LES MILLS GRIT

30-Minute High-Intensity Interval Training

What is LES MILLS GRIT?

LES MILLS GRIT is a 30-minute high-intensity interval training (HIIT) workout that improves cardiovascular fitness, increases speed, and makes you burn calories for hours after your workout. This scientifically-backed program pushes you to your limits in short bursts of intense exercise followed by recovery periods. The result? Maximum fitness gains in minimum time.

Three GRIT Formats

💪 GRIT STRENGTH

30-minute high-intensity interval training workout designed to improve strength and build lean muscle. Using barbells, weight plates, and bodyweight exercises, GRIT Strength challenges every major muscle group through powerful movements that overload the muscles.

Key Exercises:

Barbell squats and deadlifts
Clean and press variations
Weighted lunges and step-ups
Push-ups and chest presses
Bicep curls and tricep work

Best for: Building lean muscle, increasing strength, body recomposition

❤️ GRIT CARDIO

30-minute high-intensity interval training workout that improves cardiovascular fitness, increases speed, and burns maximum calories. Uses a step and bodyweight for explosive cardio training that drives your heart rate through the roof.

Key Exercises:

Burpees and jumping variations
Step overs and jump lunges
High knees and mountain climbers
Plyometric push-ups
Speed drills and agility work

Best for: Maximum calorie burn, cardiovascular fitness, endurance

⚡ GRIT ATHLETIC

30-minute plyometric-based high-intensity interval training workout designed to make you perform like an athlete. This sports-inspired session improves agility, power, and speed through explosive athletic movements.

Key Exercises:

Box jumps and tuck jumps
Lateral bounds and shuffles
Agility ladder drills
Power movements and sprints
Coordination challenges

Best for: Athletic performance, agility, power development

The Science of HIIT

What Makes HIIT So Effective?

High-Intensity Interval Training alternates between short bursts of intense exercise (85-100% max heart rate) and recovery periods. This training method triggers powerful metabolic adaptations that traditional steady-state cardio cannot match.

EPOC (Afterburn Effect)

Your body continues burning calories for up to 48 hours post-workout as it repairs and recovers. This “afterburn” can add 6-15% more calories to your total burn.

Metabolic Adaptation

HIIT improves how your body utilizes oxygen and fat for fuel. Your metabolism becomes more efficient, burning more calories at rest.

Hormonal Response

Intense exercise triggers growth hormone and testosterone release, promoting muscle growth and fat loss simultaneously.

Time Efficiency

30 minutes of HIIT produces fitness gains equivalent to 60+ minutes of moderate cardio. Maximum results in minimum time.

Benefits of LES MILLS GRIT

🔥 Burn Up to 400 Calories

In just 30 minutes, plus significant afterburn. Studies show total calorie expenditure including EPOC can exceed 600 calories per session.

💪 Build Lean Muscle

GRIT Strength specifically targets muscle hypertrophy while all formats recruit fast-twitch muscle fibers for power and definition.

❤️ Cardiovascular Fitness

Rapidly improve VO2 max – your body’s ability to use oxygen. Research shows HIIT improves cardio fitness 28% more than traditional endurance training.

⚡ Athletic Performance

Improve speed, power, and agility. GRIT Athletic specifically develops reactive strength and quick-twitch muscle activation.

⏱️ Time Efficient

30 minutes including warm-up and cool-down. Perfect for busy schedules – lunch break, before work, or quick evening session.

🧠 Mental Toughness

Pushing through intense intervals builds mental resilience that transfers to all areas of life. Develop grit – literally.

Class Structure

Every GRIT class follows a scientifically-designed structure:

Warm-Up (3-4 min)

Dynamic movements preparing muscles and joints. Gradually elevate heart rate for safe transition to high intensity.

Work Blocks (22-24 min)

Multiple rounds of work/rest intervals. Typically 30-45 seconds intense work followed by 15-30 seconds rest. Heart rate peaks and recovers repeatedly.

Cool-Down (3-4 min)

Stretching and heart rate recovery. Essential for muscle recovery and injury prevention.

Equipment by Format

GRIT Strength Equipment

Barbell and weight plates
Step/bench platform
Mat for floor work
Water bottle

GRIT Cardio Equipment

Step platform
Mat (optional)
Water bottle
Just your body!

GRIT Athletic Equipment

Step platform
Mat (optional)
Water bottle
Space to move laterally

Who Should Do GRIT?

✅ Ideal For:

Those short on time who want maximum results
People looking to break through fitness plateaus
Athletes wanting to improve performance
Anyone seeking rapid body composition changes
Fitness enthusiasts who enjoy intense challenges
Those who get bored with steady-state cardio

⚠️ Consider Modifications If:

You’re new to exercise (build base fitness first)
You have joint issues (lower-impact options available)
You have cardiovascular conditions (consult doctor first)
You’re pregnant (not recommended)

Pro tip: If you’re new to HIIT, try GRIT Cardio first – it’s the most scalable for beginners while still delivering intense results.

How Often Should You GRIT?

Recommended Frequency

2-3 GRIT sessions per week maximum. High-intensity training requires adequate recovery. More isn’t always better – overtraining leads to burnout, injury, and diminished results.

Sample Weekly Schedule:

Monday: GRIT Strength
Tuesday: BODYBALANCE or rest
Wednesday: GRIT Cardio
Thursday: BODYPUMP or active recovery
Friday: GRIT Athletic
Weekend: BODYBALANCE, light cardio, or rest

“GRIT completely transformed my fitness. I used to spend an hour on the treadmill with minimal results. Now in 30 minutes I get a better workout than I ever imagined. My body has never looked better, and I actually look forward to training.”
— David M., GRIT Member

Research & Results

Clinical Studies Support HIIT

Peer-reviewed research consistently demonstrates HIIT superiority:

Fat Loss: Studies show HIIT burns 28.5% more body fat than continuous moderate-intensity exercise
VO2 Max: 8 weeks of HIIT improves VO2 max more than 8 weeks of steady-state training
Insulin Sensitivity: HIIT improves insulin sensitivity and glucose regulation
Blood Pressure: Research shows significant reductions in both systolic and diastolic pressure
Muscle Preservation: Unlike long cardio, HIIT preserves muscle mass while burning fat

Frequently Asked Questions

Q: Which GRIT format should I start with?
A: GRIT Cardio is most beginner-friendly as intensity is easily adjusted. GRIT Strength requires weight lifting experience. GRIT Athletic suits those with athletic background.

Q: Can I do GRIT every day?
A: No! Maximum 3 times per week with rest days between. Your body needs recovery to adapt. Overtraining leads to injury and reduced results.

Q: Is GRIT good for weight loss?
A: Extremely effective. The combination of calorie burn, afterburn effect, and muscle building creates optimal conditions for fat loss and body recomposition.

Q: I’m not very fit. Can I still try GRIT?
A: Build base fitness first with programs like BODYPUMP or BODYATTACK. Once you can sustain 30 minutes of moderate exercise, try GRIT with modifications.

Q: How does GRIT compare to other HIIT workouts?
A: Les Mills scientifically designs each release with proven work/rest ratios, progressive overload, and periodization. It’s not random – it’s engineered for results.

Q: What heart rate should I target?
A: During work intervals, aim for 85-95% of max heart rate. During rest, actively recover to 65-75%. A heart rate monitor helps track intensity.

30 Minutes. Maximum Results.

No time for excuses. LES MILLS GRIT delivers fitness transformation in just half an hour.

Train Hard. Train Smart. Get GRIT.