Can You Build Muscle Strength Without Increasing Muscle Mass?

Some women want to build lean body mass. After all, having a high muscle to fat ratio gives you a firm, toned appearance that makes you look healthy and strong. Other women want to become stronger but don’t want to increase muscle size. There are a number of reasons this might be. If you participate in certain sports like cycling, gymnastics or long-distance running, carrying more body mass can slow you down – but keep this in mind. Building muscle isn’t that easy for most women, regardless of how hard you lift. So don’t become preoccupied with becoming too bulky or muscle-bound. Is it possible to increase muscle strength without increasing muscle mass?

How Resistance Training Builds Muscle

You’re probably already familiar with how muscles increase in SIZE as a result of resistance training. When you overload a muscle through resistance training, it traumatizes the muscle tissue and its fibers, and immune cells enter the site to help clean up the damage. During this process, growth factors are released including chemicals like cytokines as well as a variety of hormones like insulin-like growth factor. These hormones and growth factors, especially insulin-like growth factor, activate satellite cells, cells that donate their nuclei to damaged muscle fibers to help them repair and grow. As a result, muscle fibers increase in size. To increase the size of a muscle, you progressively overload it by using a weight that’s challenging to lift AND do enough repetitions and volume to stimulate growth factors and satellite cell activation.

What about strength? Strength refers to the maximal force a muscle can generate, usually measured by one-rep max, the maximum amount of weight you can lift one time. Strength isn’t just about the muscle and its size. It has a strong brain and nervous system component. To gain muscle strength, you train your nervous system to recruit more muscle units and fire more motor neurons to those fibers to activate them. A motor unit is a group of muscle fibers activated by a single motor neuron. Motor units work together to stimulate the contraction of a muscle. More motor units activated translates into a more forceful contraction.

There’s also something called inhibitory neural feedback, a safety mechanism that keeps you from injuring yourself by lifting more weight than your muscles can handle. As you progress in your training, this feedback mechanism decreases, allowing you to lift more. It’s possible by training a certain way to build strength with little or no increase in muscle size. To do this, you need to reinforce these neural pathways so that more muscle units can be activated each time you lift.

Building Muscle Strength without Size

The best way to build muscle strength with minimal increase in muscle size is to lift a weight that’s heavy, around 90% of your one-rep max and do a lower number of reps. When you keep the reps low, between 3 to 5 reps, you strengthen neural pathways and the ability to recruit a greater percentage of muscle units to the muscle you’re training. If you lift heavy and stick with low reps, you’ll train your brain and nervous system to lift more without activating growth factors that increase muscle size. You’ll become stronger without becoming bigger. Your muscles need a certain amount of time under tension to activate the sequence of events that cause them to grow larger.

To boost strength without mass, keep the volume low. Do no more than two sets of each exercise and train each muscle group only once or twice a week. Increasing the volume will stimulate an increase in muscle size. Strength training is all about increasing neurological efficiency. This is something that’s independent of muscle size. You’ve probably seen people who have small muscles who can lift a significant amount of weight. Some of this ability may be genetic but they’re also able to maximize the activation of motor units to the muscles they’re using. You don’t have to have big muscles to be strong.

The Bottom Line?

You can increase muscle strength with little or no increase in muscle size by lifting heavy and reducing the volume of your resistance training sessions. You’ll train your brain and nervous system to increase the number of motor units that fire and the frequency with which they fire so you can lift more weight. By limiting training volume and the number of reps you do of each exercise, you won’t stimulate the release of growth factors that boost muscle growth. It’s another way to fine-tune your training to get the results you want.

References:

The University of New Mexico. “The Mystery of Skeletal Muscle Hypertrophy”

Poliquin, Charles. Modern Trends in Strength Training. Volume 1. (2001).

Exercise Physiology. McCardle, Katch, and Katch (2002)

Related Articles By Cathe:

Strength: It’s More Than the Size of Your Muscles

Lack of Exercise Is Even More Harmful to Your Muscles as You Get Older

Why Your Muscles Look Larger After a Resistance Workout

4 Reasons We Lose Strength as a Result of Loss of Muscle as We Age

Advanced Strength Training Using a Rest-Pause Approach

Strength Training: How Long Does It Take to See Results?

Related Cathe Friedrich Workout DVDs:

STS Strength 90 Day Workout Program

All of Cathe’s Strength & Toning Workout DVDs
Total Body Workouts
Lower Body Workouts
Upper Body Workouts