By combining high intensity interval training (HIIT) with small group training and an express workout format, the latest program from group exercise leaders LES MILLS can help you capture some of the 50 per cent of members who don’t currently engage in personal training or group exercise classes, says Marie Anagnostis.

When I sat down to write this article about GRIT™STRENGTH, the new small group training workout from LES MILLS, I couldn’t get the question ‘why?’ out of my head. Not ‘why am I writing this article?’, but ‘why has LES MILLS created a new program?’ Don’t we already have 10 of them? After pondering it for a while, I realised that the core of why we exist as a business frames the answer: to get more people moving ‘for a fitter planet’.

More people moving in your facility

So, how do you get more people moving in your facility? How do you keep them coming back every week? And how do you keep them from leaving?

Here are the facts:

  • The best facilities in the world engage up to 10 per cent of their member-base in personal training and up to 40 per cent in group exercise – begging the question ‘what’s happening with that other 50 per cent?’
  • 90 per cent of people prefer to work out in groups.
  • Members that attend group fitness attend their facility three times more frequently than those who work out alone and refer three times as often.

These facts suggest that getting more of your members to work out in groups will result in them coming back – and staying – while also telling their friends about your business. In club speak that’s attendance, retention, sales.

The GRIT™STRENGTH safety net

Which brings me back to the original question, why do we need another LES MILLS program to achieve these benefits? GRIT™STRENGTH is a new genre for LES MILLS: small group training (up to 20 people) led by a Captain. Not only does the program get members' results – and fast – it also serves as a ‘safety net’ to capture some of those 50 per cent of members who either can’t afford personal training or are reluctant to add more traditional group fitness to their training regime.

Capitalising on the popularity of high intensity interval training (HIIT), small group training and express workout formats (such as CrossFit and P90X), GRIT™STRENGTH is a 30-minute session comprising power lifting and plyometric moves. Without interrupting your studio timetable you can run GRIT™STRENGTH anywhere you have space in your facility, PT zone, gym floor or squash court. And by employing a ‘user pays’ model you can add an additional revenue stream to your business.

Let’s talk about results

At the core of GRIT™ STRENGTH is high intensity interval training (HIIT) – repeated bouts of short to moderate duration exercise performed at an intensity that is greater than the anaerobic threshold (the point of physical intensity where the body moves from aerobic energy supplies to anaerobic).

As your members increase their fitness (particularly at high intensities), they improve their ability to use their aerobic energy system at higher intensities, meaning they can go harder for longer. The physiological benefits of HIIT include:
EPOC (Exercise Post Oxygen Consumption)

Also known as afterburn, EPOC refers to the elevation of metabolism after the completion of exercise, necessary for returning the body to a normal resting state. This elevation of energy expenditure contributes to the total amount of calories that are burnt as a result of the training session. Intensity has been found to be the most important factor when it comes to producing an EPOC effect: the higher the intensity the more caloric expenditure needed after the exercise to return the body to normal.

Type 2 muscle fibre activation

We have two types of muscle fibres – fast and slow twitch. The slow twitch fibres are known as type 1 while the fast twitch are called type 2. Slow twitch fibres use oxygen for fuel, using the aerobic energy system, whereas fast twitch fibres work anaerobically (without oxygen). Each muscle has a mix of fast and slow twitch fibres, with a common ratio being around 40 per cent fast and 60 per cent slow. Steady state training uses predominantly slow twitch muscle activation – meaning that if we constantly train at lower intensities we only ever recruit 60 per cent of our available muscle fibre. High intensity interval training accesses the type 2 fibres in addition to the type 1 – enabling an increase in fibre recruitment of up to 40 per cent.

Fat loss

Research has demonstrated that a higher percentage of fat is used by the body during low to moderate intensity exercise – commonly known as ‘the fat burning zone’. However, while the percentage of fat utilisation is known to be higher during low to moderate intensity exercise, the total energy consumed is much greater during high intensity exercise. Therefore, the total calorie consumption from fat is typically equal or greater during shorter burst high intensity compared to longer low to moderate intensity exercise. Fat is also utilised during the EPOC phase for recovery – which we know is higher after high intensity exercise (up to nine hours after). High intensity exercise can be seen, therefore, to be an effective tool for fat loss.

Hormonal response

Any exercise that recruits multiple large muscle groups with brief bursts of high intensity efforts and restricted rest periods will elevate lactic acid levels. Lactic acid production is associated with an acute increase in human growth hormone levels. Human growth hormone stimulates muscle protein synthesis, and promotes the oxidation of fat – therefore increasing lean muscle and reducing body fat.

GRIT™STRENGTH has recently started rolling out in facilities across Australia. For information on training modules and adding LES MILLs’ latest program to your club, email or call 02 6215 8144.

Marie Anagnostis
A BODYATTACK®, BODYPUMP®, CXWORX® and GRIT™STRENGTH instructor, and personal trainer, Marie is passionate about the fitness industry. In her role of marketing and communications manager for Les Mills Asia Pacific, she combines her love of group exercise with her desire to spread the word about its benefits. For more information email