High-intensity interval training has revolutionised the way Australians approach fitness. The premise is simple: alternate short bursts of maximal effort with brief recovery periods. A typical HIIT session might last twenty to thirty minutes, yet the metabolic and cardiovascular benefits rival — and often exceed — those of much longer steady-state workouts. Here is what the research says and how you can put it into practice.
What Makes HIIT Different
Traditional cardio relies on sustained moderate effort. You might jog for forty-five minutes at a steady pace, keeping your heart rate in a comfortable zone. HIIT flips that model. You push hard for twenty to sixty seconds, then recover for a similar or slightly longer period, and repeat. The intensity spikes force your body to work anaerobically, recruiting fast-twitch muscle fibres and triggering adaptations that steady-state cardio alone does not produce.
EPOC: The Afterburn Effect
One of the most compelling reasons to try HIIT is excess post-exercise oxygen consumption, or EPOC. After an intense workout, your body continues to burn calories at an elevated rate as it restores oxygen levels, replenishes energy stores, and repairs muscle tissue. Studies have shown that EPOC can last for hours after a HIIT session, meaning you are still burning more calories while you shower, eat, or sit at your desk.
Time Efficiency
For busy professionals, parents, and anyone who struggles to find an hour for the gym, HIIT offers a solution. A well-designed twenty-minute HIIT session can deliver cardiovascular improvements comparable to an hour of moderate jogging. That does not mean HIIT replaces all other training — variety remains important — but it provides a powerful option when time is limited.
Metabolic Health
Research has linked HIIT to improved insulin sensitivity, better blood sugar control, and favourable changes in blood lipids. For those at risk of or managing type 2 diabetes or metabolic syndrome, HIIT can be a valuable tool. Always consult your healthcare provider before starting a new exercise program, especially if you have existing conditions.
Getting Started Safely
If you are new to HIIT, start with one or two sessions per week and allow adequate recovery between them. A typical beginner protocol might be thirty seconds of effort followed by ninety seconds of rest, repeated six to eight times. As your fitness improves, you can shorten rest periods or lengthen work intervals. At Terrough, our HIIT Cartel classes are designed to accommodate all levels with clear modifications from our instructors.
Ready to experience HIIT for yourself? Request a free pass and try a class at your nearest Terrough club. Our trainers will guide you through the session and help you find the right intensity for your current fitness level.