Track Intervals Explained
When one Googles “Spartan Soldiers Running Really Fast”
Lately, it seems like a large majority of my 1-on-1 athletes are taking an interest in distance events. Marathons, 50-Ks, hell…even our Long and Strong training team spent the past several weeks working towards a timed 5-mile run as part of our new Fitness Aptitude Test (FAT).
That being the case, I feel that from a coaching standpoint, I have spent more time than usual lately digging into the theory behind different interval structures as a way of optimizing training towards those specific distance goals.
Three Amigos: Ascending, Descending, and Straight Intervals
While the dark arts of interval structures present myriad ways of setting up various distances and work:rest ratios, I felt that in writing some of this down for our readers, it would make sense to focus on three specific setups and the thought processes behind why you might choose one over the other.
The three that we will focus on are Ascending Intervals, Descending Intervals, and Straight (or Straight Set) Intervals.
Straight Set Intervals
Straight Set Intervals are exactly what they sound like: the same distance, repeated multiple times, straight across.
Example: 6x800m with a 1:1 work:rest ratio
In this example, the athlete would run 800m and rest for exactly how long it took to complete the preceding interval. For what it’s worth, a 1:1 work:rest ratio is a sort of “classic” aerobic prescription that we may dig into in a future post.
Purpose
Given that the athlete is completing multiple reps at the same distance and pace, the goal with Straight Set intervals is to train pace familiarization with that specific effort level. For those same reasons, a Straight Set workout also helps to build specific endurance for the prescribed pace as well.
Physiologically, intervals on the longer end of the spectrum (800m+) can be used to train aerobic development, whereas shorter intervals (<400m) can be used to train lactate tolerance and Vo2max improvement.
When to Use
All intervals can do all things at all times, but for this specific set up we’re thinking of three main things:
Goal race prep (ex. 5k pacing)
To measure progress (i.e. compare like workouts across multiple weeks)
To teach pace discipline (measured through the athlete’s ability to repeat output across multiple reps)
Ascending Intervals
Unlike Straight Set intervals, Ascending Intervals consist of increased distances from one rep to the next. We typically keep the same 1:1 work:rest ratio concept; however, because the distances (and thus work) increase, so too does the rest time from one interval to the next.
Example: 200m, 400m, 600m, 800m, resting 1:1 between each
In this example, the athlete would run 200m and then rest for as long as that interval took to complete. Following their rest, they would run a 400m, rest, a 600m, rest, and then an 800m.
Purpose
As reps get longer, we’re looking to develop aerobic strength and mental resilience in the athlete. Pushing hard on an interval while knowing that the work to follow is only increasing definitely plays on the psychological side of training. For those reasons, an Ascending Interval structure also promotes pace control and patience, introducing some gamesmanship and athlete autonomy to how the workout is approached. Physiologically, the increased time under tension leads to an increase in fatigue as well, allowing us to determine how well or how poorly the athlete can sustain a specific pace as they onboard more fatigue.
When to Use
Ascending Intervals can be a challenging workout for most athletes, so use them wisely in the following scenarios:
Whenever an aerobic “strength-building” stimulus is needed
To prepare athletes for longer intervals planned later in the phase
When athletes need to be able to perform specific paces under considerable fatigue (i.e. when a run is at the end of a PT Test)
Descending Intervals
Given that the Ascending Intervals consist of increasing distances from set-to-set, it should come as no surprise that in a Descending Interval workout, we are pursuing the opposite: descending distances from one interval to the next.
Example: 800m, 600m, 400m, 200m, resting 1:1 between each
In this example, the athlete would run 800m and then rest for as long as that interval took to complete. Following their rest, they would run a 600m, rest, a 400m, rest, and then a 200m.
Purpose
As the reps get shorter, we’re teaching the athlete how to speed up for a fast finish. Similar to a resistance training workout, this type of setup also helps to promote neuromuscular efficiency as the reps get shorter and faster. Physiologically, the athlete is shifting gears from more of an aerobic (i.e. oxygen delivery) stimulus to more of an “anaerobic” (i.e. oxygen utilization) stimulus, which helps to promote speed endurance and the ability to recruit more muscle fibers.
When to Use
Psychologically, Descending Sets seem to sit a bit easier with athletes due to the decreasing distances from one set to the next. That said, they still serve a valuable purpose in the following scenarios:
When working on form (especially faster form) under fatigue
To sharpen and/or taper for an event
To prepare an athlete for shorter, faster (and harder) straight sets later in a training phase
Summary
As I mentioned earlier in this article, there are many, many ways of setting up intervals to achieve certain goals within a training phase or in preparation for a specific event. It should also go without saying that the interval structure that you choose should be specific for a particular athlete. Think of intervals in the same way that you might think of weight training: for some, heavier weights at lower volumes (i.e. faster, shorter distances) might be appropriate for increasing strength, whereas for others, lighter weights at higher volumes (i.e. longer, slower distances) might make sense.
Play around with these different structures and see how they make you feel, both within the given session but also in the days and training sessions to follow. Make note of what you’re trying to achieve and whether or not it makes sense to repeat the same distances multiple times, increase distances (and fatigue) as you go, or decrease distances (and increase speed) from one rep to the next.