There’s no doubt that high-intensity interval training (HIIT) drives amazing results. Several studies, conducted with sedentary adults, provide compelling evidence that HIIT can rapidly build fitness. However, there’s been nothing to demonstrate how HIIT affects those of us who are already fit and active. Until now.
In two separate studies, Dr Jinger Gottschall and a team of researchers at Penn State University have proved that Les Mills’ HIIT programs can transform the fitness of regular exercisers.
The first study compared a group of adults doing regular LES MILLS™ group fitness classes for five hours a week with a group that substituted one of their hour-long cardio classes (such as BODYATTACK™, BODYSTEP™ or RPM™) with two LES MILLS GRIT™ workouts. Those who did LES MILLS GRIT™ showed vast improvements in lean body mass, glucose tolerance and maximal oxygen consumption. There was also a startling reduction in cardiovascular disease risk factors.
The second study followed professional female athletes. A team of soccer players substituted their usual seven hours of off-season training with just four hours and added two LES MILLS GRIT™ workouts. Despite decreasing their training time by two hours per week, the soccer players saw significant changes in both body composition and fitness levels.
Together these studies prove that 30 minutes of LES MILLS GRIT twice a week, will create significant changes in your fitness and body composition, lower the risk factors for cardiovascular disease, and smash through your fitness plateau. For a fit and active population, HIIT is extremely time efficient.
“For those people with a good base level of cardiovascular fitness and strength, HIIT will help you to keep getting fitter,” explains Bryce Hastings, Les Mills Head of Research. “For athletes, it can reduce training time and still improve performance.”
Bryce adds that the findings of this second study are not only relevant for soccer players. “It is a very real prescription for maximizing competition performance and minimizing training time across a range of competitive sports.” What’s more, the variety provided with LES MILLS GRIT workouts, could potentially reduce the risk of overuse injuries that can come from traditional conditioning such as distance running.
With this research front of mind the message is clear: it’s not the volume but the intensity that fuels change.
Two 30-minute LES MILLS GRIT sessions a week is all it takes. You’ve now got your prescription, what are you waiting for?
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