the training becomes more intense, but shorter in duration.  Speed phase workout could be a combination of intervals and fartlek (Swedish for speed play).

Next: Intervals the key to developing speed>>

The last and often neglected phase prior to competing in your goal attaining races is the taper phase.  Too often the taper phase is overlooked or neglected, or worse, the athlete opts for cramming in "one more training session" instead of resting and recovering for the main event.