Les Mills GRIT™ Strength: What It Is, Benefits, and Safety

What is a Grit Strength Class?

A Les Mills GRIT™ Strength class is a high-intensity interval training (HIIT) workout designed to build muscular strength, improve cardiovascular fitness, and enhance overall athletic performance using a barbell, weight plates, and bodyweight exercises.

Understanding Les Mills GRIT™ Strength

Les Mills GRIT™ Strength is one of three programs within the Les Mills GRIT™ series (alongside GRIT Cardio and GRIT Athletic). It is a highly structured, 30-minute group fitness class that combines short bursts of intense exercise with brief recovery periods. The primary focus of GRIT Strength is on developing strength and lean muscle mass through a variety of resistance training movements.

Key Characteristics:

• High-Intensity Interval Training (HIIT): The core methodology, involving maximum effort work periods followed by short rest.
• Resistance-Based: Utilizes a barbell, weight plates, and bodyweight exercises to challenge major muscle groups.
• Athletic Focus: Designed to improve power, speed, agility, and strength, mimicking the demands of athletic training.
• Coached Environment: Led by certified instructors who provide motivation, technique correction, and energy.
• Pre-Choreographed: Each release (new set of workouts) is meticulously designed by Les Mills, ensuring a consistent and effective training stimulus globally.

The Science Behind GRIT Strength: Why it Works

The effectiveness of GRIT Strength stems from its adherence to established exercise science principles, particularly those related to HIIT and resistance training.

Physiological Adaptations:

• Excess Post-exercise Oxygen Consumption (EPOC): The intense nature of GRIT Strength significantly elevates EPOC, meaning your body continues to burn calories at an accelerated rate even after the workout is complete, contributing to fat loss.
• Strength and Hypertrophy: The use of progressive resistance (barbells and plates) coupled with high repetitions and short rest periods stimulates muscle protein synthesis, leading to increases in muscular strength and hypertrophy (muscle growth).
• Anaerobic Capacity: The short, maximal effort intervals challenge the anaerobic energy systems, improving the body's ability to perform high-power activities and tolerate lactic acid accumulation.
• Mitochondrial Biogenesis: Regular HIIT can lead to an increase in the number and efficiency of mitochondria, enhancing the body's capacity for aerobic energy production.

Typical Class Structure and Equipment

A GRIT Strength class is precisely 30 minutes, broken down into distinct phases.

Class Structure:

• Warm-up (approx. 5 minutes): Prepares the body for the intense work ahead with dynamic movements and light resistance work, gradually increasing heart rate and activating target muscle groups.
• Working Sets (approx. 20 minutes): This is the core of the workout, consisting of several rounds or blocks. Each block typically features 2-4 exercises performed in an interval format (e.g., 40 seconds work, 20 seconds rest), often repeated 2-3 times. Exercises are compound movements targeting large muscle groups.
• Cool-down (approx. 5 minutes): Focuses on static stretching to improve flexibility and aid in recovery, bringing the heart rate back down gradually.

Equipment:

• Barbell: A lightweight, studio-specific barbell.
• Weight Plates: Various weight plates (typically 1.25kg, 2.5kg, 5kg, 10kg) to allow for progressive overload.
• Step/Bench: Often used for exercises like step-ups, box jumps, or elevated push-ups.

Who is GRIT Strength For?

GRIT Strength is not typically recommended for absolute beginners due to its high intensity and technical demands. It is best suited for:

• Experienced Exercisers: Individuals with a solid fitness base and familiarity with fundamental resistance training movements.
• Fitness Enthusiasts: Those looking to challenge themselves and push their physical limits.
• Athletes: Individuals seeking to improve their power, explosiveness, and anaerobic conditioning for sports performance.
• Plateau Breakers: People who feel their current training routine is no longer yielding results and need a new, intense stimulus.
• Time-Efficient Individuals: Anyone looking for a highly effective workout that can be completed in just 30 minutes.

Potential Benefits of Participating

Engaging in GRIT Strength classes regularly can yield a multitude of physical adaptations and health benefits:

• Increased Muscular Strength and Endurance: Develops both the maximum force your muscles can produce and their ability to sustain contractions over time.
• Enhanced Anaerobic Fitness: Improves the body's capacity to perform high-intensity, short-duration activities.
• Accelerated Fat Loss and Body Composition Improvements: The combination of HIIT and resistance training boosts metabolism and promotes lean muscle mass, leading to a more favorable body composition.
• Improved Power and Explosiveness: Exercises are often designed to develop fast-twitch muscle fibers, crucial for explosive movements.
• Cardiovascular Health: Despite being strength-focused, the high-intensity nature significantly challenges the cardiovascular system, improving heart health and endurance.
• Time Efficiency: Delivers a comprehensive and challenging workout in a compressed 30-minute format, ideal for busy schedules.

Important Considerations and Safety

While highly effective, GRIT Strength requires a mindful approach to ensure safety and maximize benefits.

• Intensity Level: This is a maximal effort workout. It's crucial to be honest about your current fitness level and build up to the intensity.
• Proper Form Over Weight: Always prioritize correct technique over lifting heavy weights. Poor form increases the risk of injury and diminishes the effectiveness of the exercise.
• Listen to Your Body: It's normal to feel challenged, but sharp pain is a warning sign. Modify exercises or take extra rest if needed.
• Consult a Professional: If you have pre-existing health conditions, injuries, or are new to high-intensity training, consult with a healthcare provider or a certified personal trainer before starting.
• Progression and Regression: Instructors will offer options to make exercises harder or easier. Don't be afraid to choose the option that suits your current ability.
• Recovery: Due to its intensity, adequate recovery (nutrition, sleep, rest days) is paramount to allow for muscle repair and adaptation.

Maximizing Your GRIT Strength Experience

To get the most out of your GRIT Strength classes and ensure sustainable progress:

• Nutrition: Fuel your body with a balanced diet rich in lean protein, complex carbohydrates, and healthy fats to support energy levels and muscle recovery.
• Recovery: Incorporate active recovery, stretching, foam rolling, and prioritize 7-9 hours of quality sleep per night.
• Consistency: Aim for 2-3 GRIT Strength sessions per week, allowing for rest days in between.
• Mind-Muscle Connection: Focus on engaging the target muscles during each exercise, rather than just moving the weight. This enhances effectiveness and reduces injury risk.
• Hydration: Stay well-hydrated before, during, and after your workout.