Dylan Abigail 
High intensity interval training has become one of the most popular approaches to fitness in Singapore, with many people recognising its ability to deliver powerful results in a short time. A structured hiit training workout is not the same as just alternating sprints and rests. There are multiple interval methods in the fitness world, such as Tabata, Fartlek, sprint intervals, and EMOM (every minute on the minute). Each method carries unique characteristics, and understanding the differences helps you make informed choices about your own training journey.
The Core Principles of Interval Training
Interval training broadly refers to alternating periods of work and rest. This principle can be applied across various activities, from running to cycling to bodyweight drills. However, intensity, work-to-rest ratios, and overall programme structure vary greatly depending on the method. Some are better suited to cardiovascular endurance, while others drive power and speed or focus on metabolic conditioning.
Key principles include:
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Intensity variation: Short bursts of near-maximal effort followed by recovery.
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Energy system engagement: Switching between anaerobic and aerobic pathways.
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Progressive overload: Gradually increasing intensity or duration over time.
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Adaptability: Customising exercises for different fitness levels.
Understanding these foundations helps you see why HIIT, and particularly structured programmes like Les Mills GRIT HIIT, stand out from more generic approaches.
Traditional HIIT Explained
HIIT is designed to push your heart rate into high zones during short intervals, often 20 seconds to 1 minute, followed by rest or active recovery. The benefits include increased calorie burn, improved VO2 max, and stronger metabolic conditioning. It triggers what scientists call excess post-exercise oxygen consumption (EPOC), which means your body continues burning calories after the workout is over.
HIIT often includes a combination of explosive bodyweight movements, weighted exercises, and sprints. It is highly effective, but if not structured correctly, people may overtrain or under-recover. This is why guided HIIT programmes bring extra value, offering progression and science-backed sequences.
Comparing HIIT to Tabata
Tabata originated in Japan and follows a strict format: 20 seconds of all-out effort followed by 10 seconds of rest, repeated for 4 minutes. It is simple, fast, and extremely taxing. While it builds both aerobic and anaerobic endurance, its limited time frame may not offer the same strength or skill development as a longer HIIT session. Tabata is best viewed as a quick, supplementary workout rather than a complete training plan.
Fartlek Training: The Playful Approach
Fartlek, meaning “speed play” in Swedish, blends continuous running with random sprints. Unlike HIIT, which is structured, Fartlek is less rigid and often relies on natural landmarks or timed surges. It is great for endurance athletes who want to develop pacing skills while keeping workouts less monotonous. However, for people seeking body composition changes or strength improvement, Fartlek alone may not be sufficient. It lacks the resistance and strength component that HIIT incorporates.
Sprint Interval Training (SIT)
Sprint interval training involves maximum effort sprints lasting 20 to 60 seconds, followed by long recovery periods of 2 to 4 minutes. It pushes the anaerobic system to its limit, leading to rapid improvements in sprint performance and VO2 max. However, SIT is demanding on the nervous system and joints, making it less sustainable as a daily or weekly practice. HIIT, with more moderate work-to-rest ratios, is often safer for long-term adoption.
EMOM: Every Minute on the Minute
EMOM is a time-based structure where you complete a set number of reps at the start of each minute, using the remaining time for rest. For example, you may do 10 push-ups and 10 squats within 40 seconds, then rest 20 seconds until the next minute begins. EMOM is excellent for building muscular endurance and work capacity, but it can sometimes compromise form as fatigue builds. While it brings discipline and pace, it may not deliver the same cardiovascular benefits as HIIT.
Why Les Mills GRIT HIIT Stands Out
Les Mills GRIT HIIT is not just another workout trend. It combines the principles of HIIT with sports science research, curated music, and structured progressions. Each session is designed to maximise effort in a safe, effective format. Unlike freestyle HIIT, GRIT HIIT uses carefully chosen work-to-rest ratios, integrated strength and cardio blocks, and a motivational group environment to enhance adherence and results.
Highlights of GRIT HIIT include:
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Varied formats: Strength-based, cardio-focused, or mixed conditioning.
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Science-backed programming: Periodisation ensures progression without burnout.
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Group motivation: Energy of a class keeps you accountable.
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Efficient duration: 30 minutes that deliver maximum impact.
The key advantage is balance. You get the metabolic effects of HIIT while building functional strength and movement quality, something many other interval methods lack.
Physiological Differences Across Methods
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HIIT: Balanced mix of aerobic and anaerobic engagement, sustainable for long-term use.
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Tabata: High intensity but short in duration, best as a finisher.
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Fartlek: Focused on aerobic capacity and endurance, less strength impact.
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SIT: Maximal effort with long recovery, excellent for athletic power.
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EMOM: Strength and muscular endurance oriented, less cardio-centric.
By comparing these, you can see why HIIT, and specifically Les Mills GRIT HIIT, is considered more well-rounded. It merges the best aspects while minimising risks of overuse or imbalance.
Practical Advice for Choosing Your Method
When deciding which interval method to adopt, consider your goals:
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If your aim is weight loss and general fitness, HIIT or GRIT HIIT are excellent choices.
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For athletes needing speed and endurance, Fartlek or SIT may provide sharper results.
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If you want discipline in strength training, EMOM offers structure.
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For short bursts of intensity with minimal time, Tabata is effective.
The beauty of GRIT HIIT is that it suits everyday people as well as athletes, offering progression that adapts to different needs.
The Role of Professional Guidance
It is worth remembering that guidance improves results and reduces injury risk. Certified instructors can help with form correction, intensity monitoring, and motivation. At True Fitness Singapore, members benefit from access to such structured programmes in a supportive environment, ensuring safety and consistency.
Frequently Asked Questions
Q. Can I combine HIIT with other interval methods in the same training week?
A. Yes, but it should be programmed carefully. For example, you may use HIIT twice a week and add one Fartlek session for variety. Ensure you have enough recovery days to avoid overtraining.
Q. How do I know if I am working hard enough during HIIT?
A. A good measure is the rate of perceived exertion (RPE). Aim for 8 or 9 out of 10 during work intervals. Alternatively, monitor your heart rate. You should be hitting 80 to 90 percent of your maximum heart rate.
Q. Is HIIT safe for beginners?
A. It can be, provided the workout is scaled. Beginners can use lower impact moves, longer rest, and fewer rounds. The key is gradual progression rather than attempting maximum intensity from day one.
Q. Should I eat before a HIIT session?
A. A light meal with carbohydrates and protein 60 to 90 minutes before helps fuel performance. Examples include a banana with yoghurt or wholegrain toast with nut butter. Avoid heavy or greasy foods that may cause discomfort.
Q. How often should I do HIIT in a week?
A. Two to three sessions per week is ideal for most people. This frequency balances results with recovery, ensuring your body adapts without excessive strain.
