It’s not just the length of the effort that counts. The length of your rest determines the purpose of the workout.
We know you put a lot of thought into your interval workouts: how far, how many, how fast. The interval recovery (or interval rest) portion of your workout may be merely an afterthought, but perhaps you should consider it more carefully.
Rest is an important variable to take into account when designing appropriately challenging, race-specific workouts. Manipulating the amount of rest in a given workout changes the benefits gained and physiological systems targeted. Tweaking the time taken between intervals can greatly modify the overall intensity of a workout, so you need to put as much thought into the rest periods between your intervals as you do the hard running.
In general, shorter rest periods ramp up the intensity of a workout because recovery is incomplete, and your heart rate remains high when the next interval begins.
“Typically, no matter what distance you are training for, you use short rest to keep quality up in a workout and your heart rate high. In addition, short rests can be utilized to break up a tempo workout and allow an athlete to run a fair amount of volume yet maintain intensity,” says Benita Willis, three-time Australian National Champion in the Women’s 5,000 meters, now coaching with Hudson Training Systems.
Willis advises using longer rests in workouts consisting either of very long intervals or very demanding intervals. “Longer rest periods when used training for shorter races are most beneficial so you can run a repetition almost flat out, then recover fully before you begin the remainder of the workout,” she says. “Quality is the focus here, not quantity.” In general, the more taxing the interval is, the faster it is, the more recovery called for.
Workouts with medium-length rests are a middle ground, where you can practice race pace yet also maintain it for a considerable amount of time.To help you get the hang of it, here are three interval workouts for three target distances with varying amounts of rest: short, medium, and long. Research has shown that active rest (jogging or walking) is more effective at clearing lactate and preparing you for the next repeat than standing, but listen to your own body, and do what feels best.
Interval Workouts for 5K
The workout: 3 x (4 x 400m) at approximately 3 seconds faster per lap than 5K pace (somewhere between 1500m and 3,000m pace), with 30 seconds between each 400 and a lap jog between sets.
Why it helps: Short rests between hard, fast intervals help teach the nervous system to adjust to faster running, promote stride power and efficiency, and allow you to practice maintaining form and speed when fatigued. Willis explains, “You use short rest in between hard, short intervals to generate some lactic acid in your legs, then practice running with heavy legs to increase your lactate threshold. This helps for the finish of a 5K .”
When you should do it: Do this workout in the month preceding an important racing block, when you’re looking to peak in a series of races.
The workout: 8 x 1,000m at slightly faster than 10K pace, with 60 to 90 seconds rest.
Why it helps: This workout promotes, develops, and supports the specific endurance necessary for racing a hard 5K. Willis defines specific endurance as the ability to resist fatigue at goal pace and complete the entire race distance at that pace. Keeping the rest at a medium duration lets you accumulate a substantial amount of volume but doesn’t afford a complete recovery, thereby encouraging optimal preparation for a goal race.
When you should do it: Do this workout approximately six weeks before a target 5K race, when the focus begins to switch from more general fitness to race-specific fitness and the ability to maintain pace for the duration of a goal race.
The workout: 3K at 10K pace or faster, 5:00 recovery, then 4 x 200m fast yet relaxed.
Why it helps: As mentioned before, longer rest periods allow you to complete an interval almost all-out, yet recover fully before beginning additional repeats. Quality is the focus here, not quantity. The 200s are performed at close to maximal speed.
When you should do it: Use this workout sparingly in early or mid-season. Willis explains, “Most distance athletes cannot handle more than four to five of these types of intense workouts because they generally take longer to recover from than tempo runs or intervals with a medium rest, so you need to carefully consider when to run a workout like this. A shorter, harder race can also take the place of a workout like this.”
Interval Workouts for Half Marathon
The workout: 10 x 800m at half marathon goal pace, with 1:00 rest.
Why it helps: Nicole Hunt, two-time Olympic trials marathon qualifier and coach, has athletes do this workout so that they obtain volume and intensity and practice running goal race pace. However, the recovery periods ensure that the workout isn’t too taxing physically or mentally, especially compared to, say, an 8 Km tempo run early in a training cycle.
When you should do it: It’s desirable to do this workout at the beginning of a half marathon cycle, when fitness is just developing, as it serves as an introduction to running at goal pace. The intervals are short enough that you can sample goal pace in an amount that isn’t overwhelming at such an early stage, yet benefit physiologically because the rest is kept so short.
The workout: 3 x 3 Km’s at goal half marathon pace, with 2:00 rest.
Why it helps: The goal of this workout is to practice longer bouts at goal pace. Hunt explains, “As the athlete progresses through the season the rest interval may decrease and/or the running interval increase, to optimally simulate race conditions.”
When you should do it: Do this workout midway through a half marathon cycle, when fitness is somewhat established and you can handle increasing distances at goal half marathon pace.
The workout: 2 x 4.5 Km’s at goal half marathon pace, with 4:00 to 5:00 rest.
Why it helps: Hunt explains, “As the running interval increases, more rest is necessary for recovery and to enable the athlete to run goal pace for a longer amount of time.” Doing 10 Km’s at goal pace in this manner should increase your ability to lock into pace on race day and stay mentally focused.
When you should do it: Do this workout in the final few weeks before a half marathon, as it’s fairly taxing and requires a high level of race-specific fitness.
Interval Workouts for Marathon
The workout: 6 to 8 x 1.5 Km runs at slightly faster than marathon pace, with 1:00 rest; or a 60-minute run broken into four 15-minute runs at slightly faster than marathon pace with a minute jog in between.
Why it helps: This workout allows you to keep the quality up and your heart rate high, but the small rest makes it palatable and not overwhelming. “You can use short recoveries to break up tempo runs to keep up the quality. You want to keep your heart rate high but not lose intensity, so sometimes it is helpful to give brief rest periods to achieve both,” says Willis.
When you should do it: Three to six weeks out from a goal marathon is the best time to complete this workout, as it’s fairly strenuous and requires a high level of fitness and general marathon preparedness.
The workout: 12 x 1,000m at faster than half marathon pace, with 1:30 to 2:00 rest.
Why it helps: Willis explains, “The purpose of this workout is to have the athlete get used to the feeling of running a lot faster than marathon pace for a long period of time. This is beneficial because when the athlete gets into the actual marathon, they will feel that the pace is ‘slow’ after completing these workouts. Their running economy and efficiency at marathon speed will be increased, and they should be more comfortable maintaining their marathon pace longer and ultimately finish faster.”
When you should do it: “This workout is great if used toward the start of marathon prep, particularly in the first month of a typical eight-week buildup,” says Willis. “You just want to make sure the athlete has a few easy days after it, as it is a little harder to recover from than some workouts due to both its volume and intensity.”
The workout: 10 x 1:00 hills, with jog down recovery in approximately 3:00.
Why it helps: This is done in the middle of a block between two hard marathon-specific workouts (i.e., a few days after the first one and a few days before the next one). It’s designed to get your legs moving fast but with plenty of recovery. Willis says, “This is good to do in marathon training sometimes without the risk of getting tired, but to get the benefit of fast leg turnover and hill strength. This is useful for the athlete to be training fast sometimes and not just be slugging out the K’s. You need to do some things in marathon training which will be much faster than goal race pace. Longer rest is needed to obtain this quality and recruit muscle fibres to maintain the feeling of running faster during higher Km weeks.”
When you should do it: Willis recommends doing this workout in any really hard, high-volume marathon training week. It’s designed to be a low-volume workout from which you can recover quickly, yet work on power and speed development.