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HIIT Q&A with Bryce Hastings


What is the difference between cross fit and GRIT? Can you do HIIT programs when pregnant? I get dizzy during high intensity training, why? On 26 July we had the pleasure of hosting Bryce Hastings* as part of a HIIT Q&A session on the Outside The Studio: HIIT closed Facebook group.

In case you missed it, here is a selection of the High Intensity Interval Training (HIIT) specific Questions and Answers, proposed by you, answered by Hastings:

Q. What are the best recovery strategies post HIIT class? How can you optimise the workout with recovery?

A. Separating your workouts is key. If you're going all out, two workouts a week seems to be optimal, this allows you to still include strength training and other cardio classes along with flexibility and core. The most common mistake I see is HIIT addiction: other training modalities are still really important and they help you recover. Remember every HIIT workout needs to be at max to deliver the effect.

Q. If I'm pregnant, can I participate in HIIT classes?

A. NO. HIIT is contraindicated during pregnancy – even the early stages. The whole point of HIIT is to hit sharp spikes. This is a no-no when pregnant.

Q. Are there HIIT principles in our other programs (such as BODYSTEP Athletic/Classic)? If so, how do they differ from GRIT and SPRINT and what are the benefits of this?

A. Our other programs are what we call cardio peak training where we hit a variety of cardio intensities – however we don’t see the sharp spikes of intensity we see in GRIT and SPRINT, therefore they deliver different training benefits.

Q. I'd like to think that I'm a pretty fit and healthy person but I often feel nauseous and dizzy after high intensity intervals. Is there any way to help this?

A. There are a lot of things to consider with this. Firstly nutrition is key and needs to be sorted when you do HIIT; this is very individual. Secondly I have come across high intensity induced migraines that are a real problem. There are lots of theories on why these occur from neck stability to vascular issues: nausea and dizziness may be part of this type of response. In short see a sports doctor if you are concerned.

Q. How do Les Mills HIIT programs (GRIT and SPRINT) compare to cross fit workouts?

A. The key difference is the second "I" in HIIT: Intervals. A lot of cross fit workouts don't separate work-blocks with intervals meaning people aren’t getting the sharp intensity spikes we see in HIIT. It’s those really steep sharp spikes that create the HIIT effect.

*ABOUT BRYCE: Bryce Hastings is the Group Fitness Research and Operations Manager for Les Mills International. Literally the brains behind the brawn, Bryce leads groundbreaking research and collaborates with internationally-renown research partners to unearth the latest and most effective fitness techniques. He strives to stay current on fitness research from a vast number of sources. Drawing from this research and his time in the fitness lab, Bryce ensures that every LES MILLS program is safe, effective and grounded in science.