High-intensity interval training has long had a reputation as one of the most time-efficient ways to burn fat. Research comparing it to steady-state cardio suggests HIIT is not necessarily more effective at burning fat overall, but it wins on two fronts that matter to most people: it takes far less time to get a similar result, and most people simply enjoy it more.
Why efficiency matters
If a 20-minute HIIT session burns roughly the same amount of energy as 60 minutes of steady cardio, the time saved speaks for itself. Add in the fact that interval training tends to be more engaging than a long, steady grind, and it becomes an easy choice for anyone short on time. It really comes down to a trade-off: keep the intensity low and the duration long, or push the intensity up and cut the duration down.
The 30-20-10 protocol
Researchers from Copenhagen set out to find the ideal split of low, moderate and high-intensity work within a HIIT session, testing the idea specifically with running across athletes, moderately trained people and non-exercisers. What they landed on became known as the 30-20-10 protocol: 30 seconds of low-intensity work, followed by 20 seconds of moderate effort, followed by 10 seconds at around 90 per cent of maximal effort. Repeating that sequence five times takes about five minutes, followed by a two-minute rest, for a total session of 15 to 20 minutes of work plus six to eight minutes of rest.
What the research found
The study involved runners who were already covering around 22 kilometres a week. After seven weeks following the 30-20-10 protocol, the group improved their 5 km time by up to a minute and saw reductions in blood pressure and cholesterol, compared with a control group who kept running their usual weekly distance without the interval structure.
Why this protocol works well for most people
A big part of the appeal is that the hardest phase only lasts 10 seconds, which is far more approachable than protocols asking for 20 seconds to several minutes of maximal effort. That makes it accessible for both beginners and experienced athletes. It also combines active recovery (the low-intensity phase) with genuine rest (the two-minute breaks), so the intensity stays sustainable across the whole session.
How to try the 30-20-10 protocol
This works on a treadmill, elliptical trainer or exercise bike. Here is the structure:
- Warm-up: 5 minutes walking or a slow jog.
- Phase 1: Repeat 5 times: 30 seconds low intensity, 20 seconds moderate intensity, 10 seconds high intensity.
- Rest: 2 minutes, no activity.
- Phase 2: Repeat 5 times: 30 seconds low intensity, 20 seconds moderate intensity, 10 seconds high intensity.
- For many people, two rounds is plenty. Want more of a challenge?
- Rest: 2 minutes, no activity.
- Phase 3: Repeat 5 times: 30 seconds low intensity, 20 seconds moderate intensity, 10 seconds high intensity.
Start with two rounds if you are new to interval training, and build up to three as your fitness improves.
Try it at Hammers Gym
Every piece of cardio equipment you need for this protocol is available at Hammers Gym, open 24/7. If you would like help structuring HIIT sessions like this into your program, our personal trainers can help.
Hammers Gym is in Nunawading, minutes from Mitcham, Blackburn, Box Hill and Doncaster. Try us with a free trial or view our membership options.
Reference: Gunnarsson TP, Bangsbo J. “The 10-20-30 Training Concept Improves Performance and Health Profile in Moderately Trained Runners.” Journal of Applied Physiology. 2012 Jul;113(1):16-24.