Building muscle is challenging and complicated. Understanding the difference between muscular strength and muscular endurance helps you to devise a strength training plan to meet your fitness goals. Many people desire a specific outcome from their workouts but unknowingly perform a workout that is contrary to their goals.
Muscular endurance refers to the ability to perform a specific muscular action for a prolonged period of time. For example, your ability to run a marathon or to pump out 100 squats with no added weight is due to muscular endurance. Muscular strength is a muscle’s capacity to exert force against resistance. Your ability to bench press a barbell weighing 200 lbs. for one repetition is a measure of your muscular strength.
Muscles are made up of different types of fibers called slow twitch—or type 1—and fast twitch—or type 2. Slow twitch fibers are responsible for endurance—the ability to go long on a treadmill or cycle. Fast twitch come in types A and B. Type A help you to endure a long sprint or carry a heavy object across the room, while type B are recruited for short, explosive moves, such as jumping or heaving a very heavy weight. According to exercise physiologist Jason Karp, Ph.D. on the IDEA Health and Fitness website, genetics determine what proportion of each fibers make up your muscles.
If you have a predomination of slow twitch fibers, you are better adapted to muscular endurance—you are able to perform long cardio sessions and multiple repetitions of a lighter weight. A person with more fast-twitch fibers is more adept at muscular strength--lifting heavy weights for a few repetitions or short, very high intensity anaerobic exercise. Karp notes, however, that if an endurance specialist wants to increase strength and speed—he can lift progressively increased weight during resistance training and add intervals of speed to their cardio routines. Similarly, if a person who excels at strength wants to increase their endurance, he should gradually increase cardio workout length and numbers of repetitions of resistance exercises as the workouts move forward.
Whether you emphasize strength or endurance training depends on your goals. If you are a bodybuilder or are looking to build muscle, then muscular strength should be your focus. Certain athletes, such as like power lifters, football players and rugby players, need strength and bulk to perform their sports. Athletes such as tennis players, basketball players and martial artists are best served by focusing on both endurance and strength training--specifically type A fast twitch fibers. They need power in short spurts to return a shot or sprint down a court, but they do not want to build huge muscles that impede their agility. Endurance training is best for triathletes, distance runners and rowers, reports the Sports Fitness Advisor website.
Women often train with light weights and multiple repetitions believing that this will result in toned, sculpted muscles and avoid creating “bulk.” While this does enhance the ability of your muscles to lift light weights for more and more repetitions, it does not build muscle. In the book “The New Rules of Lifting for Women,” fitness expert Lou Schuler points out that if you use weights that are unchallenging, your muscles will not grow. If you do not build muscle, you have nothing to sculpt and will not look lean and toned. Women, for the most part, do not have the muscle fiber size and type or the testosterone that creates “huge” unfeminine muscles.