March 4, 2013 • Strength & Conditioning

Powerline: Exploring introductory intervals

The cold, blustery days of winter mark the offseason period for most fall sports, and also usher-in the strength and conditioning programs that are so vital to physical development.

Depending on the playoff or bowl picture for high schools and colleges, the strength training program begins as early as mid-January, with the speed, agility and conditioning procedures right on its heels.

In this installment, let’s take a closer look at some of the protocols we administer in our early offseason running program, when re-establishing an anaerobic baseline is so vital and one of our prime objectives.

The concept of introductory intervals

When you first embark on the offseason conditioning period, the key point of emphasis is to keep the intensity level in the low to moderate range. This is due to your athletes having been relatively dormant for several weeks. It’s not wise to rush into a full-speed sprint workout the first day out of the blocks.

It must be understood that any type of activity is probably going to result in delayed onset muscle soreness (DOMS), and since the soft tissue components (i.e., muscle, fascia, ligaments, tendons) need time to adapt to stress, a moderate phase-in period is advised.

We accomplish this with what we call “introductory intervals,” which are performed in “easy stride” and “fast stride” tempos. While those terms are subjective in nature, we take the time to define them as clearly as possible. Familiarity with how well the players can run — and how well they run with each other in their position groups — is a requisite.

Basically, easy strides are faster than a jog, and fast strides are faster than easy strides, but not quite all-out sprints. Give consideration to each position group:

  • Power is our offensive and defensive line group.
  • Big skill consists of our linebackers, tight ends, quarterbacks, fullbacks and specialists.
  • Skill refers to our wide receivers, defensive backs and tailbacks.

While the tempo is judged with an eyeball test, our players have learned what is expected and do a great job of adhering to the concept.

Here are a few examples of this format in action:

• Width accelerations: Starting on the sideline of a football field, an easy stride is performed to the near hash. A fast stride is then performed from the near hash through the far hash, at which point the athlete throttles-down to an easy stride to the far sideline. A respite of 20 seconds is given before the next interval. We start this protocol with eight to 10 intervals and build on a two-per-week basis up to 16 reps.

• Length accelerations: Starting at the goal line of a football field, an easy stride is performed to the near 40-yard line. At that point, the athlete kicks into a fast stride through the far 40-yard line, then decelerates to an easy stride through the far goal line. A relief interval of 20 to 30 seconds is given before the next bout. Again, we begin with eight to 10 reps and build gradually to 16 intervals at a rate of two per week.

• Ladder accelerations: This protocol goes from high-to-low in yardage requirements. Starting at the goal line, an easy stride is performed to the far goal line. A foot touch is performed on the goal line, followed immediately with a turn and a fast stride back to the starting line (200 yards total). After a respite of 30 seconds, an easy stride is performed to the far 10-yard line, a foot touch and turn is executed, followed by a fast stride back to the start (180 yards total). After another 30-second relief period, the process is repeated to the far 20-yard line and back (160 yards total). The ladder continues with a touch at each receding 10-yard mark until the entire field has been covered (i.e., the last interval is to the near 10-yard line and back, for 20 total yards).

The foot touching on each line (right or left) should be alternated with every interval. Also, the relief respites between runs are 30 seconds for the runs up to the 50-yard line, and 20 seconds for the runs to the near 40-yard line and to completion. After a couple of weeks, a second ladder can be inserted (note: allow a full three- to five-minute rest after the completion of the first ladder). Or, a “half-ladder” can be executed; starting with a run to the 50-yard line and regressing down the ladder from there.

• 300s: These are run on a track or the perimeter of a football field (running outside the sidelines on the straights, rounding the corners between the 5-yard line and goal line, and continuing through the end zones is approximately 300 yards). Our Power group is given a target of 60 to 65 seconds, the Big Skill group should be able to hit a 50- to 55-second target time, and the Skill group usually nails a 45- to 50-second target time. These target times essentially amount to a fast stride tempo for each independent position grouping. Of course, depending upon your specific sport and the level of athletes under your direction, modifications can and should be made. An initial workout of four repeats is normally executed with this protocol, with one interval added each week up to eight bouts. The recommended relief respite is twice the amount of time taken to complete the run. Once again, common sense is in effect here, especially with young, inexperienced athletes.

An educated eye should be firmly focused on the rate of perceived exertion, which is simply an objective discernment of how the athletes are handling the intensity of the workout.

Try rotating these four protocols on two non-consecutive days per week (i.e., use a different workout on each training day) for variety in the early stages of the running program. They are excellent introductory interval workouts for achieving the aforementioned physical adaptations required prior to full-speed agility and sprinting programs.

Gradually heighten the intensity

Four to five weeks of introductory, easy stride-fast routines prepare your athletes for higher intensity sprint and agility sessions. We still recommend, however, a conservative approach during this transitional phase. In other words, an all-out workout of 12 full-speed, 40-yard dashes on the first day of week four or five is ill-advised.

In our opinion, a more judicious approach is to implement a couple of timed, middle-distance interval protocols that push the athletes a notch or so above the fast-stride tempo for a couple of weeks.

Here are a couple of our favorites:

• 110s: This interval format starts on the end line at one end of the football field and is completed at the opposite goal line. The target times fall in the following ranges for each position group: Power: 18 to 20 seconds; Big skill: 16 to 18 seconds; Skill: 15 to 17 seconds.

The slower times are indicative of an easy-stride tempo and the faster times kick them into a fast-stride tempo. These are introduced in an eight- to 10-rep set and progressed at a rate of two reps per week up to 16 total reps. A 45- to 60-second relief interval is afforded between each bout.

• Half-gassers: Once across the football field and back constitutes a half-gasser. Starting on one sideline, the athlete runs to opposite sideline, executes a foot touch, then returns to the starting position. The target times, relief respites and rep progression mirror that of the 110s. As noted with the ladder protocol, the foot touches (right or left) are alternated with each rep.

Final rep

Upon completing an introductory interval program, your athletes have established a sound metabolic foundation with appropriate adaptations firmly set in their vascular systems and soft tissue compartments. They are properly prepared for higher-intensity sprint and agility protocols, a process that should reduce the likelihood or severity of muscle strains and other overuse issues.

As we have mentioned in past installments, it is critical that your higher-speed running and agility workouts include attention to detail regarding skill and position-specific movements.

One advantage of the introductory intervals is that once they are in the books, you can make a quicker, smoother transition to functional, high-speed, sport-specific training.


Ken Mannie is the head strength and conditioning coach Michigan State University. His column, Powerline, appears regularly in Coach & Athletic Director magazine. 


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