Once again, I am featuring this article which I copied from www.running.competitor.com and posted it in my blog to make it a permanent reference to my readers.

If you want to run your best, you’ve got to do a variety of workouts. Here’s how. 

There are eight basic types of runs that are practiced by runners of all levels everywhere. These formats evolved through a global trial-and-error process over many decades. They survived because they work. If you want to get the most out of the time you devote to training, you will need to learn and practice them too. You can add all kinds of wrinkles to these formats (for example by combining two of them within a single session), but even in their most basic form these workouts will take you far. 

Recovery Run 

A recovery run is a relatively short run performed at a steady, slow pace. Recovery runs serve to add a little mileage to a runner’s training without taking away from performance in the harder, more important workouts that precede and follow them. Recovery runs are best done as the next run after a hard workout such as an interval run. Do your recovery runs as slowly as necessary to feel relatively comfortable despite lingering fatigue from your previous run. 

Example: 4 miles easy 

Base Run 

A base run is a relatively short to moderate-length run undertaken at a runner’s natural pace. While individual base runs are not meant to be challenging, they are meant to be done frequently, and in the aggregate they stimulate big improvements in aerobic capacity, endurance, and running economy. 

Example: 6 miles at natural pace 

Long Run 

Generally, a long run is simply a base run that lasts long enough to leave a runner moderately to severely fatigued.  The function of a long run is to increase raw endurance. The distance or duration required to achieve this effect depends, of course, on your current level of endurance. As a general rule, your longest run should be long enough to give you confidence that raw endurance will not limit you in races. 

Example: 15 miles at natural pace 

Progression Run 

A progression run is a run that begins at a runner’s natural pace and ends with a faster segment at anywhere from marathon to 10K pace.  These runs are generally intended to be moderately challenging—harder than base runs but easier than most threshold and interval runs. 

Example: 5 miles at natural pace + 1 mile at half-marathon pace 

Fartlek Run 

A fartlek run is a base run sprinkled with short, fast intervals. You can think of a fartlek run as a gentle interval session.  It’s a good way to begin the process of developing efficiency and fatigue resistance at faster speeds in the early phases of the training cycle, or to get a moderate dose of fast running later in the training cycle in addition to the larger doses provided by tempo/threshold and interval workouts. 

Example: 6 miles at natural pace with 6 x 30 seconds at 5K race pace scattered throughout 

Hill Repetitions 

Hill repetitions are repeated short segments of hard uphill running. They increase aerobic power, high-intensity fatigue resistance, pain tolerance, and run-specific strength. The ideal hill on which to run hill repetitions features a steady, moderate gradient (4-6 percent). Hill repetitions are typically done at the end of the base-building period as a relatively safe way to introduce harder high-intensity training into the program. 

Example: 2 miles of easy jogging (warm-up) + 10 x 1 minute uphill at roughly 1500m race effort with 2.5-minute jogging recoveries + 2 miles easy jogging (cool-down) 

Tempo Run 

A tempo run is a workout that features one or two sustained efforts somewhere in the range of lactate threshold intensity, which is the fastest pace that can be sustained for one hour in highly fit runners and the fastest pace that can be sustained for 20 minutes in less fit runners.  Tempo/threshold runs serve to increase the speed you can sustain for a prolonged period of time and to increase the time you can sustain a relatively fast pace. 

Example: 1 mile of easy jogging (warm-up) + 4 miles at lactate threshold pace + 1 mile of easy jogging (cool-down) 

There is a special type of tempo run that is known as a marathon-pace run. A prolonged run at marathon pace is a good workout to perform at a very challenging level in the final weeks of preparation for a marathon, after you’ve established adequate raw endurance with long runs and longer progression runs featuring smaller amounts of marathon-pace running. 

Example: 2 miles at natural pace + 13.1 miles at marathon pace 

Intervals 

Interval workouts consist of repeated shorter segments of fast running separated by slow jogging “recoveries”. This format enables a runner to pack more fast running into a single workout than he or she could with a single prolonged fast effort to exhaustion. 

Interval workouts are typically subcategorized as short intervals and long intervals. Long intervals are 600-1200m segments run in the range of 5K race pace with easy jogging recoveries between them.  They’re an excellent means of progressively developing efficiency and fatigue resistance at fast running speeds. 

Example: 1 mile of easy jogging (warm-up) + 5 x 1 km at 5K race pace with 400m jogging recoveries + 1 mile of easy jogging (cool-down) 

Short intervals are 100-400m segments run at roughly 1,500m race pace or faster. They boost speed, running economy, fatigue resistance at fast speeds and pain tolerance. Distance runners typically use shorter, faster intervals earlier in the training cycle to increase their pure speed and then move to slightly longer, slower (but still very fast) speed intervals to add fatigue resistance to their speed. 

Example: 1 mile of easy jogging (warm-up) + 10 x 300m at 800m race pace with 400m jogging recoveries + 1 mile of easy jogging (cool-down)