Weight training can add variety to your fitness routine while helping to enhance your muscle definition, improve your posture and accelerate weight-loss success. Resistance training largely falls into two categories -- strength and endurance. While not mutually exclusive, there are different training approaches depending on your resistance-training goals, as well as different results. Strengthening programs focus on building muscle size, while endurance-training programs focus on definition and fatigue resistance.
Each person is born with a finite number of muscle fibers. The size of the muscle fiber depends on genetics as well as the amount of work the fiber is subjected to on a daily basis. Muscle fiber growth, hypertrophy, is the process of increasing the size of the individual muscle fibers rather than the overall number of muscle fibers.
Muscular strength is the measure of the force your muscle can generate against resistance. To build muscular strength, the generally accepted practice is a routine of eight to 10 exercises with high weight and low repetitions. The weight you select to complete this type of training should be challenging to lift and should cause your muscles to fatigue by eight to 10 repetitions. Programs aimed toward generating muscular strength focus on the process of muscle hypertrophy.
Muscular endurance is a measure of the number of times your muscle can generate force against a resistance. A certain amount of muscular strength is needed in order to build muscular endurance. Programs geared toward developing muscular endurance rely on low weights and high repetitions. You should be challenged by the weight you select, but be able to lift for more than 10 repetitions. Programs aimed toward generating muscular endurance focus on the process of muscle fiber recruitment. In muscle fiber recruitment, over time a greater number of muscle fibers are cooperating to complete the same task rather than increasing the size of the muscle fiber itself.
Muscle strengthening results can be measured through muscle circumference measurements and tests such as the one-repetition maximum. Whereas muscle endurance can be measured by the number of repetitions you are able to complete in a given period of time. Visually, programs geared toward building muscle strength illustrate a change in muscle size and can give you a “bulked up” appearance, whereas muscle endurance programs will further define your muscles without adding a great deal of muscle mass.