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GRIT: PRESCRIPTION FITNESS

EXERCISE– BUT WHAT TYPE AND HOW MUCH?

We all know that we should be exercising regularly. Our doctors tell us. The government tells us. Even

celebrities tell us. And yet, despite the copious amounts of literature expounding the dangers of

inactivity and its associated diseases, an astonishingly high number of us do not fulfill the

recommended guidelines for physical fitness.

And when we say ‘exercise’ – what should this entail? Will a brisk walk suffice or should we be

exhausting ourselves until we are gasping for air? The guidelines themselves have proved to be

unclear: In 2013 ACSM (American College of Sports Medicine) recommended that, to reduce the risk

of developing cardiovascular disease (CVD), we engage in an unspecified combination of moderate-

intensity and vigorous-intensity exercise 3-5 days per week. At present there is no clear prescription

for engaging in exercise of vigorous intensity vs. moderate intensity; a gap in the guidelines exists.

HIIT AND THE FIT AND ACTIVE

Recent research has revealed that HIIT (High Intensity Interval Training) is the key to getting fitter,

faster. Several studies, conducted with sedentary adults, have provided compelling evidence that HIIT

also significantly lowers the risk of developing CVD. However, to date no studies had clarified how this

type of training affects the already fit and active. The research team at Les Mills set out to investigate

what effect HIIT would have upon a fit and active population, using the formula of the LES MILLS

GRIT™ Series – 30 minute HIIT workouts that incorporate explosive plyometric and dynamic strength

exercises.

THE TEST

Two studies were conducted at The Pennsylvania State University under the guidance of Dr Jinger

Gottschall, a professor of Kinesiology. Each lasted a duration of six weeks. One study focused on 84

active adults who were already regular participants in Les Mills’ strength and cardiovascular group

fitness classes and the other on 18 female soccer players.

The group fitness study participants were split into two groups for comparison. Both

groups completed five hours of fitness classes per week: the first (high intensity)

protocol included two LES MILLS GRIT™ workouts per week alongside two

cardiovascular and two strength group fitness classes; the second (moderate intensity)

was comprised of three cardiovascular and two strength group fitness classes.

The female soccer players changed their offseason conditioning: seven hours of

traditional training were replaced with four hours of traditional soccer and strength

training, plus two LES MILLS GRIT™ workouts.

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THE RESULTS

The most startling outcome of the group fitness study was that HIIT reduced CVD risk factors in an

already active population with above average health statistics. These participants showed vast

improvements in lean body mass, glucose tolerance and maximal oxygen consumption.

With respect to the soccer study, it was the first of its kind to use female athletes, and thus we can

look to the results with a focus upon HIIT for women. When asked why they exercise, the prevailing

response from most women will reference weight loss. We know that the best way to turn your body

into an efficient fat-burning machine is to develop muscle mass – with the most familiar way to

increasing your muscle mass being to lift weights. However, it’s a common fact that women often

prioritize cardiovascular exercise and neglect resistance training. This may be from a fear of ‘bulking

up’, or from a belief that cardio is the best way to lose weight. LES MILLS GRIT™ Strength incorporates

full body exercises such as clean and presses, deadlifts, dead rows, upright rows and hang cleans with

loaded bars. - The focus is on short sharp bursts of high repetition, not pushing excessive weight. The

significant changes in body composition seen in our results are the consequence of developing lean

muscle without the need for heavy weights; we can conclude that the significant improvements in

strength - demonstrated by these results - would benefit females for long term weight management.

For a fit and active population, HIIT is extremely time efficient. In the soccer study, the players

decreased their training time by two hours per week and still experienced improvements in training

status. LES MILLS GRIT™ offered variety to their training – thus potentially reducing the risk of overuse

injuries which may be sustained from traditional conditioning e.g. distance running. While this

particular investigation focused upon soccer players, the research indicates that HIIT could be applied

to a number of competitive sports - offering a real prescription for maximizing competition

performance and minimizing training time.

A PRACTICAL SOLUTION

LES MILLS GRIT™ takes HIIT out of the lab and offers a safe, evidence-based, practical application for

high-intensity exercise. One of the most important features of HIIT is that, not only can it enable

people to break through a fitness plateau, but the nature of the training is such that you won’t

plateau. For those who already have a good base level of cardiovascular fitness and strength, HIIT will

enable you to keep getting fitter. For athletes, it can reduce training time and still improve

performance on the field. The message is clear: it’s not the volume but the intensity that makes the

change. Our combined studies prove that 30 minutes of LES MILLS GRIT™ performed at the

recommended frequency of twice a week, will create significant changes in your fitness and body

composition, lower the risk factors for CVD, and smash through your fitness plateau. Finally - you’ve

got your prescription, what are you waiting for?