Speed Workouts for the Half Marathon

With speed workouts, half-marathon training begins to get more interesting. When we refer to speed training, we are talking about interval sessions, also called repeat workouts. Speed workouts require you to run multiple bouts of certain distances at high intensities with recovery between the fast segments. This type of training not only plays a role in prompting some of the important physiological changes we already discussed but also teaches your mind to handle harder work. While easy days are typically low-pressure, speed workouts require you to put your game face on, and discipline is one of many benefits garnered. While you may be able to complete an easy run the morning after a late night out on the town, if you want to get the most out of your speed work, you will need to eat a hearty dinner and hit the hay at a decent hour. For whatever you give up to optimally execute these workouts, the training will give back to you tenfold. Every speed workout you complete is like money in the bank when it comes to resources on which you can draw during the most difficult moments of the race.

Surprisingly, advanced runners often make the same mistakes that novices do in terms of speed training, namely, they neglect it. For instance, we have had runners come to us feeling stale after running several races in a year. Digging into these runners’ histories, we often find that they are running so many races that they have completely forgone speed training, spending all their time on long runs, tempo runs, and recovery. Along with flat workouts tend to come stagnated finishing times. That’s where we set them straight by guiding them through the Hansons Half-Marathon Method. Like the other types of workouts, speed training is an important part of constantly keeping your system on its toes, requiring it to adapt to workouts that vary in intensity and distance.

Many runners who train for the half-marathon distance have done speed work in the past. Therefore, convincing them that speed work is important is not as difficult as it can be with marathon runners, who tend to neglect it. That said, some folks go too far in the other direction, putting too much emphasis on speed work, which can result in injury. The lesson here is to remember that all training has a purpose and a place.

If you are new to half-marathoning and your past speed workouts have consisted of simply running some days slightly faster than others, you are in the majority. Luckily, the speed workouts we give you here can provide an introductory course on how to implement harder workouts. As you learn to properly implement speed workouts, your training will be transformed from perhaps a somewhat aimless approach to fitness to a guided plan of attack. These workouts can also help you predict what you might be capable of in your half-marathon. With the help of speed work, you can successfully run a shorter race, such as a 5K or 10K, and then plug that time into a race equivalency chart to determine your potential half-marathon time. Additionally, this work helps to highlight weak areas while there is still enough time to address and correct them.

Physiology of Speed Workouts

The greatest beneficiaries of speed training are the working muscles. With speed sessions, not only the slow-twitch fibers but also the intermediate fibers become maximally activated to provide aerobic energy. This forces the slow-twitch fibers to maximize their aerobic capacities, but it also trains the intermediate fibers to step in when the slow-twitch fibers become fatigued. As a result of better muscle coordination, running economy improves. Stimulated by everything from speed workouts to easy running, running economy is all about how efficiently your body utilizes oxygen at a certain pace. The better we can use oxygen, the farther and faster we can run.

The benefits of speed work include:

• maximal development of muscle fiber
• running economy improvement
• increased myoglobin
• improved anaerobic threshold
• triggering of increased glycogen storage

Another adaptation that occurs through speed work is the increased production of myoglobin. In fact, research tells us that the best way to develop myoglobin is through high-intensity running (above 80 percent VO₂max). Similar to the way hemoglobin carries oxygen to the blood, myoglobin helps transport oxygen to the muscles and then to the mitochondria. With its help, the increased demand for oxygen is met to match capillary delivery and the needs of the mitochondria. Exercise at higher intensities can also increase anaerobic threshold. Basically, the speed intervals provide a two-for-one ticket by developing the anaerobic threshold and VO₂max during the same workout. What’s more, because speed sessions include high-intensity running near 100 percent VO₂max (but not over), glycogen stores provide upwards of 90 percent of the energy, thus rapidly depleting them. This, in turn, forces the muscles to adapt and store more glycogen to be used later in workouts.

Speed Guidelines

You’ll notice that the speed segments in our plans are located toward the beginning of the training block, while later portions are devoted to more half-marathon-specific workouts. This may seem counterintuitive when considering our emphasis on building fitness from the bottom up. However, if speed workouts are executed at the right speeds, it makes sense to include them closer to the beginning of your training cycle. As in other workouts, correct pacing is essential. You will notice that partway through the program, speed work transitions to strength workouts. While runners often worry they will lose the speed gains they have worked so hard to attain, endurance runners (specifically those racing for 90 minutes or more) need not fear. Development of the elements we explain typically occurs at paces above 80 percent of VO₂max. With that said, the speed workouts are shorter intervals ideally at 95–98 percent. Strength workouts are closer to 80 percent but are much longer in duration. It is important to note that the speed workouts produce the gains, whereas the strength workouts maintain the gains.

When many coaches discuss speed training, they are referring to work that is done at 100 percent VO₂max. In reality, running at 100 percent VO₂max pace can be maintained for only 3–8 minutes. If you are a beginner, 3 minutes is likely more realistic, while an elite miler may be able to continue for close to 8 minutes. Running your speed workouts at or above 100 percent VO₂max, however, causes the structural muscles to begin to break down and forces your system to rely largely on anaerobic sources. This overstresses the anaerobic system and doesn’t allow for the positive aerobic adaptations you need to run a good half-marathon. Our program bases speed work on 5K and 10K goal times, races that both last much longer than 3–8 minutes. Rather than working at 100 percent VO₂max, you probably run these distances at 80–95 percent VO₂max. Unlike other plans, the Hansons Method instructs you to complete speed workouts at slightly less than 100 percent VO₂max pace in order to spur maximum physiological adaptations. Go faster, and gains are nullified and injuries are probable.

