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High Intensity Interval Training - the GREAT, the NOT GREAT and WHY!

I LOVE High Intensity Interval Training (HIIT). It has transformed how I workout.. it shortened the length of my workouts and seriously increased my results.. not just physically getting me into the best SHAPE of my life, (good-bye body fat, hello muscle definition), but also my cardiovascular fitness and strength has never been better.

HIIT alternates between intense bursts of activity and peroiods of recovery.. It could be just what you need to boost your metabolism and shift unwanted body fat!

Before I go on I want to stress that High Intensity Interval Training (HIIT) is NOT for everyone!

1. HIIT MUST be worked up to, it is NEVER a good idea to start here. Your base fitness has to be established before jumping into intense training.

At HardCORE Fitness we have experienced members and total beginners at BOOTCAMP.. in our classes there is always an option to modify the exercise and pushing to maximum intensity is definitely NOT recommended for everyone there. Beginners need to work out at a comfortable pace, that is ENOUGH, that is FANTASTIC!! Doing too much too soon can cause excessive muscle soreness, which in extreme cases can cause rhabdomylosis (the break down of damaged muscle into the bloodstream which can cause kidney failure). That also goes for anyone who has had a break, whether on holiday or due to an injury and is returning to exercise. We can slowly progress towards increasing the intensity, and for some, increasing to max intensity may never be a viable option.

2. High blood pressure, dizziness, heart conditions, chronic pain, joint pain, and other medical issues MUST be discussed with a medical professional before considering HIIT training. It is a very demanding type of exercise on the body.

3. You need a STRONG FUNCTIONING CORE to perform intense workouts SAFELY.

There is a greater risk of injuries when we work out at an intense pace, especially if our core is weak and we are unable to maintain good form.

If you have BACK PAIN, ANY PELVIC FLOOR ISSUES (including leaking), or an unhealed ab separation HIIT is not going to be helpful, and will likely exacerbate the issues. Postpartum, I don't recommend HIIT until you are completely symptom free. Our core has gone through some pretty big changes and we need to allow it time to heal. There is a risk that jumping into this kind of training too soon, even if we haven't been experiencing any symptoms beforehand, can cause problems.

We always have the option to modify exercises, we always have the option to choose LOW IMPACT. HIIT training doesn't have to be jumping and running.. we can still get high intensity out of a low impact workout.

- Low impact training is obviously much kinder on our joints and is the safer option when recovering from injuries or still working up our base fitness/core strength.


When you are physically able to take part in HIIT, maintaining good form and not holding your breath, the benefits can be pretty incredible!

- Boosting metabolism, increasing our AFTER BURN.

After a HIIT workout our body continues to burn calories long after we have stopped. The metabolism remains boosted for hours, and sometimes even days, after an intense workout. This is where I prefer HIIT training over steady-state (keeping the same manageable pace) when it comes to fat loss.

- Very effective for BODY FAT LOSS

HIIT training burns fat, but sculpts and maintains lean muscle. (Think about how a marathon runners body usually looks lean but softer and how a sprinters body is usually lean and well defined muscle).

I have done, and taught, many different training styles over the last 15 years but I have seen the most impressive results for lowering body fat with HIIT training.

- TIME EFFICIENT WORKOUTS (great for busy people)

HIIT workouts need to be short to allow for maximum intensity (our body can't keep going that intensely for long!) Yes we have to work out HARDER to gain the benefits of the after burn, but the shorter time required can be a pretty worthwhile trade off!


Mixing bursts of intensity with recovery periods is a great way to boost mood and keep workouts interesting and FUN!

It is important not to over do HIIT training. Our body needs time to rest and recover in between! If you are feeling exhausted, REST. You may need to build more rest days in to your workout plan.

An example of a challenging HIGH IMPACT HIIT workout, 10 sets of 10 turning burpees.

- There are many modifications we could do to this workout to make it more achievable, including making it a low impact version.


and see four modifications of a burpee.


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