As a Somers personal trainer, I’ve learned that many people believe that after 40, metabolism slows down to the point where weight gain is inevitable. But the truth is, your metabolism is not broken—and it’s not doomed to decline without a fight. While aging does bring metabolic changes, you have more control than you think over how efficiently your body burns calories and maintains energy.

Let’s break down the biggest metabolism myths and explore how you can keep your metabolism working for you, not against you.

Myth #1: Your Metabolism Slows Down Drastically After 40

The Truth: Yes, metabolism slows slightly, but the real culprit is muscle loss and lifestyle changes.

Many assume that metabolism takes a nosedive after 40, but research shows that resting metabolic rate (RMR) only declines by about 1-2% per decade. What makes the biggest difference? Loss of muscle mass and reduced activity levels.

How to Counter It:

• Strength train at least 2-3 times a week to preserve muscle.
• Increase daily movement (walking, standing, stretching).
• Prioritize protein intake to support muscle repair and maintenance.

Myth #2: You Can’t Lose Weight Because Your Metabolism Is “Broken”

The Truth: Metabolism doesn’t just “break.” It adapts based on your lifestyle and habits.

Many people blame their metabolism when weight loss stalls, but what’s actually happening is metabolic adaptation—your body adjusting to calorie intake and activity levels.

How to Reset Your Metabolism:

• Eat enough protein (0.7-1g per pound of body weight daily) to support metabolic activity.
• Cycle calorie intake strategically—periods of slightly higher and lower intake can prevent adaptation.
• Mix up workouts to avoid your body adapting to the same routine.

Myth #3: Cardio is the Best Way to Speed Up Metabolism

The Truth: Strength training has a greater long-term impact on metabolism than cardio alone.

Cardio burns calories in the moment, but it doesn’t do much for sustaining a higher metabolic rate throughout the day. Strength training, on the other hand, builds muscle, which in turn burns more calories even at rest.

What to Focus On:

• Combine strength training with cardio for maximum fat loss and metabolic efficiency.
• Prioritize compound movements (squats, deadlifts, push-ups) that engage multiple muscle groups.
• Include HIIT workouts for short bursts of calorie-burning intensity.

Myth #4: Eating Less is the Only Way to Speed Up Metabolism

The Truth: Chronically eating too little can actually slow metabolism over time.

Many people drastically cut calories in an attempt to “jumpstart” their metabolism, only to find themselves more fatigued, hungrier, and stuck in a plateau. When you consistently undereat, your body slows calorie burning to conserve energy.

A Better Approach:

• Eat enough calories to support activity levels.
• Focus on whole, nutrient-dense foods that keep energy stable.
• Include regular meals to avoid extreme dips in blood sugar and energy.

Myth #5: After 40, You Can’t Build Muscle or Improve Metabolism

The Truth: You can build muscle at any age, which directly supports a faster metabolism.

Your body continues to respond to resistance training and proper nutrition well beyond 40. Studies show that even people in their 60s and 70s can significantly improve muscle mass with strength training.

How to Build Metabolism-Boosting Muscle:

• Strength train consistently (2-4 times per week).
• Get enough protein and recovery time.
• Focus on progressive overload (gradually increasing weights or reps).

Myth #6: Hormones Are to Blame for a Slow Metabolism

The Truth: Hormones play a role, but they’re not the sole reason metabolism slows down.

Yes, hormonal shifts (like lower estrogen or testosterone levels) can slightly affect metabolism, but they don’t completely control your ability to maintain or lose weight.

What You Can Do:

• Get quality sleep (7-9 hours per night) to regulate hormones.
• Manage stress levels to prevent cortisol spikes (which can lead to fat storage).
• Stay hydrated—even mild dehydration can slow down calorie burning.

The Best Ways to Keep Your Metabolism Strong After 40

If you want to avoid metabolic slowdown and maintain high energy levels, focus on these key habits:

1. Prioritize Strength Training

• At least 2-3 strength workouts per week.
• Focus on progressive overload to challenge muscles.
• Don’t skip core and stability exercises for functional strength.

2. Eat for Metabolic Efficiency

• Get enough protein, fiber, and healthy fats.
• Avoid excessive processed foods and sugar crashes.
• Stay hydrated—water is essential for metabolism.

3. Move More Throughout the Day

• Take walking breaks instead of prolonged sitting.
• Try standing desks or active stretching at work.
• Find activities you enjoy, so movement feels natural.

4. Optimize Sleep and Recovery

• Sleep at least 7 hours to support metabolic function.
• Avoid screen exposure before bedtime to improve sleep quality.
• Manage stress through meditation, deep breathing, or journaling.

Final Thoughts: You Have More Control Over Your Metabolism Than You Think

Metabolism after 40 is not a lost cause—it’s highly adaptable and within your control. By focusing on strength training, proper nutrition, movement, and recovery, you can keep your metabolism strong for decades to come.

Ready to Take Control of Your Metabolism?

If you’re looking for a personalized fitness and nutrition plan to boost your metabolism and keep you feeling energized, I can help!