If you’ve been exposed to commercial gyms or fitness in some form over the last decade you’ve likely encountered the phrase High Intensity Interval Training (HIIT). Briefly, this is a style of cardiovascular training that alternates between periods of high exertion and periods of rest and recovery. The most popular HIIT protocols are characterised by what can be called incomplete rest/recovery periods. For example 30 seconds sprint to 30 seconds recovery or the famous Tabata protocol of 20 seconds on 10 seconds off for 8 rounds.
Whilst these are certainly effective, if maximum fat loss is your goal they are not your best option. Where the incomplete rest periods suffer is in not allowing you to properly tap into the right energy system and intensity to force the desired physical adaptations to take place.
It’s quite common to see proponents of popular HIIT juxtaposing images of elite sprinters with distance runners to express the superiority of brief but intense training over steady state cardiovascualr exercise. The problem with this comparison is the common incomplete rest scenario espoused by many trainers doesn’t reflect the way these athletes actually train. It’s a half truth.
Pursuing power, explosiveness and performance is what creates these lean and athletic physiques. If you’re performing HIIT as it is regularly described it will limit your ability to progress these attributes. Why? Largely because the cumulative cardiovascular fatigue means you end up performing several minutes of medium intensity intervals. Athletes like Olympic sprinters don’t train like this because they’re not interested in teaching their bodies to perform poor quality movement at a slower rate. Neither should you!
ENTER HIGH INTENSITY SPRINT INTERVALS
Properly performed sprint intervals will transform you much faster than more conventional forms of HIIT, even more so than medium or low intensity cardio. The main difference between sprint intervals and HIIT is a higher intensity work portion coupled with more complete recovery. Superficially this might seem like nit-picking but it’s really a case of the devil being in the details. As a very general starting point I like to see a 1:6 sprint:recovery ratio. Meaning for every 1 second of effort you’ll spend 6 recovering, neatly translating into:10 seconds:1 minute, 20 seconds: 2 minutes, 30 seconds: 3 minutes.
Quite paradoxically as you become able to exert more power you may need longer to recover. You’ll simply understand this if you walk 100m compared to sprinting it like someone pulled a gun. Which took longer to recover from?
As concerns the duration of the sprint itself, experience and available research suggest between 10-30 seconds are ideal. Beyond this point begins to move into a different energy system that we are not interested in directly targeting at this point.
I describe several methods for perfoming sprint intervals in the attached video but if you want to experience the full benefits I suggest checking out my Four Week Fat Loss and Conditioning Program. As a Mad March special this comes with a personalised nutrition program to ensure you are getting the results you're after. You can check that out here:
FOUR WEEK FAT LOSS & CONDITIONING