Can You Build Muscle While Doing High-Intensity Workouts? Myth vs. Reality?

Many people wonder if high-intensity workouts—like CrossFit, Bootcamps, or circuit training—can help build muscle. The short answer? Yes, but only if done the right way.
If you love fast-paced workouts but still want to get stronger, this guide will help you understand how to build muscle while doing high-intensity training—and how the YMCA can help you reach your goals!

What Is High-Intensity Training?
High-intensity training (HIT) involves short bursts of hard effort followed by short rest periods. It keeps your heart rate up while working your muscles.
Some examples include:
•    CrossFit WODs (Workouts of the Day) – A mix of weightlifting, cardio, and bodyweight exercises.
Example: Doing squats, push-ups, and running in a timed circuit.
•    HIIT (High-Intensity Interval Training) – Short, explosive exercises with minimal rest in between.
Example: Sprinting for 30 seconds, resting for 10 seconds, then repeating.
•    Metabolic Conditioning (METCONs) – Workouts designed to burn calories and boost endurance.
Example: Doing burpees, kettlebell swings, and jump rope in a fast-paced circuit.

Can High-Intensity Training Build Muscle?
Yes—if you're a beginner!
If you’re new to exercise, almost any type of workout—including CrossFit, HIIT, or bodyweight exercises—will help you gain muscle at first. Your body is adapting to the new challenge!
No—if it’s your only training method long-term.
Over time, your body gets used to high-intensity workouts, and building muscle becomes harder. Here’s why:
1.    Lack of Progressive Overload – To build muscle, you must gradually increase resistance (like lifting heavier weights over time). HIT workouts often focus more on speed than strength. (Schoenfeld, 2010)
➡ Example: If you always do push-ups but never try harder versions (like weighted push-ups), your muscles stop growing.
2.    Too Much Cardio Can Limit Muscle Growth – High-rep, fast-paced circuits burn calories, but too much can reduce muscle-building signals. (Wilson et al., 2012)
➡ Example: Running 5 miles every day burns fat but doesn’t help build leg muscles as much as heavy squats.
3.    Not Enough Heavy Lifting – HIT workouts use weights, but often at lighter loads. Research shows lifting heavier weights with 6-12 reps per set is best for muscle growth. (Schoenfeld, 2016)
➡ Example: Lifting 50 lbs for 8 reps builds more muscle than lifting 20 lbs for 20 reps.

Why Do CrossFit Athletes Look So Muscular?
You might see CrossFit athletes and think, “They do HIT workouts and still have big muscles!”
But here’s the secret: They don’t just do fast-paced workouts—they lift heavy too!
Most CrossFit athletes include:
•    Heavy barbell lifts – Squats, deadlifts, presses, and Olympic lifts.
•    Strength-focused training – Exercises designed to increase power.
•    Accessory work – Isolation exercises for specific muscles.
Example: A strong CrossFit athlete doesn’t just do kettlebell swings—they also squat 200+ lbs!

Best Way to Build Muscle with High-Intensity Training
If you love HIT workouts but want to build muscle, here’s how to make it work:
•    Lift Heavy 2-4 Days a Week – Focus on squats, deadlifts, presses, and pull-ups with progressive overload.
Example: If you can squat 50 lbs today, try 55 lbs next week.
•    Limit Excessive Cardio – Too much cardio can slow muscle growth. Balance your training with strength workouts.
Example: Instead of running every day, try 3 days of weightlifting + 2 days of cardio.
•    Eat Enough Protein – Your muscles need protein to grow! Aim for 0.7-1.0 grams per pound of body weight.(Phillips & Van Loon, 2011)
Example: If you weigh 150 lbs, eat 105-150 grams of protein per day. (Chicken, eggs, fish, beans, and yogurt are great sources!)
•    Recover Properly – Overtraining can break down muscle instead of building it. Get enough sleep and take rest days.
Example: If your muscles feel sore and weak, take a day off or do light stretching.

How the YMCA Can Help You Build Muscle Safely
At the YMCA, you don’t have to figure this out alone! A personal trainer can help you:
•    Create a workout plan that balances strength and high-intensity training.
•    Teach you proper form to avoid injury and maximize muscle growth.
•    Track your progress so you keep improving over time.
•    Keep you accountable and motivated to stay consistent.
Want to get started? Come talk to a personal trainer at the YMCA and start building muscle the right way!