Network Magazine Spring 2019 | Page 44

How many interval workouts per week and per program? For the goals of health and body composition, HIIT sessions are recommended to be performed twice per week. For performance, a twice-a-week approach might be used initially, however, recent data suggest that a block periodised organisation of training might be more beneficial. Here, interval sessions would be performed each day of the week to overload the fitness capacity of the individual. This ‘hell week’ would then be followed by three lighter weeks, where one HIIT session would be performed each week. Due to the intensive nature of this 4-week block method, it is only recommended for serious endurance athletes. Training-nutrition interaction and the train low philosophy Since the recent advent of techniques able to measure the molecular response to exercise, scientists have discovered that performing HIIT with differing amounts of carbohydrate stored in the muscle can alter the physiological response to the session. These discoveries have led to a paradigm of training and nutrition called Train Low in which sessions are either deliberately conducted with low carbohydrate stores in the muscle; with normal carbohydrate levels but with carbohydrate-deficient meals consumed afterwards; or in the afternoon followed by a low carbohydrate dinner and going to bed with low muscle glycogen (recover low and sleep low respectively). This change in thinking around fuelling for training is based on numerous studies showing greater muscle adaptation to sessions performed when the working muscles are deprived of carbohydrate during or after training. This makes sense, as training is stress and training without a major muscle fuel is even greater stress. Of course, these recommendations are for training blocks and not for performance, as it is beyond dispute that performance is enhanced with adequate glycogen stores. Wrapping up HIIT HIIT can improve your health, body composition and performance. In some instances, it is more time effective than traditional endurance exercise, while still imparting the benefits of longer duration, higher volume sessions. HIIT can be broadly categorised into three subtypes: 44 | NETWORK SPRING 2019 sprint intervals, in which the sprints are performed at your best ‘all-out’ pace with almost full recovery; short intervals; and long intervals, both of which are performed around your best sustained aerobic pace or power. Workouts are typically performed twice a week using a mode of exercise that can handle high work outputs without fear of technical failure. With the majority of the population having enormous demands on their time, finding the opportunity to exercise can be difficult. For those that can manage the intense nature of the bouts, HIIT has become an extremely attractive option, as the time commitment is low and the benefits are huge. REFERENCES Gibala, G. (2017). The One Minute Workout. Vermilion: London. Laursen, P. & Bucheit, M. (2019). Science and Application of High-Intensity Interval Training. Human Kinetics: Champaign, Il. Rønnestad BR, Hansen J, Thyli V, Bakken TA, Sandbakk Ø. 5-week block periodization increases aerobic power in elite cross-country skiers. Scand J Med Sci Sports. 2016 Feb;26(2):140-6.  Tabata I. et al. Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max. Med Sci Sports Exerc. 1996 Oct;28(10):1327-30. Tony Boutagy Tony has been a trainer for 25 years, specialising in the development of strength and endurance, and training for body composition. He holds a PhD in Exercise Science and is an Accredited Exercise Physiologist (ESSA). Tony runs educational courses for personal trainers in his Sydney-based facility.