The best way to lose fat without sacrificing muscle also known as body recomposition combines resistance training, high intensity interval training (HIIT) and a proper diet.

Resistance Training

It's crucial to maintain muscle mass by engaging in strength training exercises 3-4 times per week. This ensures that your muscles are adequately stimulated to retain and even build strength and size. Focus on compound movements such as squats, deadlifts, bench presses and rows. These exercises work muscle groups simultaneously leading to increased energy expenditure and beneficial hormonal responses for preserving muscle.

• Aim for 3-4 sessions per week
• Include compound movements in your routine
• Use weights that allow you to perform 6-12 repetitions for muscle growth
• Maintain form to prevent injuries and effectively target muscles

High Intensity Interval Training (HIIT)

HIIT involves bursts of exercise followed by periods of rest or low intensity activity. This type of training effectively burns fat, boosts metabolism without requiring durations like steady state cardio does. Additionally, it helps preserve muscle mass, than prolonged cardio sessions.

• Aim to include 2-3 sessions of HIIT per week
• Perform bursts of high intensity such as 30 seconds followed by periods of rest or lower intensity for around 60 seconds
• You can do HIIT with exercises like sprinting, cycling, or bodyweight movements
• Keep your sessions brief but intense, typically lasting between 20 to 30 minutes

Nutrition

Your diet is just as crucial as your workout routine. To effectively reduce fat while maintaining muscle mass, it's important to be in a calorie deficit while ensuring a protein intake. Consuming protein supports muscle repair and growth which helps in preserving muscle mass.

• Consume an amount of protein within the range of 1.6 to 2.2 grams per kilogram of body weight (as recommended)
• Maintain a calorie deficit by consuming 10-20% fewer calories than your maintenance level
• Make sure that your diet is well balanced with carbohydrates, fats and proteins while providing essential nutrients

Consistency and Recovery

Consistency in workouts and maintaining a diet are factors. However, recovery is equally important. Ensure you get sleep and manage stress effectively. Consider incorporating rest days or active recovery activities to allow your muscles to repair and grow properly. Here are some important factors to consider for consistency and recovery:

• It's crucial to stick to your training and nutrition plan
• Make sure you prioritize getting sleep and managing stress effectively
• Plan rest. Incorporate recovery sessions into your routine to aid in the recovery process

When it comes to losing fat without sacrificing muscle, the effective workout program includes an approach. This means incorporating resistance training to maintain muscle mass, incorporating HIIT workouts for loss and following a protein diet to support muscle repair and growth.

If you're looking for information on these topics here are some resources:

1. The American Council on Exercise provides insights on strength training. You can find information here
2. The National Strength and Conditioning Association offers resources on HIIT workouts. Check out their article here
3. The International Society of Sports Nutrition has published research on protein intake for muscle gain. You can access their study here

Remember, an effective program is one that you can sustain long term aligned with your goals and incorporates workouts that you enjoy. It's always recommended to consult with fitness professionals when designing a workout regimen and registered dietitians for advice.