Is speed work good for half marathon training?
Many runners use speed work in their training routines as a powerful training tool. When done properly speed work can help transform your performance and help you blast through running plateaus. Regular sprinting at maximum exertion over a short distance can be beneficial to your endurance.
This type of high intensity training (HIIT) enhances fast-twitch muscle fiber recruitment. Your body is made up of a diverse pool of muscle fibers, mixed between fast-twitch and slow-twitch fibers. The slow-twitch fibers are used mainly during steady endurance work, like long-distance running in half marathon training. The ability to better use your fast-twitch muscle fibers will be a big help when your slow-twitch fibers are fatigued. This becomes important nearing the end of a race.
Although there are tons of advantages to using sprints to develop enhanced muscular capacity, there are some downsides. Speedwork can put stress on the central nervous system. It involves a huge amount of signaling by the nervous system to get the optimal muscle contraction as quickly as possible. Half marathon training rarely stresses runners’ nervous system to such a high degree like this during base building work. Because the central nervous system controls everything, if there are problems, your performance is going to suffer. So you have to allow for a full and proper recovery. Any time you use sprints, you put the body under stress and it needs some time to recover. A big part of recovery happens in the nervous system, and your body uses a lot of energy to repair it.
You should never perform two sprint intensive workouts on back to back days. Although you may not feel sore after sprints that does not mean that your body is ready to train. Rule of thumb, if you’re sprinting hard enough during your speed work session, your body should only be able to endure one training session like that per week.
My sprinting sessions are usually 5 or 6 repetitions of 100 meters of all-out sprints. Followed by a slow walk back to the starting point as a way to catch my breath. If you are incorporating weight training, spaced apart from any sprinting or heavy weight lifting sessions several days apart.
Don’t overdo it. You may feel like Superman, that you can lift and do speed work and long distances on the same 24 hour period. Your body needs time to recover from the intensity you are putting it through. In the long run, you’ll thank me. When it comes to training at high intensities, less is definitely more. From a purely endurance mindset, you might be anxious to get out and try to do more. Sprint only one day a week, or maybe two at the very maximum. If you still feel like you need more sprints, you can wrap up your normal weight training or distance running with a short speed set at the end.
If you can gradually incorporate sprints into your workout routine I’m confident that you will see some great results in your half marathon and marathon training.