In addition to pace, the duration of the speed intervals is important. Optimal duration lies between 2 and 8 minutes. If it is too short, the amount of time spent at optimal intensity is minimized, and precious workout time is wasted; if it is too long, lactic acid builds up, and you are too tired to complete the workout at the desired pace. As a result, the length of speed intervals should be adjusted to your ability and experience levels. For example, a 400-meter repeat workout, with each interval lasting around 2 minutes, may be the perfect fit for a beginner. In contrast, the same workout may take an advanced runner 25 percent less time to complete each 400-meter repeat, therefore resulting in fewer benefits.

Recovery is another important part of speed sessions, providing the rest you need to complete another interval. Guidelines for recovery generally state that it should be between 50 and 100 percent of the repeat duration time. For instance, if the repeat is 2 minutes in duration, the recovery should be between 1 and 2 minutes. However, we tend to give beginners longer recovery time at the start of the speed sessions to sustain them throughout the entire workout. We assign recoveries by distance (e.g., 6 × 800 with 400 jog recovery). This usually fits the guidelines for recovery time, especially as the repeat distance increases. With the 12 × 400 meter workout, the recovery time is a little longer. Because it is usually the first speed workout in the segment, we want to ensure it can be completed. Plus it just works better to keep runners moving forward, jogging during the recovery; otherwise there is a tendency to stand around for a few minutes before starting the next repeat.

With further training, recovery can be shortened as an athlete becomes able to handle more work. When doing intervals, one can adjust either the amount of work being done or the amount of recovery allowed. The amount of work is in line with the mileage of the program, however, so we don’t want to alter that. But as you become fit, the interval paces may begin to feel easier. In that case, shortening the recovery will provide the same stimulus as earlier in the program. Be aware, however, of running too hard. This session is meant to focus on accumulating time within the desired intensity range, not leave you so tired you can’t put in a quality effort. If you run your repeats so hard that you aren’t able to jog during your recovery time, you are unlikely to be able to run the next interval at the desired pace. In the end, these speed sessions should total 3 miles of running at that higher intensity, in addition to the warm-up, cooldown, and recovery periods. If you can’t get through the intervals to hit 3 miles total, you’re running too hard for your abilities and thereby missing out on developing the specific adaptations discussed. That said, if you are a novice runner and completely new to speed workouts, it’s better to run only some of the workouts at correct pace than to not run them at all. There’s no problem with building up to the scheduled mileage, as needed.

The speed sessions that are utilized throughout the Hansons Half-Marathon Method are provided below. Typically, the schedules start with the lower-duration repeats (10–12 × 400 m) and work up to the longer-duration repeats (4 × 1200 m and 3 × 1600 m). Once the top of the ladder is reached (from the shortest-duration workouts to the longest-duration workouts), you are then free to do the workouts that fit best with your optimal development. Most exercise physiologists agree that this optimal development occurs with intervals that are 2–6 minutes in duration. Anything shorter doesn’t stress VO₂max enough, and anything longer tends to stress it too much, creating undue fatigue. So let that be your guide. If the 1600 workout is well above that 6-minute threshold, don’t use it. Keep your workouts in that 2–6 minute range per repeat.

For those new to speed work, we strongly encourage joining a local running group. Coaches and more experienced runners can take the guesswork and intimidation out of those first speed workouts by showing you the ropes. When a client tells me he or she has a running group that meets on a certain day during the week, I will do everything I can to schedule that into the training. Additionally, a local track will be your best friend during this phase because it is marked, consistent, and flat. If you are driven by numbers, you can even check your pace every 100 meters to give you nearly constant feedback. This means owning a watch is a must. While your pacing will likely require some trial and error at the beginning, the watch and marked track will help you keep your workouts at the right speeds until pacing becomes second nature. Find your goal pace for 5K or 10K and run the designated interval as close to that pace as possible. Remember, each session should include a 1- to 3-mile warm-up and cooldown.

Week 1 | 400 Repeats
12 × 400 with jog recovery for 50–100% of interval time

Week 2 | 600 Repeats
8 × 600 with jog recovery for 50–100% of interval time

Week 3 | 800 Repeats
6 × 800 with jog recovery for 50–100% of interval time

Week 4 | 1K Repeats
5 × 1K with jog recovery for 50–100% of interval time

Week 5 | 1200 Repeats
4 × 1200 with jog recovery for 50–100% of interval time

Week 6 | Ladder
400-800-1200-1600-1200-800-400 with jog recovery for 50–100% of interval time

Week 7 | 1600 Repeats
3 × 1600 with jog recovery for 50–100% of interval time

Adapted from Hansons Half-Marathon Method by Luke Humphrey with permission of VeloPress.

https://www.velopress.com/books/hansons-half-marathon-method/