High Intensity Interval Training is also called Sprint Interval Training. These training methods involve short, intense bursts of activity. These are hot research topics at present. A recent paper on trained triathletes found large improvements in endurance following a two weeks of sprint training.
The training consisted of ten six-second sprints. Two times a week. The athletes also continued their normal patterns of activity. A control group did not do the sprints. Both groups did a timed 10K run and a “time to exhaustion” test on a stationary bicycle. Two weeks of very short burst sprints shows big improvement. The group that trained with very brief sprints improved their 10K time by 10%. Time to exhaustion did not change.
Most interestingly blood lactate did not accumulate as fast in HIT-trained athletes. Accumulation of blood lactate is one of the things that make you feel crappy when you are pushing yourself. Feeling crappy later than sooner is better. Usually. Maybe you will get through a WOD without feeling like your body is screaming at all.
Extremely short high intensity interval training also improves function in other ways. For example, it also improves insulin sensitivity. So there may be some long term benefit too.
What does High Intensity Interval Training mean for CrossFit?
What does this mean for CrossFit? CrossFit naturally includes a lot of high intensity interval training. Including sprints in your WODs may be a very good idea. Especially if you are not a great runner. If you are doing a 400m or longer run try doing some very short bursts. It might end up improving your WOD time if you do a WOD with running. Every repetition counts. And every second saved lets you do another rep. Babraj JA, Vollaard NB, Keast C, Guppy FM, Cottrell G, & Timmons JA (2009). Extremely short duration high intensity interval training substantially improves insulin action in young healthy males. BMC endocrine disorders, 9 PMID: 19175906