The Importance of an Aerobic Threshold Run

An aerobic threshold run is a longer run performed at a moderate pace that many distance runners often overlook, but it might just be the key ingredient for your future running success. It begins at an easy cadence and develops into a rhythmic pace in the middle before finishing at a strong effort over the final extents of the run.

Many runners neglect to train within the range of paces that fall between their maintenance-run pace and their tempo pace. This range is known as the aerobic threshold and helps runners develop their aerobic fitness. Competitive runners usually incorporate a variety of paces into their weekly training programs, ranging anywhere from a slow trot to a race pace. If executed properly, this well-rounded approach will have runners primed for success on race day.

There are a lot of physical and mental benefits to an aerobic threshold run. The longer-than-normal distance with the solid effort in the last stretch develops a runner's ability to hammer through the latter stages of runs when energy and strength are typically at a premium. Over time, as they become more fit, runners will gain the strength and confidence needed to take down the competition on race day. Physiologically speaking, the benefits of an aerobic threshold run include:

• Increased number and size of mitochondria
• Increased aerobic enzyme activity
• Increased capillary network surrounding working muscles

In many respects, an aerobic threshold run is an old-school tough training run. It is not an all-out run, but rather it is performed at a fast enough pace to engage your attention without being so hard that you can't recover in time for your next training run. For our local post-collegiate athletes, we regularly schedule an aerobic threshold training session that consists of a longer-than-normal-distance run that emphasises a strong effort throughout the final stages of the run. The run is intentionally slightly longer than normal to ensure that athletes do not run too hard through the initial stages of the session. On our athletes' training calendars, we refer to the aerobic threshold day as a "midweek long run."

The midweek long run is the longest training run of the week, except for the traditional weekend long run, by approximately 15-30 minutes and is roughly 15% of the athlete's total weekly volume. We ask that the last 30-40 minutes of the midweek long run be done at about 80% effort of the athlete's current 5K race pace. This level of effort is hard enough to feel like you did a solid workout, but not so hard that you can't come back in a couple of days ready to do another solid workout.

Keep in mind that as an athlete's fitness improves over time, the pace of the aerobic threshold run will incrementally become faster. For example, if an athlete improved their 5K personal best from 16:00 to 15:30 (3.05/kilometre pace), the aerobic threshold training pace would be a 3.50/kilometre pace. We typically schedule our midweek long run either the day immediately before or immediately after our interval training day, so our aerobic threshold workout typically falls on a Wednesday. If you tend to do a long run on Sunday and intervals on Tuesday, I recommend scheduling the midweek long run on Wednesday.

To avoid injuries, runners should slowly integrate aerobic threshold runs into their weekly training regimen. It is recommended that runners begin by incorporating only 10 minutes of aerobic threshold training into the later stages of their summer "base-building" season. After establishing a solid foundation, runners should progressively increase the duration of their threshold runs by approximately 5-10 minutes each month, continuing through the end of the fall cross country season.

At that point, runners should be able to complete a 30-40 minute aerobic threshold run, and as they prepare for the outdoor track season, threshold training will help to further build their strength. For athletes who race in the 10K distance up through the full marathon, aerobic threshold workouts should be a staple in their training program throughout the year, especially during the last 8-12 weeks of a race preparation period.

In contrast, runners in the first few years of their running journey should only schedule one longer run each week. Running an easy long run and an aerobic threshold run in the same week will likely be too physically taxing for less experienced runners, thus putting them at higher risk of injury. That said, relatively inexperienced runners can still develop their aerobic fitness even by only running one long run a week. Ideally, these runners would start the year simply by covering a set distance. As their fitness develops, runners can incorporate more elements of aerobic threshold training into their weekly regimen.

At San Luis Obispo High School, the cross country team performs a weekly long run approximately 75-90 minutes long through the hills surrounding the city. To effectively target the athlete's aerobic threshold, a special emphasis is put on running the last 5-6 kilometres of the run at a strong pace. Over the years, runs like this have become one of the training cornerstones of their successful cross country program. Aerobic threshold training isn't a romantic or complex style of running. Instead, it is a simple "meat and potatoes" type of training that exemplifies the hard grunt work necessary for success as a competitive distance runner. Weeks upon weeks of aerobic threshold training will result in an aerobically fit athlete that has a much higher chance of being successful throughout their racing season.

To determine the distance and pace of an aerobic threshold run, apply the following guidelines:

For example, take a 16:00 5K runner that runs 110 kilometres per week (KPW):

Schedule the midweek long run either the day immediately before or immediately after the midweek interval day.